diff options
Diffstat (limited to 'arch/powerpc/net')
| -rw-r--r-- | arch/powerpc/net/Makefile | 9 | ||||
| -rw-r--r-- | arch/powerpc/net/bpf_jit.h | 229 | ||||
| -rw-r--r-- | arch/powerpc/net/bpf_jit_comp.c | 1422 | ||||
| -rw-r--r-- | arch/powerpc/net/bpf_jit_comp32.c | 1423 | ||||
| -rw-r--r-- | arch/powerpc/net/bpf_jit_comp64.c | 2036 | ||||
| -rw-r--r-- | arch/powerpc/net/bpf_timed_may_goto.S | 57 |
6 files changed, 5176 insertions, 0 deletions
diff --git a/arch/powerpc/net/Makefile b/arch/powerpc/net/Makefile new file mode 100644 index 000000000..7f9339bac --- /dev/null +++ b/arch/powerpc/net/Makefile @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Arch-specific network modules +# +obj-$(CONFIG_BPF_JIT) += bpf_jit_comp.o bpf_jit_comp$(BITS).o + +ifdef CONFIG_PPC64 +obj-$(CONFIG_BPF_JIT) += bpf_timed_may_goto.o +endif diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h new file mode 100644 index 000000000..f32de8704 --- /dev/null +++ b/arch/powerpc/net/bpf_jit.h @@ -0,0 +1,229 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * bpf_jit.h: BPF JIT compiler for PPC + * + * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation + * 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> + */ +#ifndef _BPF_JIT_H +#define _BPF_JIT_H + +#ifndef __ASSEMBLER__ + +#include <asm/types.h> +#include <asm/ppc-opcode.h> +#include <linux/build_bug.h> + +#ifdef CONFIG_PPC64_ELF_ABI_V1 +#define FUNCTION_DESCR_SIZE 24 +#else +#define FUNCTION_DESCR_SIZE 0 +#endif + +#define CTX_NIA(ctx) ((unsigned long)ctx->idx * 4) + +#define SZL sizeof(unsigned long) +#define BPF_INSN_SAFETY 64 +#define BPF_PPC_TAILCALL 8 + +#define PLANT_INSTR(d, idx, instr) \ + do { if (d) { (d)[idx] = instr; } idx++; } while (0) +#define EMIT(instr) PLANT_INSTR(image, ctx->idx, instr) + +/* Long jump; (unconditional 'branch') */ +#define PPC_JMP(dest) \ + do { \ + long offset = (long)(dest) - CTX_NIA(ctx); \ + if ((dest) != 0 && !is_offset_in_branch_range(offset)) { \ + pr_err_ratelimited("Branch offset 0x%lx (@%u) out of range\n", offset, ctx->idx); \ + return -ERANGE; \ + } \ + EMIT(PPC_RAW_BRANCH(offset)); \ + } while (0) + +/* "cond" here covers BO:BI fields. */ +#define PPC_BCC_SHORT(cond, dest) \ + do { \ + long offset = (long)(dest) - CTX_NIA(ctx); \ + if ((dest) != 0 && !is_offset_in_cond_branch_range(offset)) { \ + pr_err_ratelimited("Conditional branch offset 0x%lx (@%u) out of range\n", offset, ctx->idx); \ + return -ERANGE; \ + } \ + EMIT(PPC_INST_BRANCH_COND | (((cond) & 0x3ff) << 16) | (offset & 0xfffc)); \ + } while (0) + +/* When constant jump offset is known prior */ +#define PPC_BCC_CONST_SHORT(cond, offset) \ + do { \ + BUILD_BUG_ON(offset < -0x8000 || offset > 0x7fff || (offset & 0x3)); \ + EMIT(PPC_INST_BRANCH_COND | (((cond) & 0x3ff) << 16) | (offset & 0xfffc)); \ + } while (0) + +/* + * Sign-extended 32-bit immediate load + * + * If this is a dummy pass (!image), account for + * maximum possible instructions. + */ +#define PPC_LI32(d, i) do { \ + if (!image) \ + ctx->idx += 2; \ + else { \ + if ((int)(uintptr_t)(i) >= -32768 && \ + (int)(uintptr_t)(i) < 32768) \ + EMIT(PPC_RAW_LI(d, i)); \ + else { \ + EMIT(PPC_RAW_LIS(d, IMM_H(i))); \ + if (IMM_L(i)) \ + EMIT(PPC_RAW_ORI(d, d, IMM_L(i))); \ + } \ + } } while (0) + +#ifdef CONFIG_PPC64 + +/* If dummy pass (!image), account for maximum possible instructions */ +#define PPC_LI64(d, i) do { \ + if (!image) \ + ctx->idx += 5; \ + else { \ + if ((long)(i) >= -2147483648 && \ + (long)(i) < 2147483648) \ + PPC_LI32(d, i); \ + else { \ + if (!((uintptr_t)(i) & 0xffff800000000000ULL)) \ + EMIT(PPC_RAW_LI(d, ((uintptr_t)(i) >> 32) & \ + 0xffff)); \ + else { \ + EMIT(PPC_RAW_LIS(d, ((uintptr_t)(i) >> 48))); \ + if ((uintptr_t)(i) & 0x0000ffff00000000ULL) \ + EMIT(PPC_RAW_ORI(d, d, \ + ((uintptr_t)(i) >> 32) & 0xffff)); \ + } \ + EMIT(PPC_RAW_SLDI(d, d, 32)); \ + if ((uintptr_t)(i) & 0x00000000ffff0000ULL) \ + EMIT(PPC_RAW_ORIS(d, d, \ + ((uintptr_t)(i) >> 16) & 0xffff)); \ + if ((uintptr_t)(i) & 0x000000000000ffffULL) \ + EMIT(PPC_RAW_ORI(d, d, (uintptr_t)(i) & \ + 0xffff)); \ + } \ + } } while (0) +#define PPC_LI_ADDR PPC_LI64 + +#ifndef CONFIG_PPC_KERNEL_PCREL +#define PPC64_LOAD_PACA() \ + EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc))) +#else +#define PPC64_LOAD_PACA() do {} while (0) +#endif +#else +#define PPC_LI64(d, i) BUILD_BUG() +#define PPC_LI_ADDR PPC_LI32 +#define PPC64_LOAD_PACA() BUILD_BUG() +#endif + +/* + * The fly in the ointment of code size changing from pass to pass is + * avoided by padding the short branch case with a NOP. If code size differs + * with different branch reaches we will have the issue of code moving from + * one pass to the next and will need a few passes to converge on a stable + * state. + */ +#define PPC_BCC(cond, dest) do { \ + if (is_offset_in_cond_branch_range((long)(dest) - CTX_NIA(ctx))) { \ + PPC_BCC_SHORT(cond, dest); \ + EMIT(PPC_RAW_NOP()); \ + } else { \ + /* Flip the 'T or F' bit to invert comparison */ \ + PPC_BCC_SHORT(cond ^ COND_CMP_TRUE, CTX_NIA(ctx) + 2*4); \ + PPC_JMP(dest); \ + } } while(0) + +/* To create a branch condition, select a bit of cr0... */ +#define CR0_LT 0 +#define CR0_GT 1 +#define CR0_EQ 2 +/* ...and modify BO[3] */ +#define COND_CMP_TRUE 0x100 +#define COND_CMP_FALSE 0x000 +/* Together, they make all required comparisons: */ +#define COND_GT (CR0_GT | COND_CMP_TRUE) +#define COND_GE (CR0_LT | COND_CMP_FALSE) +#define COND_EQ (CR0_EQ | COND_CMP_TRUE) +#define COND_NE (CR0_EQ | COND_CMP_FALSE) +#define COND_LT (CR0_LT | COND_CMP_TRUE) +#define COND_LE (CR0_GT | COND_CMP_FALSE) + +#define SEEN_FUNC 0x20000000 /* might call external helpers */ +#define SEEN_TAILCALL 0x40000000 /* uses tail calls */ + +struct codegen_context { + /* + * This is used to track register usage as well + * as calls to external helpers. + * - register usage is tracked with corresponding + * bits (r3-r31) + * - rest of the bits can be used to track other + * things -- for now, we use bits 0 to 2 + * encoded in SEEN_* macros above + */ + unsigned int seen; + unsigned int idx; + unsigned int stack_size; + int b2p[MAX_BPF_JIT_REG + 3]; + unsigned int exentry_idx; + unsigned int alt_exit_addr; + u64 arena_vm_start; + u64 user_vm_start; + bool is_subprog; + bool exception_boundary; + bool exception_cb; + void __percpu *priv_sp; + unsigned int priv_stack_size; +}; + +/* Memory size & magic-value to detect private stack overflow/underflow */ +#define PRIV_STACK_GUARD_SZ 16 +#define PRIV_STACK_GUARD_VAL 0xEB9F12345678eb9fULL + +#define bpf_to_ppc(r) (ctx->b2p[r]) + +#ifdef CONFIG_PPC32 +#define BPF_FIXUP_LEN 3 /* Three instructions => 12 bytes */ +#else +#define BPF_FIXUP_LEN 2 /* Two instructions => 8 bytes */ +#endif + +static inline bool bpf_is_seen_register(struct codegen_context *ctx, int i) +{ + return ctx->seen & (1 << (31 - i)); +} + +static inline void bpf_set_seen_register(struct codegen_context *ctx, int i) +{ + ctx->seen |= 1 << (31 - i); +} + +static inline void bpf_clear_seen_register(struct codegen_context *ctx, int i) +{ + ctx->seen &= ~(1 << (31 - i)); +} + +void bpf_jit_init_reg_mapping(struct codegen_context *ctx); +int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, struct codegen_context *ctx, u64 func); +int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct codegen_context *ctx, + u32 *addrs, int pass, bool extra_pass); +void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx); +void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx); +void bpf_jit_build_fentry_stubs(u32 *image, struct codegen_context *ctx); +void bpf_jit_realloc_regs(struct codegen_context *ctx); +int bpf_jit_emit_exit_insn(u32 *image, struct codegen_context *ctx, int tmp_reg, long exit_addr); +void prepare_for_fsession_fentry(u32 *image, struct codegen_context *ctx, int cookie_cnt, + int cookie_off, int retval_off); +void store_func_meta(u32 *image, struct codegen_context *ctx, u64 func_meta, int func_meta_off); +int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, u32 *fimage, int pass, + struct codegen_context *ctx, int insn_idx, + int jmp_off, int dst_reg, u32 code); +#endif + +#endif diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c new file mode 100644 index 000000000..7b07b4357 --- /dev/null +++ b/arch/powerpc/net/bpf_jit_comp.c @@ -0,0 +1,1422 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * eBPF JIT compiler + * + * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> + * IBM Corporation + * + * Based on the powerpc classic BPF JIT compiler by Matt Evans + */ +#include <linux/moduleloader.h> +#include <asm/cacheflush.h> +#include <asm/asm-compat.h> +#include <linux/netdevice.h> +#include <linux/filter.h> +#include <linux/if_vlan.h> +#include <linux/kernel.h> +#include <linux/memory.h> +#include <linux/bpf.h> + +#include <asm/kprobes.h> +#include <asm/text-patching.h> + +#include "bpf_jit.h" + +/* These offsets are from bpf prog end and stay the same across progs */ +static int bpf_jit_ool_stub, bpf_jit_long_branch_stub; + +static void bpf_jit_fill_ill_insns(void *area, unsigned int size) +{ + memset32(area, BREAKPOINT_INSTRUCTION, size / 4); +} + +void dummy_tramp(void); + +asm ( +" .pushsection .text, \"ax\", @progbits ;" +" .global dummy_tramp ;" +" .type dummy_tramp, @function ;" +"dummy_tramp: ;" +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE +" blr ;" +#else +/* LR is always in r11, so we don't need a 'mflr r11' here */ +" mtctr 11 ;" +" mtlr 0 ;" +" bctr ;" +#endif +" .size dummy_tramp, .-dummy_tramp ;" +" .popsection ;" +); + +void bpf_jit_build_fentry_stubs(u32 *image, struct codegen_context *ctx) +{ + int ool_stub_idx, long_branch_stub_idx; + + /* + * Out-of-line stub: + * mflr r0 + * [b|bl] tramp + * mtlr r0 // only with CONFIG_PPC_FTRACE_OUT_OF_LINE + * b bpf_func + 4 + */ + ool_stub_idx = ctx->idx; + EMIT(PPC_RAW_MFLR(_R0)); + EMIT(PPC_RAW_NOP()); + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) + EMIT(PPC_RAW_MTLR(_R0)); + WARN_ON_ONCE(!is_offset_in_branch_range(4 - (long)ctx->idx * 4)); + EMIT(PPC_RAW_BRANCH(4 - (long)ctx->idx * 4)); + + /* + * Long branch stub: + * .long <dummy_tramp_addr> + * mflr r11 + * bcl 20,31,$+4 + * mflr r12 + * ld r12, -8-SZL(r12) + * mtctr r12 + * mtlr r11 // needed to retain ftrace ABI + * bctr + */ + if (image) + *((unsigned long *)&image[ctx->idx]) = (unsigned long)dummy_tramp; + ctx->idx += SZL / 4; + long_branch_stub_idx = ctx->idx; + EMIT(PPC_RAW_MFLR(_R11)); + EMIT(PPC_RAW_BCL4()); + EMIT(PPC_RAW_MFLR(_R12)); + EMIT(PPC_RAW_LL(_R12, _R12, -8-SZL)); + EMIT(PPC_RAW_MTCTR(_R12)); + EMIT(PPC_RAW_MTLR(_R11)); + EMIT(PPC_RAW_BCTR()); + + if (!bpf_jit_ool_stub) { + bpf_jit_ool_stub = (ctx->idx - ool_stub_idx) * 4; + bpf_jit_long_branch_stub = (ctx->idx - long_branch_stub_idx) * 4; + } +} + +int bpf_jit_emit_exit_insn(u32 *image, struct codegen_context *ctx, int tmp_reg, long exit_addr) +{ + if (!exit_addr || is_offset_in_branch_range(exit_addr - (ctx->idx * 4))) { + PPC_JMP(exit_addr); + } else if (ctx->alt_exit_addr) { + if (WARN_ON(!is_offset_in_branch_range((long)ctx->alt_exit_addr - (ctx->idx * 4)))) + return -1; + PPC_JMP(ctx->alt_exit_addr); + } else { + ctx->alt_exit_addr = ctx->idx * 4; + bpf_jit_build_epilogue(image, ctx); + } + + return 0; +} + +struct powerpc_jit_data { + /* address of rw header */ + struct bpf_binary_header *hdr; + /* address of ro final header */ + struct bpf_binary_header *fhdr; + u32 *addrs; + u8 *fimage; + u32 proglen; + struct codegen_context ctx; +}; + +bool bpf_jit_needs_zext(void) +{ + return true; +} + +static void priv_stack_init_guard(void __percpu *priv_stack_ptr, int alloc_size) +{ + int cpu, underflow_idx = (alloc_size - PRIV_STACK_GUARD_SZ) >> 3; + u64 *stack_ptr; + + for_each_possible_cpu(cpu) { + stack_ptr = per_cpu_ptr(priv_stack_ptr, cpu); + stack_ptr[0] = PRIV_STACK_GUARD_VAL; + stack_ptr[1] = PRIV_STACK_GUARD_VAL; + stack_ptr[underflow_idx] = PRIV_STACK_GUARD_VAL; + stack_ptr[underflow_idx + 1] = PRIV_STACK_GUARD_VAL; + } +} + +static void priv_stack_check_guard(void __percpu *priv_stack_ptr, int alloc_size, + struct bpf_prog *fp) +{ + int cpu, underflow_idx = (alloc_size - PRIV_STACK_GUARD_SZ) >> 3; + u64 *stack_ptr; + + for_each_possible_cpu(cpu) { + stack_ptr = per_cpu_ptr(priv_stack_ptr, cpu); + if (stack_ptr[0] != PRIV_STACK_GUARD_VAL || + stack_ptr[1] != PRIV_STACK_GUARD_VAL || + stack_ptr[underflow_idx] != PRIV_STACK_GUARD_VAL || + stack_ptr[underflow_idx + 1] != PRIV_STACK_GUARD_VAL) { + pr_err("BPF private stack overflow/underflow detected for prog %s\n", + bpf_jit_get_prog_name(fp)); + break; + } + } +} + +struct bpf_prog *bpf_int_jit_compile(struct bpf_verifier_env *env, struct bpf_prog *fp) +{ + u32 proglen; + u32 alloclen; + u8 *image = NULL; + u32 *code_base = NULL; + u32 *addrs = NULL; + struct powerpc_jit_data *jit_data = NULL; + struct codegen_context cgctx; + int pass; + int flen; + int priv_stack_alloc_size; + void __percpu *priv_stack_ptr = NULL; + struct bpf_binary_header *fhdr = NULL; + struct bpf_binary_header *hdr = NULL; + bool extra_pass = false; + u8 *fimage = NULL; + u32 *fcode_base = NULL; + u32 extable_len; + u32 fixup_len; + + if (!fp->jit_requested) + return fp; + + jit_data = fp->aux->jit_data; + if (!jit_data) { + jit_data = kzalloc_obj(*jit_data); + if (!jit_data) + return fp; + fp->aux->jit_data = jit_data; + } + + priv_stack_ptr = fp->aux->priv_stack_ptr; + if (!priv_stack_ptr && fp->aux->jits_use_priv_stack) { + /* + * Allocate private stack of size equivalent to + * verifier-calculated stack size plus two memory + * guard regions to detect private stack overflow + * and underflow. + */ + priv_stack_alloc_size = round_up(fp->aux->stack_depth, 16) + + 2 * PRIV_STACK_GUARD_SZ; + priv_stack_ptr = __alloc_percpu_gfp(priv_stack_alloc_size, 16, GFP_KERNEL); + if (!priv_stack_ptr) + goto out_priv_stack; + + priv_stack_init_guard(priv_stack_ptr, priv_stack_alloc_size); + fp->aux->priv_stack_ptr = priv_stack_ptr; + } + + flen = fp->len; + addrs = jit_data->addrs; + if (addrs) { + cgctx = jit_data->ctx; + /* + * JIT compiled to a writable location (image/code_base) first. + * It is then moved to the readonly final location (fimage/fcode_base) + * using instruction patching. + */ + fimage = jit_data->fimage; + fhdr = jit_data->fhdr; + proglen = jit_data->proglen; + hdr = jit_data->hdr; + image = (void *)hdr + ((void *)fimage - (void *)fhdr); + extra_pass = true; + /* During extra pass, ensure index is reset before repopulating extable entries */ + cgctx.exentry_idx = 0; + goto skip_init_ctx; + } + + addrs = kcalloc(flen + 1, sizeof(*addrs), GFP_KERNEL); + if (addrs == NULL) + goto out_err; + + memset(&cgctx, 0, sizeof(struct codegen_context)); + bpf_jit_init_reg_mapping(&cgctx); + + /* Make sure that the stack is quadword aligned. */ + cgctx.stack_size = round_up(fp->aux->stack_depth, 16); + cgctx.arena_vm_start = bpf_arena_get_kern_vm_start(fp->aux->arena); + cgctx.user_vm_start = bpf_arena_get_user_vm_start(fp->aux->arena); + cgctx.is_subprog = bpf_is_subprog(fp); + cgctx.exception_boundary = fp->aux->exception_boundary; + cgctx.exception_cb = fp->aux->exception_cb; + cgctx.priv_sp = priv_stack_ptr; + cgctx.priv_stack_size = 0; + if (priv_stack_ptr) { + /* + * priv_stack_size required for setting bpf FP inside + * percpu allocation. + * stack_size is marked 0 to prevent allocation on + * general stack and offset calculation don't go for + * a toss in bpf_jit_stack_offsetof() & bpf_jit_stack_local() + */ + cgctx.priv_stack_size = cgctx.stack_size; + cgctx.stack_size = 0; + } + + /* Scouting faux-generate pass 0 */ + if (bpf_jit_build_body(fp, NULL, NULL, &cgctx, addrs, 0, false)) + /* We hit something illegal or unsupported. */ + goto out_err; + + /* + * If we have seen a tail call, we need a second pass. + * This is because bpf_jit_emit_common_epilogue() is called + * from bpf_jit_emit_tail_call() with a not yet stable ctx->seen. + * We also need a second pass if we ended up with too large + * a program so as to ensure BPF_EXIT branches are in range. + */ + if (cgctx.seen & SEEN_TAILCALL || !is_offset_in_branch_range((long)cgctx.idx * 4)) { + cgctx.idx = 0; + if (bpf_jit_build_body(fp, NULL, NULL, &cgctx, addrs, 0, false)) + goto out_err; + } + + bpf_jit_realloc_regs(&cgctx); + /* + * Pretend to build prologue, given the features we've seen. This will + * update ctgtx.idx as it pretends to output instructions, then we can + * calculate total size from idx. + */ + bpf_jit_build_prologue(NULL, &cgctx); + addrs[fp->len] = cgctx.idx * 4; + bpf_jit_build_epilogue(NULL, &cgctx); + + fixup_len = fp->aux->num_exentries * BPF_FIXUP_LEN * 4; + extable_len = fp->aux->num_exentries * sizeof(struct exception_table_entry); + + proglen = cgctx.idx * 4; + alloclen = proglen + FUNCTION_DESCR_SIZE + fixup_len + extable_len; + + fhdr = bpf_jit_binary_pack_alloc(alloclen, &fimage, 4, &hdr, &image, + bpf_jit_fill_ill_insns, bpf_prog_was_classic(fp)); + if (!fhdr) + goto out_err; + + if (extable_len) + fp->aux->extable = (void *)fimage + FUNCTION_DESCR_SIZE + proglen + fixup_len; + +skip_init_ctx: + code_base = (u32 *)(image + FUNCTION_DESCR_SIZE); + fcode_base = (u32 *)(fimage + FUNCTION_DESCR_SIZE); + + /* Code generation passes 1-2 */ + for (pass = 1; pass < 3; pass++) { + /* Now build the prologue, body code & epilogue for real. */ + cgctx.idx = 0; + cgctx.alt_exit_addr = 0; + bpf_jit_build_prologue(code_base, &cgctx); + if (bpf_jit_build_body(fp, code_base, fcode_base, &cgctx, addrs, pass, + extra_pass)) { + bpf_arch_text_copy(&fhdr->size, &hdr->size, sizeof(hdr->size)); + bpf_jit_binary_pack_free(fhdr, hdr); + goto out_err; + } + bpf_jit_build_epilogue(code_base, &cgctx); + + if (bpf_jit_enable > 1) + pr_info("Pass %d: shrink = %d, seen = 0x%x\n", pass, + proglen - (cgctx.idx * 4), cgctx.seen); + } + + if (bpf_jit_enable > 1) + /* + * Note that we output the base address of the code_base + * rather than image, since opcodes are in code_base. + */ + bpf_jit_dump(flen, proglen, pass, code_base); + +#ifdef CONFIG_PPC64_ELF_ABI_V1 + /* Function descriptor nastiness: Address + TOC */ + ((u64 *)image)[0] = (u64)fcode_base; + ((u64 *)image)[1] = local_paca->kernel_toc; +#endif + + if (!fp->is_func || extra_pass) { + if (bpf_jit_binary_pack_finalize(fhdr, hdr)) + goto out_err; + } + + fp->bpf_func = (void *)fimage; + fp->jited = 1; + fp->jited_len = cgctx.idx * 4 + FUNCTION_DESCR_SIZE; + + if (!fp->is_func || extra_pass) { + bpf_prog_fill_jited_linfo(fp, addrs); + /* + * On ABI V1, executable code starts after the function + * descriptor, so adjust base accordingly. + */ + bpf_prog_update_insn_ptrs(fp, addrs, + (void *)fimage + FUNCTION_DESCR_SIZE); + +out_addrs: + if (!image && priv_stack_ptr) { + fp->aux->priv_stack_ptr = NULL; + free_percpu(priv_stack_ptr); + } +out_priv_stack: + kfree(addrs); + kfree(jit_data); + fp->aux->jit_data = NULL; + } else { + jit_data->addrs = addrs; + jit_data->ctx = cgctx; + jit_data->proglen = proglen; + jit_data->fimage = fimage; + jit_data->fhdr = fhdr; + jit_data->hdr = hdr; + } + + return fp; + +out_err: + if (extra_pass) { + fp->bpf_func = NULL; + fp->jited = 0; + fp->jited_len = 0; + } + goto out_addrs; +} + +/* + * The caller should check for (BPF_MODE(code) == BPF_PROBE_MEM) before calling + * this function, as this only applies to BPF_PROBE_MEM, for now. + */ +int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, u32 *fimage, int pass, + struct codegen_context *ctx, int insn_idx, int jmp_off, + int dst_reg, u32 code) +{ + off_t offset; + unsigned long pc; + struct exception_table_entry *ex, *ex_entry; + u32 *fixup; + + /* Populate extable entries only in the last pass */ + if (pass != 2) + return 0; + + if (!fp->aux->extable || + WARN_ON_ONCE(ctx->exentry_idx >= fp->aux->num_exentries)) + return -EINVAL; + + /* + * Program is first written to image before copying to the + * final location (fimage). Accordingly, update in the image first. + * As all offsets used are relative, copying as is to the + * final location should be alright. + */ + pc = (unsigned long)&image[insn_idx]; + ex = (void *)fp->aux->extable - (void *)fimage + (void *)image; + + fixup = (void *)ex - + (fp->aux->num_exentries * BPF_FIXUP_LEN * 4) + + (ctx->exentry_idx * BPF_FIXUP_LEN * 4); + + fixup[0] = PPC_RAW_LI(dst_reg, 0); + if (BPF_CLASS(code) == BPF_ST || BPF_CLASS(code) == BPF_STX) + fixup[0] = PPC_RAW_NOP(); + + if (IS_ENABLED(CONFIG_PPC32)) + fixup[1] = PPC_RAW_LI(dst_reg - 1, 0); /* clear higher 32-bit register too */ + + fixup[BPF_FIXUP_LEN - 1] = + PPC_RAW_BRANCH((long)(pc + jmp_off) - (long)&fixup[BPF_FIXUP_LEN - 1]); + + ex_entry = &ex[ctx->exentry_idx]; + + offset = pc - (long)&ex_entry->insn; + if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN)) + return -ERANGE; + ex_entry->insn = offset; + + offset = (long)fixup - (long)&ex_entry->fixup; + if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN)) + return -ERANGE; + ex_entry->fixup = offset; + + ctx->exentry_idx++; + return 0; +} + +void *bpf_arch_text_copy(void *dst, void *src, size_t len) +{ + int err; + + if (WARN_ON_ONCE(core_kernel_text((unsigned long)dst))) + return ERR_PTR(-EINVAL); + + mutex_lock(&text_mutex); + err = patch_instructions(dst, src, len, false); + mutex_unlock(&text_mutex); + + return err ? ERR_PTR(err) : dst; +} + +int bpf_arch_text_invalidate(void *dst, size_t len) +{ + u32 insn = BREAKPOINT_INSTRUCTION; + int ret; + + if (WARN_ON_ONCE(core_kernel_text((unsigned long)dst))) + return -EINVAL; + + mutex_lock(&text_mutex); + ret = patch_instructions(dst, &insn, len, true); + mutex_unlock(&text_mutex); + + return ret; +} + +void bpf_jit_free(struct bpf_prog *fp) +{ + if (fp->jited) { + struct powerpc_jit_data *jit_data = fp->aux->jit_data; + struct bpf_binary_header *hdr; + void __percpu *priv_stack_ptr; + int priv_stack_alloc_size; + + /* + * If we fail the final pass of JIT (from jit_subprogs), + * the program may not be finalized yet. Call finalize here + * before freeing it. + */ + if (jit_data) { + bpf_jit_binary_pack_finalize(jit_data->fhdr, jit_data->hdr); + kvfree(jit_data->addrs); + kfree(jit_data); + } + hdr = bpf_jit_binary_pack_hdr(fp); + bpf_jit_binary_pack_free(hdr, NULL); + priv_stack_ptr = fp->aux->priv_stack_ptr; + if (priv_stack_ptr) { + priv_stack_alloc_size = round_up(fp->aux->stack_depth, 16) + + 2 * PRIV_STACK_GUARD_SZ; + priv_stack_check_guard(priv_stack_ptr, priv_stack_alloc_size, fp); + free_percpu(priv_stack_ptr); + } + WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); + } + + bpf_prog_unlock_free(fp); +} + +bool bpf_jit_supports_exceptions(void) +{ + return IS_ENABLED(CONFIG_PPC64); +} + +bool bpf_jit_supports_subprog_tailcalls(void) +{ + return IS_ENABLED(CONFIG_PPC64); +} + +bool bpf_jit_supports_timed_may_goto(void) +{ + return IS_ENABLED(CONFIG_PPC64); +} + +bool bpf_jit_supports_kfunc_call(void) +{ + return IS_ENABLED(CONFIG_PPC64); +} + +bool bpf_jit_supports_private_stack(void) +{ + return IS_ENABLED(CONFIG_PPC64); +} + +bool bpf_jit_supports_fsession(void) +{ + /* + * TODO: Remove after validating support + * for fsession and trampoline on ppc32. + */ + if (IS_ENABLED(CONFIG_PPC32)) + return -EOPNOTSUPP; + return true; +} + +bool bpf_jit_supports_arena(void) +{ + return IS_ENABLED(CONFIG_PPC64); +} + +bool bpf_jit_supports_far_kfunc_call(void) +{ + return IS_ENABLED(CONFIG_PPC64); +} + +bool bpf_jit_supports_insn(struct bpf_insn *insn, bool in_arena) +{ + if (!in_arena) + return true; + switch (insn->code) { + case BPF_STX | BPF_ATOMIC | BPF_H: + case BPF_STX | BPF_ATOMIC | BPF_B: + case BPF_STX | BPF_ATOMIC | BPF_W: + case BPF_STX | BPF_ATOMIC | BPF_DW: + if (bpf_atomic_is_load_store(insn)) + return false; + return IS_ENABLED(CONFIG_PPC64); + } + return true; +} + +bool bpf_jit_supports_percpu_insn(void) +{ + return IS_ENABLED(CONFIG_PPC64); +} + +bool bpf_jit_inlines_helper_call(s32 imm) +{ + switch (imm) { + case BPF_FUNC_get_smp_processor_id: + case BPF_FUNC_get_current_task: + case BPF_FUNC_get_current_task_btf: + return true; + default: + return false; + } +} + +void *arch_alloc_bpf_trampoline(unsigned int size) +{ + return bpf_prog_pack_alloc(size, bpf_jit_fill_ill_insns, false); +} + +void arch_free_bpf_trampoline(void *image, unsigned int size) +{ + bpf_prog_pack_free(image, size); +} + +int arch_protect_bpf_trampoline(void *image, unsigned int size) +{ + return 0; +} + +static int invoke_bpf_prog(u32 *image, u32 *ro_image, struct codegen_context *ctx, + struct bpf_tramp_node *n, int regs_off, int retval_off, + int run_ctx_off, bool save_ret) +{ + struct bpf_prog *p = n->link->prog; + ppc_inst_t branch_insn; + u32 jmp_idx; + int ret = 0; + + /* Save cookie */ + if (IS_ENABLED(CONFIG_PPC64)) { + PPC_LI64(_R3, n->cookie); + EMIT(PPC_RAW_STD(_R3, _R1, run_ctx_off + offsetof(struct bpf_tramp_run_ctx, + bpf_cookie))); + } else { + PPC_LI32(_R3, n->cookie >> 32); + PPC_LI32(_R4, n->cookie); + EMIT(PPC_RAW_STW(_R3, _R1, + run_ctx_off + offsetof(struct bpf_tramp_run_ctx, bpf_cookie))); + EMIT(PPC_RAW_STW(_R4, _R1, + run_ctx_off + offsetof(struct bpf_tramp_run_ctx, bpf_cookie) + 4)); + } + + /* __bpf_prog_enter(p, &bpf_tramp_run_ctx) */ + PPC_LI_ADDR(_R3, p); + EMIT(PPC_RAW_MR(_R25, _R3)); + EMIT(PPC_RAW_ADDI(_R4, _R1, run_ctx_off)); + ret = bpf_jit_emit_func_call_rel(image, ro_image, ctx, + (unsigned long)bpf_trampoline_enter(p)); + if (ret) + return ret; + + /* Remember prog start time returned by __bpf_prog_enter */ + EMIT(PPC_RAW_MR(_R26, _R3)); + + /* + * if (__bpf_prog_enter(p) == 0) + * goto skip_exec_of_prog; + * + * Emit a nop to be later patched with conditional branch, once offset is known + */ + EMIT(PPC_RAW_CMPLI(_R3, 0)); + jmp_idx = ctx->idx; + EMIT(PPC_RAW_NOP()); + + /* p->bpf_func(ctx) */ + EMIT(PPC_RAW_ADDI(_R3, _R1, regs_off)); + if (!p->jited) + PPC_LI_ADDR(_R4, (unsigned long)p->insnsi); + /* Account for max possible instructions during dummy pass for size calculation */ + if (image && !create_branch(&branch_insn, (u32 *)&ro_image[ctx->idx], + (unsigned long)p->bpf_func, + BRANCH_SET_LINK)) { + image[ctx->idx] = ppc_inst_val(branch_insn); + ctx->idx++; + } else { + EMIT(PPC_RAW_LL(_R12, _R25, offsetof(struct bpf_prog, bpf_func))); + EMIT(PPC_RAW_MTCTR(_R12)); + EMIT(PPC_RAW_BCTRL()); + } + + if (save_ret) + EMIT(PPC_RAW_STL(_R3, _R1, retval_off)); + + /* Fix up branch */ + if (image) { + if (create_cond_branch(&branch_insn, &image[jmp_idx], + (unsigned long)&image[ctx->idx], COND_EQ << 16)) + return -EINVAL; + image[jmp_idx] = ppc_inst_val(branch_insn); + } + + /* __bpf_prog_exit(p, start_time, &bpf_tramp_run_ctx) */ + EMIT(PPC_RAW_MR(_R3, _R25)); + EMIT(PPC_RAW_MR(_R4, _R26)); + EMIT(PPC_RAW_ADDI(_R5, _R1, run_ctx_off)); + ret = bpf_jit_emit_func_call_rel(image, ro_image, ctx, + (unsigned long)bpf_trampoline_exit(p)); + + return ret; +} + +static int invoke_bpf_mod_ret(u32 *image, u32 *ro_image, struct codegen_context *ctx, + struct bpf_tramp_nodes *tn, int regs_off, int retval_off, + int run_ctx_off, u32 *branches) +{ + int i; + + /* + * The first fmod_ret program will receive a garbage return value. + * Set this to 0 to avoid confusing the program. + */ + EMIT(PPC_RAW_LI(_R3, 0)); + EMIT(PPC_RAW_STL(_R3, _R1, retval_off)); + for (i = 0; i < tn->nr_nodes; i++) { + if (invoke_bpf_prog(image, ro_image, ctx, tn->nodes[i], regs_off, retval_off, + run_ctx_off, true)) + return -EINVAL; + + /* + * mod_ret prog stored return value after prog ctx. Emit: + * if (*(u64 *)(ret_val) != 0) + * goto do_fexit; + */ + EMIT(PPC_RAW_LL(_R3, _R1, retval_off)); + EMIT(PPC_RAW_CMPLI(_R3, 0)); + + /* + * Save the location of the branch and generate a nop, which is + * replaced with a conditional jump once do_fexit (i.e. the + * start of the fexit invocation) is finalized. + */ + branches[i] = ctx->idx; + EMIT(PPC_RAW_NOP()); + } + + return 0; +} + +/* + * Refer __arch_prepare_bpf_trampoline() for stack component details. + * + * The tailcall count/reference is present in caller's stack frame. The + * tail_call_info is saved at the same offset on the trampoline frame + * for the traced function (BPF subprog/callee) to fetch it. + */ +static void bpf_trampoline_setup_tail_call_info(u32 *image, struct codegen_context *ctx, + int bpf_frame_size, int r4_off) +{ + if (IS_ENABLED(CONFIG_PPC64)) { + EMIT(PPC_RAW_LD(_R4, _R1, bpf_frame_size)); + /* Refer to trampoline's Generated stack layout */ + EMIT(PPC_RAW_LD(_R3, _R4, -BPF_PPC_TAILCALL)); + + /* + * Setting the tail_call_info in trampoline's frame + * depending on if previous frame had value or reference. + */ + EMIT(PPC_RAW_CMPLWI(_R3, MAX_TAIL_CALL_CNT)); + PPC_BCC_CONST_SHORT(COND_GT, 8); + EMIT(PPC_RAW_ADDI(_R3, _R4, -BPF_PPC_TAILCALL)); + + /* + * Trampoline's tail_call_info is at the same offset, as that of + * any bpf program, with reference to previous frame. Update the + * address of main's tail_call_info in trampoline frame. + */ + EMIT(PPC_RAW_STL(_R3, _R1, bpf_frame_size - BPF_PPC_TAILCALL)); + } else { + /* See bpf_jit_stack_offsetof() and BPF_PPC_TC */ + EMIT(PPC_RAW_LL(_R4, _R1, r4_off)); + } +} + +static void bpf_trampoline_restore_tail_call_cnt(u32 *image, struct codegen_context *ctx, + int bpf_frame_size, int r4_off) +{ + if (IS_ENABLED(CONFIG_PPC32)) { + /* + * Restore tailcall for 32-bit powerpc + * See bpf_jit_stack_offsetof() and BPF_PPC_TC + */ + EMIT(PPC_RAW_STL(_R4, _R1, r4_off)); + } +} + +static void bpf_trampoline_save_args(u32 *image, struct codegen_context *ctx, + int bpf_frame_size, int nr_regs, int regs_off) +{ + int param_save_area_offset; + + param_save_area_offset = bpf_frame_size; + param_save_area_offset += STACK_FRAME_MIN_SIZE; /* param save area is past frame header */ + + for (int i = 0; i < nr_regs; i++) { + if (i < 8) { + EMIT(PPC_RAW_STL(_R3 + i, _R1, regs_off + i * SZL)); + } else { + EMIT(PPC_RAW_LL(_R3, _R1, param_save_area_offset + i * SZL)); + EMIT(PPC_RAW_STL(_R3, _R1, regs_off + i * SZL)); + } + } +} + +/* Used when restoring just the register parameters when returning back */ +static void bpf_trampoline_restore_args_regs(u32 *image, struct codegen_context *ctx, + int nr_regs, int regs_off) +{ + for (int i = 0; i < nr_regs && i < 8; i++) + EMIT(PPC_RAW_LL(_R3 + i, _R1, regs_off + i * SZL)); +} + +/* Used when we call into the traced function. Replicate parameter save area */ +static void bpf_trampoline_restore_args_stack(u32 *image, struct codegen_context *ctx, + int bpf_frame_size, int nr_regs, int regs_off) +{ + int param_save_area_offset; + + param_save_area_offset = bpf_frame_size; + param_save_area_offset += STACK_FRAME_MIN_SIZE; /* param save area is past frame header */ + + for (int i = 8; i < nr_regs; i++) { + EMIT(PPC_RAW_LL(_R3, _R1, param_save_area_offset + i * SZL)); + EMIT(PPC_RAW_STL(_R3, _R1, STACK_FRAME_MIN_SIZE + i * SZL)); + } + bpf_trampoline_restore_args_regs(image, ctx, nr_regs, regs_off); +} + +static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *rw_image, + void *rw_image_end, void *ro_image, + const struct btf_func_model *m, u32 flags, + struct bpf_tramp_nodes *tnodes, + void *func_addr) +{ + int regs_off, func_meta_off, ip_off, run_ctx_off, retval_off; + int nvr_off, alt_lr_off, r4_off = 0; + struct bpf_tramp_nodes *fmod_ret = &tnodes[BPF_TRAMP_MODIFY_RETURN]; + struct bpf_tramp_nodes *fentry = &tnodes[BPF_TRAMP_FENTRY]; + struct bpf_tramp_nodes *fexit = &tnodes[BPF_TRAMP_FEXIT]; + int i, ret, nr_regs, retaddr_off, bpf_frame_size = 0; + struct codegen_context codegen_ctx, *ctx; + int cookie_off, cookie_cnt, cookie_ctx_off; + int fsession_cnt = bpf_fsession_cnt(tnodes); + u64 func_meta; + u32 *image = (u32 *)rw_image; + ppc_inst_t branch_insn; + u32 *branches = NULL; + bool save_ret; + + if (IS_ENABLED(CONFIG_PPC32)) + return -EOPNOTSUPP; + + nr_regs = m->nr_args; + /* Extra registers for struct arguments */ + for (i = 0; i < m->nr_args; i++) + if (m->arg_size[i] > SZL) + nr_regs += round_up(m->arg_size[i], SZL) / SZL - 1; + + if (nr_regs > MAX_BPF_FUNC_ARGS) + return -EOPNOTSUPP; + + ctx = &codegen_ctx; + memset(ctx, 0, sizeof(*ctx)); + + /* + * Generated stack layout: + * + * func prev back chain [ back chain ] + * [ tail_call_info ] optional - 64-bit powerpc + * [ padding ] align stack frame + * r4_off [ r4 (tailcallcnt) ] optional - 32-bit powerpc + * alt_lr_off [ real lr (ool stub)] optional - actual lr + * retaddr_off [ return address ] + * [ r26 ] + * nvr_off [ r25 ] nvr save area + * retval_off [ return value ] + * [ reg argN ] + * [ ... ] + * regs_off [ reg_arg1 ] prog_ctx + * func_meta_off [ args count ] ((u64 *)prog_ctx)[-1] + * ip_off [ traced function ] ((u64 *)prog_ctx)[-2] + * [ stack cookieN ] + * [ ... ] + * cookie_off [ stack cookie1 ] + * run_ctx_off [ bpf_tramp_run_ctx ] + * [ reg argN ] + * [ ... ] + * param_save_area [ reg_arg1 ] min 8 doublewords, per ABI + * [ TOC save (64-bit) ] -- + * [ LR save (64-bit) ] | header + * [ LR save (32-bit) ] | + * bpf trampoline frame [ back chain 2 ] -- + * + */ + + /* Minimum stack frame header */ + bpf_frame_size = STACK_FRAME_MIN_SIZE; + + /* + * Room for parameter save area. + * + * As per the ABI, this is required if we call into the traced + * function (BPF_TRAMP_F_CALL_ORIG): + * - if the function takes more than 8 arguments for the rest to spill onto the stack + * - or, if the function has variadic arguments + * - or, if this functions's prototype was not available to the caller + * + * Reserve space for at least 8 registers for now. This can be optimized later. + */ + bpf_frame_size += (nr_regs > 8 ? nr_regs : 8) * SZL; + + /* Room for struct bpf_tramp_run_ctx */ + run_ctx_off = bpf_frame_size; + bpf_frame_size += round_up(sizeof(struct bpf_tramp_run_ctx), SZL); + + /* room for session cookies */ + cookie_off = bpf_frame_size; + cookie_cnt = bpf_fsession_cookie_cnt(tnodes); + bpf_frame_size += cookie_cnt * 8; + + /* Room for IP address argument */ + ip_off = bpf_frame_size; + if (flags & BPF_TRAMP_F_IP_ARG) + bpf_frame_size += SZL; + + /* Room for function metadata, arg regs count */ + func_meta_off = bpf_frame_size; + bpf_frame_size += SZL; + + /* Room for arg regs */ + regs_off = bpf_frame_size; + bpf_frame_size += nr_regs * SZL; + + /* Room for return value of func_addr or fentry prog */ + retval_off = bpf_frame_size; + save_ret = flags & (BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_RET_FENTRY_RET); + if (save_ret) + bpf_frame_size += SZL; + + /* Room for nvr save area */ + nvr_off = bpf_frame_size; + bpf_frame_size += 2 * SZL; + + /* Save area for return address */ + retaddr_off = bpf_frame_size; + bpf_frame_size += SZL; + + /* Optional save area for actual LR in case of ool ftrace */ + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) { + alt_lr_off = bpf_frame_size; + bpf_frame_size += SZL; + } + + if (IS_ENABLED(CONFIG_PPC32)) { + if (nr_regs < 2) { + r4_off = bpf_frame_size; + bpf_frame_size += SZL; + } else { + r4_off = regs_off + SZL; + } + } + + /* + * Save tailcall count pointer at the same offset on the + * stack where subprogs expect it + */ + if ((flags & BPF_TRAMP_F_CALL_ORIG) && + (flags & BPF_TRAMP_F_TAIL_CALL_CTX)) + bpf_frame_size += BPF_PPC_TAILCALL; + + /* Padding to align stack frame, if any */ + bpf_frame_size = round_up(bpf_frame_size, SZL * 2); + + /* Store original return value */ + EMIT(PPC_RAW_STL(_R0, _R1, PPC_LR_STKOFF)); + + /* Create our stack frame */ + EMIT(PPC_RAW_STLU(_R1, _R1, -bpf_frame_size)); + + /* 64-bit: Save TOC and load kernel TOC */ + if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2) && !IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) { + EMIT(PPC_RAW_STD(_R2, _R1, 24)); + PPC64_LOAD_PACA(); + } + + /* 32-bit: save tail call count in r4 */ + if (IS_ENABLED(CONFIG_PPC32) && nr_regs < 2) + EMIT(PPC_RAW_STL(_R4, _R1, r4_off)); + + bpf_trampoline_save_args(image, ctx, bpf_frame_size, nr_regs, regs_off); + + /* Save our LR/return address */ + EMIT(PPC_RAW_MFLR(_R3)); + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) + EMIT(PPC_RAW_STL(_R3, _R1, alt_lr_off)); + else + EMIT(PPC_RAW_STL(_R3, _R1, retaddr_off)); + + /* + * Derive IP address of the traced function. + * In case of CONFIG_PPC_FTRACE_OUT_OF_LINE or BPF program, LR points to the instruction + * after the 'bl' instruction in the OOL stub. Refer to ftrace_init_ool_stub() and + * bpf_arch_text_poke() for OOL stub of kernel functions and bpf programs respectively. + * Relevant stub sequence: + * + * bl <tramp> + * LR (R3) => mtlr r0 + * b <func_addr+4> + * + * Recover kernel function/bpf program address from the unconditional + * branch instruction at the end of OOL stub. + */ + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE) || flags & BPF_TRAMP_F_IP_ARG) { + EMIT(PPC_RAW_LWZ(_R4, _R3, 4)); + EMIT(PPC_RAW_SLWI(_R4, _R4, 6)); + EMIT(PPC_RAW_SRAWI(_R4, _R4, 6)); + EMIT(PPC_RAW_ADD(_R3, _R3, _R4)); + } + + if (flags & BPF_TRAMP_F_IP_ARG) + EMIT(PPC_RAW_STL(_R3, _R1, ip_off)); + + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) { + /* Fake our LR for BPF_TRAMP_F_CALL_ORIG case */ + EMIT(PPC_RAW_ADDI(_R3, _R3, 4)); + EMIT(PPC_RAW_STL(_R3, _R1, retaddr_off)); + } + + /* Save function arg regs count -- see bpf_get_func_arg_cnt() */ + func_meta = nr_regs; + store_func_meta(image, ctx, func_meta, func_meta_off); + + /* Save nv regs */ + EMIT(PPC_RAW_STL(_R25, _R1, nvr_off)); + EMIT(PPC_RAW_STL(_R26, _R1, nvr_off + SZL)); + + if (flags & BPF_TRAMP_F_CALL_ORIG) { + PPC_LI_ADDR(_R3, (unsigned long)im); + ret = bpf_jit_emit_func_call_rel(image, ro_image, ctx, + (unsigned long)__bpf_tramp_enter); + if (ret) + return ret; + } + + if (fsession_cnt) { + /* + * Clear all the session cookies' values + * Clear the return value to make sure fentry always get 0 + */ + prepare_for_fsession_fentry(image, ctx, cookie_cnt, cookie_off, retval_off); + } + + cookie_ctx_off = (regs_off - cookie_off) / 8; + + for (i = 0; i < fentry->nr_nodes; i++) { + if (bpf_prog_calls_session_cookie(fentry->nodes[i])) { + u64 meta = func_meta | (cookie_ctx_off << BPF_TRAMP_COOKIE_INDEX_SHIFT); + + store_func_meta(image, ctx, meta, func_meta_off); + cookie_ctx_off--; + } + + if (invoke_bpf_prog(image, ro_image, ctx, fentry->nodes[i], regs_off, retval_off, + run_ctx_off, flags & BPF_TRAMP_F_RET_FENTRY_RET)) + return -EINVAL; + } + + if (fmod_ret->nr_nodes) { + branches = kcalloc(fmod_ret->nr_nodes, sizeof(u32), GFP_KERNEL); + if (!branches) + return -ENOMEM; + + if (invoke_bpf_mod_ret(image, ro_image, ctx, fmod_ret, regs_off, retval_off, + run_ctx_off, branches)) { + ret = -EINVAL; + goto cleanup; + } + } + + /* Call the traced function */ + if (flags & BPF_TRAMP_F_CALL_ORIG) { + /* + * retaddr on trampoline stack points to the correct point in the original function + * with both PPC_FTRACE_OUT_OF_LINE as well as with traditional ftrace instruction + * sequence + */ + EMIT(PPC_RAW_LL(_R3, _R1, retaddr_off)); + EMIT(PPC_RAW_MTCTR(_R3)); + + /* Replicate tail_call_cnt before calling the original BPF prog */ + if (flags & BPF_TRAMP_F_TAIL_CALL_CTX) + bpf_trampoline_setup_tail_call_info(image, ctx, bpf_frame_size, r4_off); + + /* Restore args */ + bpf_trampoline_restore_args_stack(image, ctx, bpf_frame_size, nr_regs, regs_off); + + /* Restore TOC for 64-bit */ + if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2) && !IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) + EMIT(PPC_RAW_LD(_R2, _R1, 24)); + EMIT(PPC_RAW_BCTRL()); + if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2) && !IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) + PPC64_LOAD_PACA(); + + /* Store return value for bpf prog to access */ + EMIT(PPC_RAW_STL(_R3, _R1, retval_off)); + + /* Restore updated tail_call_cnt */ + if (flags & BPF_TRAMP_F_TAIL_CALL_CTX) + bpf_trampoline_restore_tail_call_cnt(image, ctx, bpf_frame_size, r4_off); + + /* Reserve space to patch branch instruction to skip fexit progs */ + if (ro_image) /* image is NULL for dummy pass */ + im->ip_after_call = &((u32 *)ro_image)[ctx->idx]; + EMIT(PPC_RAW_NOP()); + } + + /* Update branches saved in invoke_bpf_mod_ret with address of do_fexit */ + for (i = 0; i < fmod_ret->nr_nodes && image; i++) { + if (create_cond_branch(&branch_insn, &image[branches[i]], + (unsigned long)&image[ctx->idx], COND_NE << 16)) { + ret = -EINVAL; + goto cleanup; + } + + image[branches[i]] = ppc_inst_val(branch_insn); + } + + /* set the "is_return" flag for fsession */ + func_meta |= (1ULL << BPF_TRAMP_IS_RETURN_SHIFT); + if (fsession_cnt) + store_func_meta(image, ctx, func_meta, func_meta_off); + + cookie_ctx_off = (regs_off - cookie_off) / 8; + + for (i = 0; i < fexit->nr_nodes; i++) { + if (bpf_prog_calls_session_cookie(fexit->nodes[i])) { + u64 meta = func_meta | (cookie_ctx_off << BPF_TRAMP_COOKIE_INDEX_SHIFT); + + store_func_meta(image, ctx, meta, func_meta_off); + cookie_ctx_off--; + } + + if (invoke_bpf_prog(image, ro_image, ctx, fexit->nodes[i], regs_off, retval_off, + run_ctx_off, false)) { + ret = -EINVAL; + goto cleanup; + } + } + + if (flags & BPF_TRAMP_F_CALL_ORIG) { + if (ro_image) /* image is NULL for dummy pass */ + im->ip_epilogue = &((u32 *)ro_image)[ctx->idx]; + PPC_LI_ADDR(_R3, im); + ret = bpf_jit_emit_func_call_rel(image, ro_image, ctx, + (unsigned long)__bpf_tramp_exit); + if (ret) + goto cleanup; + } + + if (flags & BPF_TRAMP_F_RESTORE_REGS) + bpf_trampoline_restore_args_regs(image, ctx, nr_regs, regs_off); + + /* Restore return value of func_addr or fentry prog */ + if (save_ret) + EMIT(PPC_RAW_LL(_R3, _R1, retval_off)); + + /* Restore nv regs */ + EMIT(PPC_RAW_LL(_R26, _R1, nvr_off + SZL)); + EMIT(PPC_RAW_LL(_R25, _R1, nvr_off)); + + /* Epilogue */ + if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2) && !IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) + EMIT(PPC_RAW_LD(_R2, _R1, 24)); + if (flags & BPF_TRAMP_F_SKIP_FRAME) { + /* Skip the traced function and return to parent */ + EMIT(PPC_RAW_ADDI(_R1, _R1, bpf_frame_size)); + EMIT(PPC_RAW_LL(_R0, _R1, PPC_LR_STKOFF)); + EMIT(PPC_RAW_MTLR(_R0)); + EMIT(PPC_RAW_BLR()); + } else { + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) { + EMIT(PPC_RAW_LL(_R0, _R1, alt_lr_off)); + EMIT(PPC_RAW_MTLR(_R0)); + EMIT(PPC_RAW_ADDI(_R1, _R1, bpf_frame_size)); + EMIT(PPC_RAW_LL(_R0, _R1, PPC_LR_STKOFF)); + EMIT(PPC_RAW_BLR()); + } else { + EMIT(PPC_RAW_LL(_R0, _R1, retaddr_off)); + EMIT(PPC_RAW_MTCTR(_R0)); + EMIT(PPC_RAW_ADDI(_R1, _R1, bpf_frame_size)); + EMIT(PPC_RAW_LL(_R0, _R1, PPC_LR_STKOFF)); + EMIT(PPC_RAW_MTLR(_R0)); + EMIT(PPC_RAW_BCTR()); + } + } + + /* Make sure the trampoline generation logic doesn't overflow */ + if (image && WARN_ON_ONCE(&image[ctx->idx] > (u32 *)rw_image_end - BPF_INSN_SAFETY)) { + ret = -EFAULT; + goto cleanup; + } + ret = ctx->idx * 4 + BPF_INSN_SAFETY * 4; + +cleanup: + kfree(branches); + return ret; +} + +int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags, + struct bpf_tramp_nodes *tnodes, void *func_addr) +{ + struct bpf_tramp_image im; + int ret; + + ret = __arch_prepare_bpf_trampoline(&im, NULL, NULL, NULL, m, flags, tnodes, func_addr); + return ret; +} + +int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *image_end, + const struct btf_func_model *m, u32 flags, + struct bpf_tramp_nodes *tnodes, + void *func_addr) +{ + u32 size = image_end - image; + void *rw_image, *tmp; + int ret; + + /* + * rw_image doesn't need to be in module memory range, so we can + * use kvmalloc. + */ + rw_image = kvmalloc(size, GFP_KERNEL); + if (!rw_image) + return -ENOMEM; + + ret = __arch_prepare_bpf_trampoline(im, rw_image, rw_image + size, image, m, + flags, tnodes, func_addr); + if (ret < 0) + goto out; + + if (bpf_jit_enable > 1) + bpf_jit_dump(1, ret - BPF_INSN_SAFETY * 4, 1, rw_image); + + tmp = bpf_arch_text_copy(image, rw_image, size); + if (IS_ERR(tmp)) + ret = PTR_ERR(tmp); + +out: + kvfree(rw_image); + return ret; +} + +static int bpf_modify_inst(void *ip, ppc_inst_t old_inst, ppc_inst_t new_inst) +{ + ppc_inst_t org_inst; + + if (copy_inst_from_kernel_nofault(&org_inst, ip)) { + pr_err("0x%lx: fetching instruction failed\n", (unsigned long)ip); + return -EFAULT; + } + + if (!ppc_inst_equal(org_inst, old_inst)) { + pr_err("0x%lx: expected (%08lx) != found (%08lx)\n", + (unsigned long)ip, ppc_inst_as_ulong(old_inst), ppc_inst_as_ulong(org_inst)); + return -EINVAL; + } + + if (ppc_inst_equal(old_inst, new_inst)) + return 0; + + return patch_instruction(ip, new_inst); +} + +static void do_isync(void *info __maybe_unused) +{ + isync(); +} + +/* + * A 3-step process for bpf prog entry: + * 1. At bpf prog entry, a single nop/b: + * bpf_func: + * [nop|b] ool_stub + * 2. Out-of-line stub: + * ool_stub: + * mflr r0 + * [b|bl] <bpf_prog>/<long_branch_stub> + * mtlr r0 // CONFIG_PPC_FTRACE_OUT_OF_LINE only + * b bpf_func + 4 + * 3. Long branch stub: + * long_branch_stub: + * .long <branch_addr>/<dummy_tramp> + * mflr r11 + * bcl 20,31,$+4 + * mflr r12 + * ld r12, -16(r12) + * mtctr r12 + * mtlr r11 // needed to retain ftrace ABI + * bctr + * + * dummy_tramp is used to reduce synchronization requirements. + * + * When attaching a bpf trampoline to a bpf prog, we do not need any + * synchronization here since we always have a valid branch target regardless + * of the order in which the above stores are seen. dummy_tramp ensures that + * the long_branch stub goes to a valid destination on other cpus, even when + * the branch to the long_branch stub is seen before the updated trampoline + * address. + * + * However, when detaching a bpf trampoline from a bpf prog, or if changing + * the bpf trampoline address, we need synchronization to ensure that other + * cpus can no longer branch into the older trampoline so that it can be + * safely freed. bpf_tramp_image_put() uses rcu_tasks to ensure all cpus + * make forward progress, but we still need to ensure that other cpus + * execute isync (or some CSI) so that they don't go back into the + * trampoline again. + */ +int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t, + enum bpf_text_poke_type new_t, void *old_addr, + void *new_addr) +{ + unsigned long bpf_func, bpf_func_end, size, offset; + ppc_inst_t old_inst, new_inst; + int ret = 0, branch_flags; + char name[KSYM_NAME_LEN]; + + if (IS_ENABLED(CONFIG_PPC32)) + return -EOPNOTSUPP; + + bpf_func = (unsigned long)ip; + + /* We currently only support poking bpf programs */ + if (!bpf_address_lookup(bpf_func, &size, &offset, name)) { + pr_err("%s (0x%lx): kernel/modules are not supported\n", __func__, bpf_func); + return -EOPNOTSUPP; + } + + /* + * If we are not poking at bpf prog entry, then we are simply patching in/out + * an unconditional branch instruction at im->ip_after_call + */ + if (offset) { + if (old_t == BPF_MOD_CALL || new_t == BPF_MOD_CALL) { + pr_err("%s (0x%lx): calls are not supported in bpf prog body\n", __func__, + bpf_func); + return -EOPNOTSUPP; + } + old_inst = ppc_inst(PPC_RAW_NOP()); + if (old_addr) + if (create_branch(&old_inst, ip, (unsigned long)old_addr, 0)) + return -ERANGE; + new_inst = ppc_inst(PPC_RAW_NOP()); + if (new_addr) + if (create_branch(&new_inst, ip, (unsigned long)new_addr, 0)) + return -ERANGE; + mutex_lock(&text_mutex); + ret = bpf_modify_inst(ip, old_inst, new_inst); + mutex_unlock(&text_mutex); + + /* Make sure all cpus see the new instruction */ + smp_call_function(do_isync, NULL, 1); + return ret; + } + + bpf_func_end = bpf_func + size; + + /* Address of the jmp/call instruction in the out-of-line stub */ + ip = (void *)(bpf_func_end - bpf_jit_ool_stub + 4); + + if (!is_offset_in_branch_range((long)ip - 4 - bpf_func)) { + pr_err("%s (0x%lx): bpf prog too large, ool stub out of branch range\n", __func__, + bpf_func); + return -ERANGE; + } + + old_inst = ppc_inst(PPC_RAW_NOP()); + branch_flags = old_t == BPF_MOD_CALL ? BRANCH_SET_LINK : 0; + if (old_addr) { + if (is_offset_in_branch_range(ip - old_addr)) + create_branch(&old_inst, ip, (unsigned long)old_addr, branch_flags); + else + create_branch(&old_inst, ip, bpf_func_end - bpf_jit_long_branch_stub, + branch_flags); + } + new_inst = ppc_inst(PPC_RAW_NOP()); + branch_flags = new_t == BPF_MOD_CALL ? BRANCH_SET_LINK : 0; + if (new_addr) { + if (is_offset_in_branch_range(ip - new_addr)) + create_branch(&new_inst, ip, (unsigned long)new_addr, branch_flags); + else + create_branch(&new_inst, ip, bpf_func_end - bpf_jit_long_branch_stub, + branch_flags); + } + + mutex_lock(&text_mutex); + + /* + * 1. Update the address in the long branch stub: + * If new_addr is out of range, we will have to use the long branch stub, so patch new_addr + * here. Otherwise, revert to dummy_tramp, but only if we had patched old_addr here. + */ + if ((new_addr && !is_offset_in_branch_range(new_addr - ip)) || + (old_addr && !is_offset_in_branch_range(old_addr - ip))) + ret = patch_ulong((void *)(bpf_func_end - bpf_jit_long_branch_stub - SZL), + (new_addr && !is_offset_in_branch_range(new_addr - ip)) ? + (unsigned long)new_addr : (unsigned long)dummy_tramp); + if (ret) + goto out; + + /* 2. Update the branch/call in the out-of-line stub */ + ret = bpf_modify_inst(ip, old_inst, new_inst); + if (ret) + goto out; + + /* 3. Update instruction at bpf prog entry */ + ip = (void *)bpf_func; + if (!old_addr || !new_addr) { + if (!old_addr) { + old_inst = ppc_inst(PPC_RAW_NOP()); + create_branch(&new_inst, ip, bpf_func_end - bpf_jit_ool_stub, 0); + } else { + new_inst = ppc_inst(PPC_RAW_NOP()); + create_branch(&old_inst, ip, bpf_func_end - bpf_jit_ool_stub, 0); + } + ret = bpf_modify_inst(ip, old_inst, new_inst); + } + +out: + mutex_unlock(&text_mutex); + + /* + * Sync only if we are not attaching a trampoline to a bpf prog so the older + * trampoline can be freed safely. + */ + if (old_addr) + smp_call_function(do_isync, NULL, 1); + + return ret; +} diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c new file mode 100644 index 000000000..bfdc50740 --- /dev/null +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -0,0 +1,1423 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * eBPF JIT compiler for PPC32 + * + * Copyright 2020 Christophe Leroy <christophe.leroy@csgroup.eu> + * CS GROUP France + * + * Based on PPC64 eBPF JIT compiler by Naveen N. Rao + */ +#include <linux/moduleloader.h> +#include <asm/cacheflush.h> +#include <asm/asm-compat.h> +#include <linux/netdevice.h> +#include <linux/filter.h> +#include <linux/if_vlan.h> +#include <asm/kprobes.h> +#include <linux/bpf.h> + +#include "bpf_jit.h" + +/* + * Stack layout: + * + * [ prev sp ] <------------- + * [ nv gpr save area ] 16 * 4 | + * fp (r31) --> [ ebpf stack space ] upto 512 | + * [ frame header ] 16 | + * sp (r1) ---> [ stack pointer ] -------------- + */ + +/* for gpr non volatile registers r17 to r31 (14) + tail call */ +#define BPF_PPC_STACK_SAVE (15 * 4 + 4) +/* stack frame, ensure this is quadword aligned */ +#define BPF_PPC_STACKFRAME(ctx) (STACK_FRAME_MIN_SIZE + BPF_PPC_STACK_SAVE + (ctx)->stack_size) + +#define PPC_EX32(r, i) EMIT(PPC_RAW_LI((r), (i) < 0 ? -1 : 0)) + +/* PPC NVR range -- update this if we ever use NVRs below r17 */ +#define BPF_PPC_NVR_MIN _R17 +#define BPF_PPC_TC _R16 + +/* BPF register usage */ +#define TMP_REG (MAX_BPF_JIT_REG + 0) + +/* BPF to ppc register mappings */ +void bpf_jit_init_reg_mapping(struct codegen_context *ctx) +{ + /* function return value */ + ctx->b2p[BPF_REG_0] = _R12; + /* function arguments */ + ctx->b2p[BPF_REG_1] = _R4; + ctx->b2p[BPF_REG_2] = _R6; + ctx->b2p[BPF_REG_3] = _R8; + ctx->b2p[BPF_REG_4] = _R10; + ctx->b2p[BPF_REG_5] = _R22; + /* non volatile registers */ + ctx->b2p[BPF_REG_6] = _R24; + ctx->b2p[BPF_REG_7] = _R26; + ctx->b2p[BPF_REG_8] = _R28; + ctx->b2p[BPF_REG_9] = _R30; + /* frame pointer aka BPF_REG_10 */ + ctx->b2p[BPF_REG_FP] = _R18; + /* eBPF jit internal registers */ + ctx->b2p[BPF_REG_AX] = _R20; + ctx->b2p[TMP_REG] = _R31; /* 32 bits */ +} + +static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg) +{ + if ((reg >= BPF_PPC_NVR_MIN && reg < 32) || reg == BPF_PPC_TC) + return BPF_PPC_STACKFRAME(ctx) - 4 * (32 - reg); + + WARN(true, "BPF JIT is asking about unknown registers, will crash the stack"); + /* Use the hole we have left for alignment */ + return BPF_PPC_STACKFRAME(ctx) - 4; +} + +#define SEEN_VREG_MASK 0x1ff80000 /* Volatile registers r3-r12 */ +#define SEEN_NVREG_FULL_MASK 0x0003ffff /* Non volatile registers r14-r31 */ +#define SEEN_NVREG_TEMP_MASK 0x00001e01 /* BPF_REG_5, BPF_REG_AX, TMP_REG */ + +static inline bool bpf_has_stack_frame(struct codegen_context *ctx) +{ + /* + * We only need a stack frame if: + * - we call other functions (kernel helpers), or + * - we use non volatile registers, or + * - we use tail call counter + * - the bpf program uses its stack area + * The latter condition is deduced from the usage of BPF_REG_FP + */ + return ctx->seen & (SEEN_FUNC | SEEN_TAILCALL | SEEN_NVREG_FULL_MASK) || + bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP)); +} + +void bpf_jit_realloc_regs(struct codegen_context *ctx) +{ + unsigned int nvreg_mask; + + if (ctx->seen & SEEN_FUNC) + nvreg_mask = SEEN_NVREG_TEMP_MASK; + else + nvreg_mask = SEEN_NVREG_FULL_MASK; + + while (ctx->seen & nvreg_mask && + (ctx->seen & SEEN_VREG_MASK) != SEEN_VREG_MASK) { + int old = 32 - fls(ctx->seen & (nvreg_mask & 0xaaaaaaab)); + int new = 32 - fls(~ctx->seen & (SEEN_VREG_MASK & 0xaaaaaaaa)); + int i; + + for (i = BPF_REG_0; i <= TMP_REG; i++) { + if (ctx->b2p[i] != old) + continue; + ctx->b2p[i] = new; + bpf_set_seen_register(ctx, new); + bpf_clear_seen_register(ctx, old); + if (i != TMP_REG) { + bpf_set_seen_register(ctx, new - 1); + bpf_clear_seen_register(ctx, old - 1); + } + break; + } + } +} + +void prepare_for_fsession_fentry(u32 *image, struct codegen_context *ctx, int cookie_cnt, + int cookie_off, int retval_off) +{ + /* + * Set session cookies value + * Clear cookies field on stack + * Ensure retval to be cleared on fentry + */ + EMIT(PPC_RAW_LI(bpf_to_ppc(TMP_REG), 0)); + + for (int i = 0; i < cookie_cnt; i++) { + EMIT(PPC_RAW_STW(bpf_to_ppc(TMP_REG), _R1, cookie_off + 4 * i)); + EMIT(PPC_RAW_STW(bpf_to_ppc(TMP_REG), _R1, cookie_off + 4 * i + 4)); + } + + EMIT(PPC_RAW_STW(bpf_to_ppc(TMP_REG), _R1, retval_off)); + EMIT(PPC_RAW_STW(bpf_to_ppc(TMP_REG), _R1, retval_off + 4)); +} + +void store_func_meta(u32 *image, struct codegen_context *ctx, + u64 func_meta, int func_meta_off) +{ + /* + * Store func_meta to stack: [R1 + func_meta_off] = func_meta + * func_meta := argument count in first byte + cookie value + */ + /* Store lower word */ + PPC_LI32(bpf_to_ppc(TMP_REG), (u32)func_meta); + EMIT(PPC_RAW_STW(bpf_to_ppc(TMP_REG), _R1, func_meta_off)); + + /* Store upper word */ + PPC_LI32(bpf_to_ppc(TMP_REG), (u32)(func_meta >> 32)); + EMIT(PPC_RAW_STW(bpf_to_ppc(TMP_REG), _R1, func_meta_off + 4)); +} + +void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx) +{ + int i; + + /* Instruction for trampoline attach */ + EMIT(PPC_RAW_NOP()); + + /* Initialize tail_call_cnt, to be skipped if we do tail calls. */ + if (ctx->seen & SEEN_TAILCALL) + EMIT(PPC_RAW_LI(_R4, 0)); + else + EMIT(PPC_RAW_NOP()); + +#define BPF_TAILCALL_PROLOGUE_SIZE 8 + + if (bpf_has_stack_frame(ctx)) + EMIT(PPC_RAW_STWU(_R1, _R1, -BPF_PPC_STACKFRAME(ctx))); + + if (ctx->seen & SEEN_TAILCALL) + EMIT(PPC_RAW_STW(_R4, _R1, bpf_jit_stack_offsetof(ctx, BPF_PPC_TC))); + + /* First arg comes in as a 32 bits pointer. */ + EMIT(PPC_RAW_MR(bpf_to_ppc(BPF_REG_1), _R3)); + EMIT(PPC_RAW_LI(bpf_to_ppc(BPF_REG_1) - 1, 0)); + + /* + * We need a stack frame, but we don't necessarily need to + * save/restore LR unless we call other functions + */ + if (ctx->seen & SEEN_FUNC) + EMIT(PPC_RAW_MFLR(_R0)); + + /* + * Back up non-volatile regs -- registers r18-r31 + */ + for (i = BPF_PPC_NVR_MIN; i <= 31; i++) + if (bpf_is_seen_register(ctx, i)) + EMIT(PPC_RAW_STW(i, _R1, bpf_jit_stack_offsetof(ctx, i))); + + /* Setup frame pointer to point to the bpf stack area */ + if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP))) { + EMIT(PPC_RAW_LI(bpf_to_ppc(BPF_REG_FP) - 1, 0)); + EMIT(PPC_RAW_ADDI(bpf_to_ppc(BPF_REG_FP), _R1, + STACK_FRAME_MIN_SIZE + ctx->stack_size)); + } + + if (ctx->seen & SEEN_FUNC) + EMIT(PPC_RAW_STW(_R0, _R1, BPF_PPC_STACKFRAME(ctx) + PPC_LR_STKOFF)); +} + +static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx) +{ + int i; + + /* Restore NVRs */ + for (i = BPF_PPC_NVR_MIN; i <= 31; i++) + if (bpf_is_seen_register(ctx, i)) + EMIT(PPC_RAW_LWZ(i, _R1, bpf_jit_stack_offsetof(ctx, i))); + + if (ctx->seen & SEEN_FUNC) + EMIT(PPC_RAW_LWZ(_R0, _R1, BPF_PPC_STACKFRAME(ctx) + PPC_LR_STKOFF)); + + /* Tear down our stack frame */ + if (bpf_has_stack_frame(ctx)) + EMIT(PPC_RAW_ADDI(_R1, _R1, BPF_PPC_STACKFRAME(ctx))); + + if (ctx->seen & SEEN_FUNC) + EMIT(PPC_RAW_MTLR(_R0)); + +} + +void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) +{ + EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(BPF_REG_0))); + + bpf_jit_emit_common_epilogue(image, ctx); + + EMIT(PPC_RAW_BLR()); + + bpf_jit_build_fentry_stubs(image, ctx); +} + +/* Relative offset needs to be calculated based on final image location */ +int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, struct codegen_context *ctx, u64 func) +{ + s32 rel = (s32)func - (s32)(fimage + ctx->idx); + + if (image && rel < 0x2000000 && rel >= -0x2000000) { + EMIT(PPC_RAW_BL(rel)); + } else { + /* Load function address into r0 */ + EMIT(PPC_RAW_LIS(_R0, IMM_H(func))); + EMIT(PPC_RAW_ORI(_R0, _R0, IMM_L(func))); + EMIT(PPC_RAW_MTCTR(_R0)); + EMIT(PPC_RAW_BCTRL()); + } + + return 0; +} + +static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out) +{ + /* + * By now, the eBPF program has already setup parameters in r3-r6 + * r3-r4/BPF_REG_1 - pointer to ctx -- passed as is to the next bpf program + * r5-r6/BPF_REG_2 - pointer to bpf_array + * r7-r8/BPF_REG_3 - index in bpf_array + */ + int b2p_bpf_array = bpf_to_ppc(BPF_REG_2); + int b2p_index = bpf_to_ppc(BPF_REG_3); + + /* + * if (index >= array->map.max_entries) + * goto out; + */ + EMIT(PPC_RAW_LWZ(_R0, b2p_bpf_array, offsetof(struct bpf_array, map.max_entries))); + EMIT(PPC_RAW_CMPLW(b2p_index, _R0)); + EMIT(PPC_RAW_LWZ(_R0, _R1, bpf_jit_stack_offsetof(ctx, BPF_PPC_TC))); + PPC_BCC_SHORT(COND_GE, out); + + /* + * if (tail_call_cnt >= MAX_TAIL_CALL_CNT) + * goto out; + */ + EMIT(PPC_RAW_CMPLWI(_R0, MAX_TAIL_CALL_CNT)); + /* tail_call_cnt++; */ + EMIT(PPC_RAW_ADDIC(_R0, _R0, 1)); + PPC_BCC_SHORT(COND_GE, out); + + /* prog = array->ptrs[index]; */ + EMIT(PPC_RAW_RLWINM(_R3, b2p_index, 2, 0, 29)); + EMIT(PPC_RAW_ADD(_R3, _R3, b2p_bpf_array)); + EMIT(PPC_RAW_LWZ(_R3, _R3, offsetof(struct bpf_array, ptrs))); + + /* + * if (prog == NULL) + * goto out; + */ + EMIT(PPC_RAW_CMPLWI(_R3, 0)); + PPC_BCC_SHORT(COND_EQ, out); + + /* goto *(prog->bpf_func + prologue_size); */ + EMIT(PPC_RAW_LWZ(_R3, _R3, offsetof(struct bpf_prog, bpf_func))); + EMIT(PPC_RAW_ADDIC(_R3, _R3, BPF_TAILCALL_PROLOGUE_SIZE)); + EMIT(PPC_RAW_MTCTR(_R3)); + + EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(BPF_REG_1))); + + /* Put tail_call_cnt in r4 */ + EMIT(PPC_RAW_MR(_R4, _R0)); + + /* tear restore NVRs, ... */ + bpf_jit_emit_common_epilogue(image, ctx); + + EMIT(PPC_RAW_BCTR()); + + /* out: */ + return 0; +} + +/* Assemble the body code between the prologue & epilogue */ +int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct codegen_context *ctx, + u32 *addrs, int pass, bool extra_pass) +{ + const struct bpf_insn *insn = fp->insnsi; + int flen = fp->len; + int i, ret; + + /* Start of epilogue code - will only be valid 2nd pass onwards */ + u32 exit_addr = addrs[flen]; + + for (i = 0; i < flen; i++) { + u32 code = insn[i].code; + u32 prevcode = i ? insn[i - 1].code : 0; + u32 dst_reg = bpf_to_ppc(insn[i].dst_reg); + u32 dst_reg_h = dst_reg - 1; + u32 src_reg = bpf_to_ppc(insn[i].src_reg); + u32 src_reg_h = src_reg - 1; + u32 src2_reg = dst_reg; + u32 src2_reg_h = dst_reg_h; + u32 ax_reg = bpf_to_ppc(BPF_REG_AX); + u32 tmp_reg = bpf_to_ppc(TMP_REG); + u32 size = BPF_SIZE(code); + u32 save_reg, ret_reg; + s16 off = insn[i].off; + s32 imm = insn[i].imm; + bool func_addr_fixed; + u64 func_addr; + u32 true_cond; + u32 tmp_idx; + + if (i && (BPF_CLASS(code) == BPF_ALU64 || BPF_CLASS(code) == BPF_ALU) && + (BPF_CLASS(prevcode) == BPF_ALU64 || BPF_CLASS(prevcode) == BPF_ALU) && + BPF_OP(prevcode) == BPF_MOV && BPF_SRC(prevcode) == BPF_X && + insn[i - 1].dst_reg == insn[i].dst_reg && insn[i - 1].imm != 1) { + src2_reg = bpf_to_ppc(insn[i - 1].src_reg); + src2_reg_h = src2_reg - 1; + ctx->idx = addrs[i - 1] / 4; + } + + /* + * addrs[] maps a BPF bytecode address into a real offset from + * the start of the body code. + */ + addrs[i] = ctx->idx * 4; + + /* + * As an optimization, we note down which registers + * are used so that we can only save/restore those in our + * prologue and epilogue. We do this here regardless of whether + * the actual BPF instruction uses src/dst registers or not + * (for instance, BPF_CALL does not use them). The expectation + * is that those instructions will have src_reg/dst_reg set to + * 0. Even otherwise, we just lose some prologue/epilogue + * optimization but everything else should work without + * any issues. + */ + if (dst_reg >= 3 && dst_reg < 32) { + bpf_set_seen_register(ctx, dst_reg); + bpf_set_seen_register(ctx, dst_reg_h); + } + + if (src_reg >= 3 && src_reg < 32) { + bpf_set_seen_register(ctx, src_reg); + bpf_set_seen_register(ctx, src_reg_h); + } + + switch (code) { + /* + * Arithmetic operations: ADD/SUB/MUL/DIV/MOD/NEG + */ + case BPF_ALU | BPF_ADD | BPF_X: /* (u32) dst += (u32) src */ + EMIT(PPC_RAW_ADD(dst_reg, src2_reg, src_reg)); + break; + case BPF_ALU64 | BPF_ADD | BPF_X: /* dst += src */ + EMIT(PPC_RAW_ADDC(dst_reg, src2_reg, src_reg)); + EMIT(PPC_RAW_ADDE(dst_reg_h, src2_reg_h, src_reg_h)); + break; + case BPF_ALU | BPF_SUB | BPF_X: /* (u32) dst -= (u32) src */ + EMIT(PPC_RAW_SUB(dst_reg, src2_reg, src_reg)); + break; + case BPF_ALU64 | BPF_SUB | BPF_X: /* dst -= src */ + EMIT(PPC_RAW_SUBFC(dst_reg, src_reg, src2_reg)); + EMIT(PPC_RAW_SUBFE(dst_reg_h, src_reg_h, src2_reg_h)); + break; + case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */ + imm = -imm; + fallthrough; + case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */ + if (!imm) { + EMIT(PPC_RAW_MR(dst_reg, src2_reg)); + } else if (IMM_HA(imm) & 0xffff) { + EMIT(PPC_RAW_ADDIS(dst_reg, src2_reg, IMM_HA(imm))); + src2_reg = dst_reg; + } + if (IMM_L(imm)) + EMIT(PPC_RAW_ADDI(dst_reg, src2_reg, IMM_L(imm))); + break; + case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */ + imm = -imm; + fallthrough; + case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */ + if (!imm) { + EMIT(PPC_RAW_MR(dst_reg, src2_reg)); + EMIT(PPC_RAW_MR(dst_reg_h, src2_reg_h)); + break; + } + if (imm >= -32768 && imm < 32768) { + EMIT(PPC_RAW_ADDIC(dst_reg, src2_reg, imm)); + } else { + PPC_LI32(_R0, imm); + EMIT(PPC_RAW_ADDC(dst_reg, src2_reg, _R0)); + } + if (imm >= 0 || (BPF_OP(code) == BPF_SUB && imm == 0x80000000)) + EMIT(PPC_RAW_ADDZE(dst_reg_h, src2_reg_h)); + else + EMIT(PPC_RAW_ADDME(dst_reg_h, src2_reg_h)); + break; + case BPF_ALU64 | BPF_MUL | BPF_X: /* dst *= src */ + bpf_set_seen_register(ctx, tmp_reg); + EMIT(PPC_RAW_MULW(_R0, src2_reg, src_reg_h)); + EMIT(PPC_RAW_MULW(dst_reg_h, src2_reg_h, src_reg)); + EMIT(PPC_RAW_MULHWU(tmp_reg, src2_reg, src_reg)); + EMIT(PPC_RAW_MULW(dst_reg, src2_reg, src_reg)); + EMIT(PPC_RAW_ADD(dst_reg_h, dst_reg_h, _R0)); + EMIT(PPC_RAW_ADD(dst_reg_h, dst_reg_h, tmp_reg)); + break; + case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */ + EMIT(PPC_RAW_MULW(dst_reg, src2_reg, src_reg)); + break; + case BPF_ALU | BPF_MUL | BPF_K: /* (u32) dst *= (u32) imm */ + if (imm == 1) { + EMIT(PPC_RAW_MR(dst_reg, src2_reg)); + } else if (imm == -1) { + EMIT(PPC_RAW_SUBFIC(dst_reg, src2_reg, 0)); + } else if (is_power_of_2((u32)imm)) { + EMIT(PPC_RAW_SLWI(dst_reg, src2_reg, ilog2(imm))); + } else if (imm >= -32768 && imm < 32768) { + EMIT(PPC_RAW_MULI(dst_reg, src2_reg, imm)); + } else { + PPC_LI32(_R0, imm); + EMIT(PPC_RAW_MULW(dst_reg, src2_reg, _R0)); + } + break; + case BPF_ALU64 | BPF_MUL | BPF_K: /* dst *= imm */ + if (!imm) { + PPC_LI32(dst_reg, 0); + PPC_LI32(dst_reg_h, 0); + } else if (imm == 1) { + EMIT(PPC_RAW_MR(dst_reg, src2_reg)); + EMIT(PPC_RAW_MR(dst_reg_h, src2_reg_h)); + } else if (imm == -1) { + EMIT(PPC_RAW_SUBFIC(dst_reg, src2_reg, 0)); + EMIT(PPC_RAW_SUBFZE(dst_reg_h, src2_reg_h)); + } else if (imm > 0 && is_power_of_2(imm)) { + imm = ilog2(imm); + EMIT(PPC_RAW_RLWINM(dst_reg_h, src2_reg_h, imm, 0, 31 - imm)); + EMIT(PPC_RAW_RLWIMI(dst_reg_h, dst_reg, imm, 32 - imm, 31)); + EMIT(PPC_RAW_SLWI(dst_reg, src2_reg, imm)); + } else { + bpf_set_seen_register(ctx, tmp_reg); + PPC_LI32(tmp_reg, imm); + EMIT(PPC_RAW_MULW(dst_reg_h, src2_reg_h, tmp_reg)); + if (imm < 0) + EMIT(PPC_RAW_SUB(dst_reg_h, dst_reg_h, src2_reg)); + EMIT(PPC_RAW_MULHWU(_R0, src2_reg, tmp_reg)); + EMIT(PPC_RAW_MULW(dst_reg, src2_reg, tmp_reg)); + EMIT(PPC_RAW_ADD(dst_reg_h, dst_reg_h, _R0)); + } + break; + case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */ + if (off) + EMIT(PPC_RAW_DIVW(dst_reg, src2_reg, src_reg)); + else + EMIT(PPC_RAW_DIVWU(dst_reg, src2_reg, src_reg)); + break; + case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */ + if (off) + EMIT(PPC_RAW_DIVW(_R0, src2_reg, src_reg)); + else + EMIT(PPC_RAW_DIVWU(_R0, src2_reg, src_reg)); + EMIT(PPC_RAW_MULW(_R0, src_reg, _R0)); + EMIT(PPC_RAW_SUB(dst_reg, src2_reg, _R0)); + break; + case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */ + return -EOPNOTSUPP; + case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */ + return -EOPNOTSUPP; + case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */ + if (!imm) + return -EINVAL; + if (imm == 1) { + EMIT(PPC_RAW_MR(dst_reg, src2_reg)); + } else if (is_power_of_2((u32)imm)) { + if (off) + EMIT(PPC_RAW_SRAWI(dst_reg, src2_reg, ilog2(imm))); + else + EMIT(PPC_RAW_SRWI(dst_reg, src2_reg, ilog2(imm))); + } else { + PPC_LI32(_R0, imm); + if (off) + EMIT(PPC_RAW_DIVW(dst_reg, src2_reg, _R0)); + else + EMIT(PPC_RAW_DIVWU(dst_reg, src2_reg, _R0)); + } + break; + case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */ + if (!imm) + return -EINVAL; + + if (!is_power_of_2((u32)imm)) { + bpf_set_seen_register(ctx, tmp_reg); + PPC_LI32(tmp_reg, imm); + if (off) + EMIT(PPC_RAW_DIVW(_R0, src2_reg, tmp_reg)); + else + EMIT(PPC_RAW_DIVWU(_R0, src2_reg, tmp_reg)); + EMIT(PPC_RAW_MULW(_R0, tmp_reg, _R0)); + EMIT(PPC_RAW_SUB(dst_reg, src2_reg, _R0)); + } else if (imm == 1) { + EMIT(PPC_RAW_LI(dst_reg, 0)); + } else if (off) { + EMIT(PPC_RAW_SRAWI(_R0, src2_reg, ilog2(imm))); + EMIT(PPC_RAW_ADDZE(_R0, _R0)); + EMIT(PPC_RAW_SLWI(_R0, _R0, ilog2(imm))); + EMIT(PPC_RAW_SUB(dst_reg, src2_reg, _R0)); + } else { + imm = ilog2((u32)imm); + EMIT(PPC_RAW_RLWINM(dst_reg, src2_reg, 0, 32 - imm, 31)); + } + break; + case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */ + if (!imm) + return -EINVAL; + if (imm < 0) + imm = -imm; + if (!is_power_of_2(imm)) + return -EOPNOTSUPP; + if (imm == 1) { + EMIT(PPC_RAW_LI(dst_reg, 0)); + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + } else if (off) { + EMIT(PPC_RAW_SRAWI(dst_reg_h, src2_reg_h, 31)); + EMIT(PPC_RAW_XOR(dst_reg, src2_reg, dst_reg_h)); + EMIT(PPC_RAW_SUBFC(dst_reg, dst_reg_h, dst_reg)); + EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 32 - ilog2(imm), 31)); + EMIT(PPC_RAW_XOR(dst_reg, dst_reg, dst_reg_h)); + EMIT(PPC_RAW_SUBFC(dst_reg, dst_reg_h, dst_reg)); + EMIT(PPC_RAW_SUBFE(dst_reg_h, dst_reg_h, dst_reg_h)); + } else { + EMIT(PPC_RAW_RLWINM(dst_reg, src2_reg, 0, 32 - ilog2(imm), 31)); + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + } + break; + case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */ + if (!imm) + return -EINVAL; + if (!is_power_of_2(abs(imm))) + return -EOPNOTSUPP; + + if (imm < 0) { + EMIT(PPC_RAW_SUBFIC(dst_reg, src2_reg, 0)); + EMIT(PPC_RAW_SUBFZE(dst_reg_h, src2_reg_h)); + imm = -imm; + src2_reg = dst_reg; + } + if (imm == 1) { + EMIT(PPC_RAW_MR(dst_reg, src2_reg)); + EMIT(PPC_RAW_MR(dst_reg_h, src2_reg_h)); + } else { + imm = ilog2(imm); + EMIT(PPC_RAW_RLWINM(dst_reg, src2_reg, 32 - imm, imm, 31)); + EMIT(PPC_RAW_RLWIMI(dst_reg, src2_reg_h, 32 - imm, 0, imm - 1)); + EMIT(PPC_RAW_SRAWI(dst_reg_h, src2_reg_h, imm)); + } + break; + case BPF_ALU | BPF_NEG: /* (u32) dst = -dst */ + EMIT(PPC_RAW_NEG(dst_reg, src2_reg)); + break; + case BPF_ALU64 | BPF_NEG: /* dst = -dst */ + EMIT(PPC_RAW_SUBFIC(dst_reg, src2_reg, 0)); + EMIT(PPC_RAW_SUBFZE(dst_reg_h, src2_reg_h)); + break; + + /* + * Logical operations: AND/OR/XOR/[A]LSH/[A]RSH + */ + case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */ + EMIT(PPC_RAW_AND(dst_reg, src2_reg, src_reg)); + EMIT(PPC_RAW_AND(dst_reg_h, src2_reg_h, src_reg_h)); + break; + case BPF_ALU | BPF_AND | BPF_X: /* (u32) dst = dst & src */ + EMIT(PPC_RAW_AND(dst_reg, src2_reg, src_reg)); + break; + case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */ + if (imm >= 0) + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + fallthrough; + case BPF_ALU | BPF_AND | BPF_K: /* (u32) dst = dst & imm */ + if (!IMM_H(imm)) { + EMIT(PPC_RAW_ANDI(dst_reg, src2_reg, IMM_L(imm))); + } else if (!IMM_L(imm)) { + EMIT(PPC_RAW_ANDIS(dst_reg, src2_reg, IMM_H(imm))); + } else if (imm == (((1 << fls(imm)) - 1) ^ ((1 << (ffs(i) - 1)) - 1))) { + EMIT(PPC_RAW_RLWINM(dst_reg, src2_reg, 0, + 32 - fls(imm), 32 - ffs(imm))); + } else { + PPC_LI32(_R0, imm); + EMIT(PPC_RAW_AND(dst_reg, src2_reg, _R0)); + } + break; + case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */ + EMIT(PPC_RAW_OR(dst_reg, src2_reg, src_reg)); + EMIT(PPC_RAW_OR(dst_reg_h, src2_reg_h, src_reg_h)); + break; + case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */ + EMIT(PPC_RAW_OR(dst_reg, src2_reg, src_reg)); + break; + case BPF_ALU64 | BPF_OR | BPF_K:/* dst = dst | imm */ + /* Sign-extended */ + if (imm < 0) + EMIT(PPC_RAW_LI(dst_reg_h, -1)); + fallthrough; + case BPF_ALU | BPF_OR | BPF_K:/* dst = (u32) dst | (u32) imm */ + if (IMM_L(imm)) { + EMIT(PPC_RAW_ORI(dst_reg, src2_reg, IMM_L(imm))); + src2_reg = dst_reg; + } + if (IMM_H(imm)) + EMIT(PPC_RAW_ORIS(dst_reg, src2_reg, IMM_H(imm))); + break; + case BPF_ALU64 | BPF_XOR | BPF_X: /* dst ^= src */ + if (dst_reg == src_reg) { + EMIT(PPC_RAW_LI(dst_reg, 0)); + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + } else { + EMIT(PPC_RAW_XOR(dst_reg, src2_reg, src_reg)); + EMIT(PPC_RAW_XOR(dst_reg_h, src2_reg_h, src_reg_h)); + } + break; + case BPF_ALU | BPF_XOR | BPF_X: /* (u32) dst ^= src */ + if (dst_reg == src_reg) + EMIT(PPC_RAW_LI(dst_reg, 0)); + else + EMIT(PPC_RAW_XOR(dst_reg, src2_reg, src_reg)); + break; + case BPF_ALU64 | BPF_XOR | BPF_K: /* dst ^= imm */ + if (imm < 0) + EMIT(PPC_RAW_NOR(dst_reg_h, src2_reg_h, src2_reg_h)); + fallthrough; + case BPF_ALU | BPF_XOR | BPF_K: /* (u32) dst ^= (u32) imm */ + if (IMM_L(imm)) { + EMIT(PPC_RAW_XORI(dst_reg, src2_reg, IMM_L(imm))); + src2_reg = dst_reg; + } + if (IMM_H(imm)) + EMIT(PPC_RAW_XORIS(dst_reg, src2_reg, IMM_H(imm))); + break; + case BPF_ALU | BPF_LSH | BPF_X: /* (u32) dst <<= (u32) src */ + EMIT(PPC_RAW_SLW(dst_reg, src2_reg, src_reg)); + break; + case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */ + bpf_set_seen_register(ctx, tmp_reg); + EMIT(PPC_RAW_SUBFIC(_R0, src_reg, 32)); + EMIT(PPC_RAW_SLW(dst_reg_h, src2_reg_h, src_reg)); + EMIT(PPC_RAW_ADDI(tmp_reg, src_reg, 32)); + EMIT(PPC_RAW_SRW(_R0, src2_reg, _R0)); + EMIT(PPC_RAW_SLW(tmp_reg, src2_reg, tmp_reg)); + EMIT(PPC_RAW_OR(dst_reg_h, dst_reg_h, _R0)); + EMIT(PPC_RAW_SLW(dst_reg, src2_reg, src_reg)); + EMIT(PPC_RAW_OR(dst_reg_h, dst_reg_h, tmp_reg)); + break; + case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<= (u32) imm */ + if (imm) + EMIT(PPC_RAW_SLWI(dst_reg, src2_reg, imm)); + else + EMIT(PPC_RAW_MR(dst_reg, src2_reg)); + break; + case BPF_ALU64 | BPF_LSH | BPF_K: /* dst <<= imm */ + if (imm < 0) + return -EINVAL; + if (!imm) { + EMIT(PPC_RAW_MR(dst_reg, src2_reg)); + } else if (imm < 32) { + EMIT(PPC_RAW_RLWINM(dst_reg_h, src2_reg_h, imm, 0, 31 - imm)); + EMIT(PPC_RAW_RLWIMI(dst_reg_h, src2_reg, imm, 32 - imm, 31)); + EMIT(PPC_RAW_RLWINM(dst_reg, src2_reg, imm, 0, 31 - imm)); + } else if (imm < 64) { + EMIT(PPC_RAW_RLWINM(dst_reg_h, src2_reg, imm, 0, 31 - imm)); + EMIT(PPC_RAW_LI(dst_reg, 0)); + } else { + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + EMIT(PPC_RAW_LI(dst_reg, 0)); + } + break; + case BPF_ALU | BPF_RSH | BPF_X: /* (u32) dst >>= (u32) src */ + EMIT(PPC_RAW_SRW(dst_reg, src2_reg, src_reg)); + break; + case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */ + bpf_set_seen_register(ctx, tmp_reg); + EMIT(PPC_RAW_SUBFIC(_R0, src_reg, 32)); + EMIT(PPC_RAW_SRW(dst_reg, src2_reg, src_reg)); + EMIT(PPC_RAW_ADDI(tmp_reg, src_reg, 32)); + EMIT(PPC_RAW_SLW(_R0, src2_reg_h, _R0)); + EMIT(PPC_RAW_SRW(tmp_reg, dst_reg_h, tmp_reg)); + EMIT(PPC_RAW_OR(dst_reg, dst_reg, _R0)); + EMIT(PPC_RAW_SRW(dst_reg_h, src2_reg_h, src_reg)); + EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp_reg)); + break; + case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */ + if (imm) + EMIT(PPC_RAW_SRWI(dst_reg, src2_reg, imm)); + else + EMIT(PPC_RAW_MR(dst_reg, src2_reg)); + break; + case BPF_ALU64 | BPF_RSH | BPF_K: /* dst >>= imm */ + if (imm < 0) + return -EINVAL; + if (!imm) { + EMIT(PPC_RAW_MR(dst_reg, src2_reg)); + EMIT(PPC_RAW_MR(dst_reg_h, src2_reg_h)); + } else if (imm < 32) { + EMIT(PPC_RAW_RLWINM(dst_reg, src2_reg, 32 - imm, imm, 31)); + EMIT(PPC_RAW_RLWIMI(dst_reg, src2_reg_h, 32 - imm, 0, imm - 1)); + EMIT(PPC_RAW_RLWINM(dst_reg_h, src2_reg_h, 32 - imm, imm, 31)); + } else if (imm < 64) { + EMIT(PPC_RAW_RLWINM(dst_reg, src2_reg_h, 64 - imm, imm - 32, 31)); + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + } else { + EMIT(PPC_RAW_LI(dst_reg, 0)); + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + } + break; + case BPF_ALU | BPF_ARSH | BPF_X: /* (s32) dst >>= src */ + EMIT(PPC_RAW_SRAW(dst_reg, src2_reg, src_reg)); + break; + case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */ + bpf_set_seen_register(ctx, tmp_reg); + EMIT(PPC_RAW_SUBFIC(_R0, src_reg, 32)); + EMIT(PPC_RAW_SRW(dst_reg, src2_reg, src_reg)); + EMIT(PPC_RAW_SLW(_R0, src2_reg_h, _R0)); + EMIT(PPC_RAW_ADDI(tmp_reg, src_reg, 32)); + EMIT(PPC_RAW_OR(dst_reg, dst_reg, _R0)); + EMIT(PPC_RAW_RLWINM(_R0, tmp_reg, 0, 26, 26)); + EMIT(PPC_RAW_SRAW(tmp_reg, src2_reg_h, tmp_reg)); + EMIT(PPC_RAW_SRAW(dst_reg_h, src2_reg_h, src_reg)); + EMIT(PPC_RAW_SLW(tmp_reg, tmp_reg, _R0)); + EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp_reg)); + break; + case BPF_ALU | BPF_ARSH | BPF_K: /* (s32) dst >>= imm */ + if (imm) + EMIT(PPC_RAW_SRAWI(dst_reg, src2_reg, imm)); + else + EMIT(PPC_RAW_MR(dst_reg, src2_reg)); + break; + case BPF_ALU64 | BPF_ARSH | BPF_K: /* (s64) dst >>= imm */ + if (imm < 0) + return -EINVAL; + if (!imm) { + EMIT(PPC_RAW_MR(dst_reg, src2_reg)); + EMIT(PPC_RAW_MR(dst_reg_h, src2_reg_h)); + } else if (imm < 32) { + EMIT(PPC_RAW_RLWINM(dst_reg, src2_reg, 32 - imm, imm, 31)); + EMIT(PPC_RAW_RLWIMI(dst_reg, src2_reg_h, 32 - imm, 0, imm - 1)); + EMIT(PPC_RAW_SRAWI(dst_reg_h, src2_reg_h, imm)); + } else if (imm < 64) { + EMIT(PPC_RAW_SRAWI(dst_reg, src2_reg_h, imm - 32)); + EMIT(PPC_RAW_SRAWI(dst_reg_h, src2_reg_h, 31)); + } else { + EMIT(PPC_RAW_SRAWI(dst_reg, src2_reg_h, 31)); + EMIT(PPC_RAW_SRAWI(dst_reg_h, src2_reg_h, 31)); + } + break; + + /* + * MOV + */ + case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */ + if (off == 8) { + EMIT(PPC_RAW_EXTSB(dst_reg, src_reg)); + EMIT(PPC_RAW_SRAWI(dst_reg_h, dst_reg, 31)); + } else if (off == 16) { + EMIT(PPC_RAW_EXTSH(dst_reg, src_reg)); + EMIT(PPC_RAW_SRAWI(dst_reg_h, dst_reg, 31)); + } else if (off == 32 && dst_reg == src_reg) { + EMIT(PPC_RAW_SRAWI(dst_reg_h, src_reg, 31)); + } else if (off == 32) { + EMIT(PPC_RAW_MR(dst_reg, src_reg)); + EMIT(PPC_RAW_SRAWI(dst_reg_h, src_reg, 31)); + } else if (dst_reg != src_reg) { + EMIT(PPC_RAW_MR(dst_reg, src_reg)); + EMIT(PPC_RAW_MR(dst_reg_h, src_reg_h)); + } + break; + case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */ + /* special mov32 for zext */ + if (imm == 1) + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + else if (off == 8) + EMIT(PPC_RAW_EXTSB(dst_reg, src_reg)); + else if (off == 16) + EMIT(PPC_RAW_EXTSH(dst_reg, src_reg)); + else if (dst_reg != src_reg) + EMIT(PPC_RAW_MR(dst_reg, src_reg)); + break; + case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */ + PPC_LI32(dst_reg, imm); + PPC_EX32(dst_reg_h, imm); + break; + case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */ + PPC_LI32(dst_reg, imm); + break; + + /* + * BPF_FROM_BE/LE + */ + case BPF_ALU | BPF_END | BPF_FROM_LE: + case BPF_ALU64 | BPF_END | BPF_FROM_LE: + switch (imm) { + case 16: + /* Copy 16 bits to upper part */ + EMIT(PPC_RAW_RLWIMI(dst_reg, src2_reg, 16, 0, 15)); + /* Rotate 8 bits right & mask */ + EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 24, 16, 31)); + break; + case 32: + /* + * Rotate word left by 8 bits: + * 2 bytes are already in their final position + * -- byte 2 and 4 (of bytes 1, 2, 3 and 4) + */ + EMIT(PPC_RAW_RLWINM(_R0, src2_reg, 8, 0, 31)); + /* Rotate 24 bits and insert byte 1 */ + EMIT(PPC_RAW_RLWIMI(_R0, src2_reg, 24, 0, 7)); + /* Rotate 24 bits and insert byte 3 */ + EMIT(PPC_RAW_RLWIMI(_R0, src2_reg, 24, 16, 23)); + EMIT(PPC_RAW_MR(dst_reg, _R0)); + break; + case 64: + bpf_set_seen_register(ctx, tmp_reg); + EMIT(PPC_RAW_RLWINM(tmp_reg, src2_reg, 8, 0, 31)); + EMIT(PPC_RAW_RLWINM(_R0, src2_reg_h, 8, 0, 31)); + /* Rotate 24 bits and insert byte 1 */ + EMIT(PPC_RAW_RLWIMI(tmp_reg, src2_reg, 24, 0, 7)); + EMIT(PPC_RAW_RLWIMI(_R0, src2_reg_h, 24, 0, 7)); + /* Rotate 24 bits and insert byte 3 */ + EMIT(PPC_RAW_RLWIMI(tmp_reg, src2_reg, 24, 16, 23)); + EMIT(PPC_RAW_RLWIMI(_R0, src2_reg_h, 24, 16, 23)); + EMIT(PPC_RAW_MR(dst_reg, _R0)); + EMIT(PPC_RAW_MR(dst_reg_h, tmp_reg)); + break; + } + if (BPF_CLASS(code) == BPF_ALU64 && imm != 64) + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + break; + case BPF_ALU | BPF_END | BPF_FROM_BE: + switch (imm) { + case 16: + /* zero-extend 16 bits into 32 bits */ + EMIT(PPC_RAW_RLWINM(dst_reg, src2_reg, 0, 16, 31)); + break; + case 32: + case 64: + /* nop */ + break; + } + break; + + /* + * BPF_ST NOSPEC (speculation barrier) + */ + case BPF_ST | BPF_NOSPEC: + break; + + /* + * BPF_ST(X) + */ + case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src */ + EMIT(PPC_RAW_STB(src_reg, dst_reg, off)); + break; + case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */ + PPC_LI32(_R0, imm); + EMIT(PPC_RAW_STB(_R0, dst_reg, off)); + break; + case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */ + EMIT(PPC_RAW_STH(src_reg, dst_reg, off)); + break; + case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */ + PPC_LI32(_R0, imm); + EMIT(PPC_RAW_STH(_R0, dst_reg, off)); + break; + case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */ + EMIT(PPC_RAW_STW(src_reg, dst_reg, off)); + break; + case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */ + PPC_LI32(_R0, imm); + EMIT(PPC_RAW_STW(_R0, dst_reg, off)); + break; + case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */ + EMIT(PPC_RAW_STW(src_reg_h, dst_reg, off)); + EMIT(PPC_RAW_STW(src_reg, dst_reg, off + 4)); + break; + case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */ + PPC_LI32(_R0, imm); + EMIT(PPC_RAW_STW(_R0, dst_reg, off + 4)); + PPC_EX32(_R0, imm); + EMIT(PPC_RAW_STW(_R0, dst_reg, off)); + break; + + /* + * BPF_STX ATOMIC (atomic ops) + */ + case BPF_STX | BPF_ATOMIC | BPF_W: + save_reg = _R0; + ret_reg = src_reg; + + bpf_set_seen_register(ctx, tmp_reg); + bpf_set_seen_register(ctx, ax_reg); + + /* Get offset into TMP_REG */ + EMIT(PPC_RAW_LI(tmp_reg, off)); + /* + * Enforce full ordering for operations with BPF_FETCH by emitting a 'sync' + * before and after the operation. + * + * This is a requirement in the Linux Kernel Memory Model. + * See __cmpxchg_u32() in asm/cmpxchg.h as an example. + */ + if ((imm & BPF_FETCH) && IS_ENABLED(CONFIG_SMP)) + EMIT(PPC_RAW_SYNC()); + tmp_idx = ctx->idx * 4; + /* load value from memory into r0 */ + EMIT(PPC_RAW_LWARX(_R0, tmp_reg, dst_reg, 0)); + + /* Save old value in BPF_REG_AX */ + if (imm & BPF_FETCH) + EMIT(PPC_RAW_MR(ax_reg, _R0)); + + switch (imm) { + case BPF_ADD: + case BPF_ADD | BPF_FETCH: + EMIT(PPC_RAW_ADD(_R0, _R0, src_reg)); + break; + case BPF_AND: + case BPF_AND | BPF_FETCH: + EMIT(PPC_RAW_AND(_R0, _R0, src_reg)); + break; + case BPF_OR: + case BPF_OR | BPF_FETCH: + EMIT(PPC_RAW_OR(_R0, _R0, src_reg)); + break; + case BPF_XOR: + case BPF_XOR | BPF_FETCH: + EMIT(PPC_RAW_XOR(_R0, _R0, src_reg)); + break; + case BPF_CMPXCHG: + /* + * Return old value in BPF_REG_0 for BPF_CMPXCHG & + * in src_reg for other cases. + */ + ret_reg = bpf_to_ppc(BPF_REG_0); + + /* Compare with old value in BPF_REG_0 */ + EMIT(PPC_RAW_CMPW(bpf_to_ppc(BPF_REG_0), _R0)); + /* Don't set if different from old value */ + PPC_BCC_SHORT(COND_NE, (ctx->idx + 3) * 4); + fallthrough; + case BPF_XCHG: + save_reg = src_reg; + break; + default: + pr_err_ratelimited("eBPF filter atomic op code %02x (@%d) unsupported\n", + code, i); + return -EOPNOTSUPP; + } + + /* store new value */ + EMIT(PPC_RAW_STWCX(save_reg, tmp_reg, dst_reg)); + /* we're done if this succeeded */ + PPC_BCC_SHORT(COND_NE, tmp_idx); + + /* For the BPF_FETCH variant, get old data into src_reg */ + if (imm & BPF_FETCH) { + /* Emit 'sync' to enforce full ordering */ + if (IS_ENABLED(CONFIG_SMP)) + EMIT(PPC_RAW_SYNC()); + EMIT(PPC_RAW_MR(ret_reg, ax_reg)); + if (!fp->aux->verifier_zext) + EMIT(PPC_RAW_LI(ret_reg - 1, 0)); /* higher 32-bit */ + } + break; + + case BPF_STX | BPF_ATOMIC | BPF_DW: /* *(u64 *)(dst + off) += src */ + return -EOPNOTSUPP; + + /* + * BPF_LDX + */ + case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEMSX | BPF_B: + case BPF_LDX | BPF_PROBE_MEM | BPF_B: + case BPF_LDX | BPF_PROBE_MEMSX | BPF_B: + case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEMSX | BPF_H: + case BPF_LDX | BPF_PROBE_MEM | BPF_H: + case BPF_LDX | BPF_PROBE_MEMSX | BPF_H: + case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEMSX | BPF_W: + case BPF_LDX | BPF_PROBE_MEM | BPF_W: + case BPF_LDX | BPF_PROBE_MEMSX | BPF_W: + case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */ + case BPF_LDX | BPF_PROBE_MEM | BPF_DW: + /* + * As PTR_TO_BTF_ID that uses BPF_PROBE_MEM mode could either be a valid + * kernel pointer or NULL but not a userspace address, execute BPF_PROBE_MEM + * load only if addr is kernel address (see is_kernel_addr()), otherwise + * set dst_reg=0 and move on. + */ + if (BPF_MODE(code) == BPF_PROBE_MEM || BPF_MODE(code) == BPF_PROBE_MEMSX) { + PPC_LI32(_R0, TASK_SIZE - off); + EMIT(PPC_RAW_CMPLW(src_reg, _R0)); + PPC_BCC_SHORT(COND_GT, (ctx->idx + 4) * 4); + EMIT(PPC_RAW_LI(dst_reg, 0)); + /* + * For BPF_DW case, "li reg_h,0" would be needed when + * !fp->aux->verifier_zext. Emit NOP otherwise. + * + * Note that "li reg_h,0" is emitted for BPF_B/H/W case, + * if necessary. So, jump there instead of emitting an + * additional "li reg_h,0" instruction. + */ + if (size == BPF_DW && !fp->aux->verifier_zext) + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + else + EMIT(PPC_RAW_NOP()); + /* + * Need to jump two instructions instead of one for BPF_DW case + * as there are two load instructions for dst_reg_h & dst_reg + * respectively. + */ + if (size == BPF_DW || + (size == BPF_B && BPF_MODE(code) == BPF_PROBE_MEMSX)) + PPC_JMP((ctx->idx + 3) * 4); + else + PPC_JMP((ctx->idx + 2) * 4); + } + + if (BPF_MODE(code) == BPF_MEMSX || BPF_MODE(code) == BPF_PROBE_MEMSX) { + switch (size) { + case BPF_B: + EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); + EMIT(PPC_RAW_EXTSB(dst_reg, dst_reg)); + break; + case BPF_H: + EMIT(PPC_RAW_LHA(dst_reg, src_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off)); + break; + } + if (!fp->aux->verifier_zext) + EMIT(PPC_RAW_SRAWI(dst_reg_h, dst_reg, 31)); + + } else { + switch (size) { + case BPF_B: + EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); + break; + case BPF_H: + EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off)); + break; + case BPF_DW: + EMIT(PPC_RAW_LWZ(dst_reg_h, src_reg, off)); + EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off + 4)); + break; + } + if (size != BPF_DW && !fp->aux->verifier_zext) + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + } + + if (BPF_MODE(code) == BPF_PROBE_MEM) { + int insn_idx = ctx->idx - 1; + int jmp_off = 4; + + /* + * In case of BPF_DW, two lwz instructions are emitted, one + * for higher 32-bit and another for lower 32-bit. So, set + * ex->insn to the first of the two and jump over both + * instructions in fixup. + * + * Similarly, with !verifier_zext, two instructions are + * emitted for BPF_B/H/W case. So, set ex->insn to the + * instruction that could fault and skip over both + * instructions. + */ + if (size == BPF_DW || !fp->aux->verifier_zext) { + insn_idx -= 1; + jmp_off += 4; + } + + ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx, insn_idx, + jmp_off, dst_reg, code); + if (ret) + return ret; + } + break; + + /* + * Doubleword load + * 16 byte instruction that uses two 'struct bpf_insn' + */ + case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */ + PPC_LI32(dst_reg_h, (u32)insn[i + 1].imm); + PPC_LI32(dst_reg, (u32)insn[i].imm); + /* Adjust for two bpf instructions */ + addrs[++i] = ctx->idx * 4; + break; + + /* + * Return/Exit + */ + case BPF_JMP | BPF_EXIT: + /* + * If this isn't the very last instruction, branch to + * the epilogue. If we _are_ the last instruction, + * we'll just fall through to the epilogue. + */ + if (i != flen - 1) { + ret = bpf_jit_emit_exit_insn(image, ctx, _R0, exit_addr); + if (ret) + return ret; + } + /* else fall through to the epilogue */ + break; + + /* + * Call kernel helper or bpf function + */ + case BPF_JMP | BPF_CALL: + ctx->seen |= SEEN_FUNC; + + ret = bpf_jit_get_func_addr(fp, &insn[i], extra_pass, + &func_addr, &func_addr_fixed); + if (ret < 0) + return ret; + + if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_5))) { + EMIT(PPC_RAW_STW(bpf_to_ppc(BPF_REG_5) - 1, _R1, 8)); + EMIT(PPC_RAW_STW(bpf_to_ppc(BPF_REG_5), _R1, 12)); + } + + ret = bpf_jit_emit_func_call_rel(image, fimage, ctx, func_addr); + if (ret) + return ret; + + EMIT(PPC_RAW_MR(bpf_to_ppc(BPF_REG_0) - 1, _R3)); + EMIT(PPC_RAW_MR(bpf_to_ppc(BPF_REG_0), _R4)); + break; + + /* + * Jumps and branches + */ + case BPF_JMP | BPF_JA: + PPC_JMP(addrs[i + 1 + off]); + break; + case BPF_JMP32 | BPF_JA: + PPC_JMP(addrs[i + 1 + imm]); + break; + + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JSGT | BPF_K: + case BPF_JMP | BPF_JSGT | BPF_X: + case BPF_JMP32 | BPF_JGT | BPF_K: + case BPF_JMP32 | BPF_JGT | BPF_X: + case BPF_JMP32 | BPF_JSGT | BPF_K: + case BPF_JMP32 | BPF_JSGT | BPF_X: + true_cond = COND_GT; + goto cond_branch; + case BPF_JMP | BPF_JLT | BPF_K: + case BPF_JMP | BPF_JLT | BPF_X: + case BPF_JMP | BPF_JSLT | BPF_K: + case BPF_JMP | BPF_JSLT | BPF_X: + case BPF_JMP32 | BPF_JLT | BPF_K: + case BPF_JMP32 | BPF_JLT | BPF_X: + case BPF_JMP32 | BPF_JSLT | BPF_K: + case BPF_JMP32 | BPF_JSLT | BPF_X: + true_cond = COND_LT; + goto cond_branch; + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JSGE | BPF_K: + case BPF_JMP | BPF_JSGE | BPF_X: + case BPF_JMP32 | BPF_JGE | BPF_K: + case BPF_JMP32 | BPF_JGE | BPF_X: + case BPF_JMP32 | BPF_JSGE | BPF_K: + case BPF_JMP32 | BPF_JSGE | BPF_X: + true_cond = COND_GE; + goto cond_branch; + case BPF_JMP | BPF_JLE | BPF_K: + case BPF_JMP | BPF_JLE | BPF_X: + case BPF_JMP | BPF_JSLE | BPF_K: + case BPF_JMP | BPF_JSLE | BPF_X: + case BPF_JMP32 | BPF_JLE | BPF_K: + case BPF_JMP32 | BPF_JLE | BPF_X: + case BPF_JMP32 | BPF_JSLE | BPF_K: + case BPF_JMP32 | BPF_JSLE | BPF_X: + true_cond = COND_LE; + goto cond_branch; + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP32 | BPF_JEQ | BPF_K: + case BPF_JMP32 | BPF_JEQ | BPF_X: + true_cond = COND_EQ; + goto cond_branch; + case BPF_JMP | BPF_JNE | BPF_K: + case BPF_JMP | BPF_JNE | BPF_X: + case BPF_JMP32 | BPF_JNE | BPF_K: + case BPF_JMP32 | BPF_JNE | BPF_X: + true_cond = COND_NE; + goto cond_branch; + case BPF_JMP | BPF_JSET | BPF_K: + case BPF_JMP | BPF_JSET | BPF_X: + case BPF_JMP32 | BPF_JSET | BPF_K: + case BPF_JMP32 | BPF_JSET | BPF_X: + true_cond = COND_NE; + /* fallthrough; */ + +cond_branch: + switch (code) { + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JLT | BPF_X: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JLE | BPF_X: + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP | BPF_JNE | BPF_X: + /* unsigned comparison */ + EMIT(PPC_RAW_CMPLW(dst_reg_h, src_reg_h)); + PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4); + EMIT(PPC_RAW_CMPLW(dst_reg, src_reg)); + break; + case BPF_JMP32 | BPF_JGT | BPF_X: + case BPF_JMP32 | BPF_JLT | BPF_X: + case BPF_JMP32 | BPF_JGE | BPF_X: + case BPF_JMP32 | BPF_JLE | BPF_X: + case BPF_JMP32 | BPF_JEQ | BPF_X: + case BPF_JMP32 | BPF_JNE | BPF_X: + /* unsigned comparison */ + EMIT(PPC_RAW_CMPLW(dst_reg, src_reg)); + break; + case BPF_JMP | BPF_JSGT | BPF_X: + case BPF_JMP | BPF_JSLT | BPF_X: + case BPF_JMP | BPF_JSGE | BPF_X: + case BPF_JMP | BPF_JSLE | BPF_X: + /* signed comparison */ + EMIT(PPC_RAW_CMPW(dst_reg_h, src_reg_h)); + PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4); + EMIT(PPC_RAW_CMPLW(dst_reg, src_reg)); + break; + case BPF_JMP32 | BPF_JSGT | BPF_X: + case BPF_JMP32 | BPF_JSLT | BPF_X: + case BPF_JMP32 | BPF_JSGE | BPF_X: + case BPF_JMP32 | BPF_JSLE | BPF_X: + /* signed comparison */ + EMIT(PPC_RAW_CMPW(dst_reg, src_reg)); + break; + case BPF_JMP | BPF_JSET | BPF_X: + EMIT(PPC_RAW_AND_DOT(_R0, dst_reg_h, src_reg_h)); + PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4); + EMIT(PPC_RAW_AND_DOT(_R0, dst_reg, src_reg)); + break; + case BPF_JMP32 | BPF_JSET | BPF_X: { + EMIT(PPC_RAW_AND_DOT(_R0, dst_reg, src_reg)); + break; + case BPF_JMP | BPF_JNE | BPF_K: + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JLT | BPF_K: + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JLE | BPF_K: + /* + * Need sign-extended load, so only positive + * values can be used as imm in cmplwi + */ + if (imm >= 0 && imm < 32768) { + EMIT(PPC_RAW_CMPLWI(dst_reg_h, 0)); + PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4); + EMIT(PPC_RAW_CMPLWI(dst_reg, imm)); + } else { + /* sign-extending load ... but unsigned comparison */ + PPC_EX32(_R0, imm); + EMIT(PPC_RAW_CMPLW(dst_reg_h, _R0)); + PPC_LI32(_R0, imm); + PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4); + EMIT(PPC_RAW_CMPLW(dst_reg, _R0)); + } + break; + case BPF_JMP32 | BPF_JNE | BPF_K: + case BPF_JMP32 | BPF_JEQ | BPF_K: + case BPF_JMP32 | BPF_JGT | BPF_K: + case BPF_JMP32 | BPF_JLT | BPF_K: + case BPF_JMP32 | BPF_JGE | BPF_K: + case BPF_JMP32 | BPF_JLE | BPF_K: + if (imm >= 0 && imm < 65536) { + EMIT(PPC_RAW_CMPLWI(dst_reg, imm)); + } else { + PPC_LI32(_R0, imm); + EMIT(PPC_RAW_CMPLW(dst_reg, _R0)); + } + break; + } + case BPF_JMP | BPF_JSGT | BPF_K: + case BPF_JMP | BPF_JSLT | BPF_K: + case BPF_JMP | BPF_JSGE | BPF_K: + case BPF_JMP | BPF_JSLE | BPF_K: + if (imm >= 0 && imm < 65536) { + EMIT(PPC_RAW_CMPWI(dst_reg_h, imm < 0 ? -1 : 0)); + PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4); + EMIT(PPC_RAW_CMPLWI(dst_reg, imm)); + } else { + /* sign-extending load */ + EMIT(PPC_RAW_CMPWI(dst_reg_h, imm < 0 ? -1 : 0)); + PPC_LI32(_R0, imm); + PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4); + EMIT(PPC_RAW_CMPLW(dst_reg, _R0)); + } + break; + case BPF_JMP32 | BPF_JSGT | BPF_K: + case BPF_JMP32 | BPF_JSLT | BPF_K: + case BPF_JMP32 | BPF_JSGE | BPF_K: + case BPF_JMP32 | BPF_JSLE | BPF_K: + /* + * signed comparison, so any 16-bit value + * can be used in cmpwi + */ + if (imm >= -32768 && imm < 32768) { + EMIT(PPC_RAW_CMPWI(dst_reg, imm)); + } else { + /* sign-extending load */ + PPC_LI32(_R0, imm); + EMIT(PPC_RAW_CMPW(dst_reg, _R0)); + } + break; + case BPF_JMP | BPF_JSET | BPF_K: + /* andi does not sign-extend the immediate */ + if (imm >= 0 && imm < 32768) { + /* PPC_ANDI is _only/always_ dot-form */ + EMIT(PPC_RAW_ANDI(_R0, dst_reg, imm)); + } else { + PPC_LI32(_R0, imm); + if (imm < 0) { + EMIT(PPC_RAW_CMPWI(dst_reg_h, 0)); + PPC_BCC_SHORT(COND_NE, (ctx->idx + 2) * 4); + } + EMIT(PPC_RAW_AND_DOT(_R0, dst_reg, _R0)); + } + break; + case BPF_JMP32 | BPF_JSET | BPF_K: + /* andi does not sign-extend the immediate */ + if (imm >= 0 && imm < 32768) { + /* PPC_ANDI is _only/always_ dot-form */ + EMIT(PPC_RAW_ANDI(_R0, dst_reg, imm)); + } else { + PPC_LI32(_R0, imm); + EMIT(PPC_RAW_AND_DOT(_R0, dst_reg, _R0)); + } + break; + } + PPC_BCC(true_cond, addrs[i + 1 + off]); + break; + + /* + * Tail call + */ + case BPF_JMP | BPF_TAIL_CALL: + ctx->seen |= SEEN_TAILCALL; + ret = bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]); + if (ret < 0) + return ret; + break; + + default: + /* + * The filter contains something cruel & unusual. + * We don't handle it, but also there shouldn't be + * anything missing from our list. + */ + pr_err_ratelimited("eBPF filter opcode %04x (@%d) unsupported\n", code, i); + return -EOPNOTSUPP; + } + if (BPF_CLASS(code) == BPF_ALU && !fp->aux->verifier_zext && + !insn_is_zext(&insn[i + 1]) && !(BPF_OP(code) == BPF_END && imm == 64)) + EMIT(PPC_RAW_LI(dst_reg_h, 0)); + } + + /* Set end-of-body-code address for exit. */ + addrs[i] = ctx->idx * 4; + + return 0; +} diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c new file mode 100644 index 000000000..fc9db691e --- /dev/null +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -0,0 +1,2036 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * bpf_jit_comp64.c: eBPF JIT compiler + * + * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> + * IBM Corporation + * + * Based on the powerpc classic BPF JIT compiler by Matt Evans + */ +#include <linux/moduleloader.h> +#include <asm/cacheflush.h> +#include <asm/asm-compat.h> +#include <linux/netdevice.h> +#include <linux/filter.h> +#include <linux/if_vlan.h> +#include <asm/kprobes.h> +#include <linux/bpf.h> +#include <asm/security_features.h> + +#include "bpf_jit.h" + +/* + * Stack layout with frame: + * Layout when setting up our own stack frame. + * Note: r1 at bottom, component offsets positive wrt r1. + * Ensure the top half (upto local_tmp_var) stays consistent + * with our redzone usage. + * + * tail_call_info - stores tailcall count value in main program's + * frame, stores reference to tail_call_info of + * main's frame in sub-prog's frame. + * + * [ prev sp ] <------------- + * [ tail_call_info ] 8 | + * [ nv gpr save area ] (6 * 8) | + * [ addl. nv gpr save area] (12 * 8) | <--- exception boundary/callback program + * [ local_tmp_var ] 24 | + * fp (r31) --> [ ebpf stack space ] upto 512 | + * [ frame header ] 32/112 | + * sp (r1) ---> [ stack pointer ] -------------- + * + * Additional (12 * 8) in 'nv gpr save area' only in case of + * exception boundary/callback. + */ + +/* BPF non-volatile registers save area size */ +#define BPF_PPC_STACK_SAVE (6 * 8) + +/* for bpf JIT code internal usage */ +#define BPF_PPC_STACK_LOCALS 24 +/* + * for additional non volatile registers(r14-r25) to be saved + * at exception boundary + */ +#define BPF_PPC_EXC_STACK_SAVE (12 * 8) + +/* stack frame excluding BPF stack, ensure this is quadword aligned */ +#define BPF_PPC_STACKFRAME (STACK_FRAME_MIN_SIZE + \ + BPF_PPC_STACK_LOCALS + \ + BPF_PPC_STACK_SAVE + \ + BPF_PPC_TAILCALL) + +/* + * same as BPF_PPC_STACKFRAME with save area for additional + * non volatile registers saved at exception boundary. + * This is quad-word aligned. + */ +#define BPF_PPC_EXC_STACKFRAME (BPF_PPC_STACKFRAME + BPF_PPC_EXC_STACK_SAVE) + +/* BPF register usage */ +#define TMP_REG_1 (MAX_BPF_JIT_REG + 0) +#define TMP_REG_2 (MAX_BPF_JIT_REG + 1) +#define ARENA_VM_START (MAX_BPF_JIT_REG + 2) + +/* BPF to ppc register mappings */ +void bpf_jit_init_reg_mapping(struct codegen_context *ctx) +{ + /* function return value */ + ctx->b2p[BPF_REG_0] = _R8; + /* function arguments */ + ctx->b2p[BPF_REG_1] = _R3; + ctx->b2p[BPF_REG_2] = _R4; + ctx->b2p[BPF_REG_3] = _R5; + ctx->b2p[BPF_REG_4] = _R6; + ctx->b2p[BPF_REG_5] = _R7; + /* non volatile registers */ + ctx->b2p[BPF_REG_6] = _R27; + ctx->b2p[BPF_REG_7] = _R28; + ctx->b2p[BPF_REG_8] = _R29; + ctx->b2p[BPF_REG_9] = _R30; + /* frame pointer aka BPF_REG_10 */ + ctx->b2p[BPF_REG_FP] = _R31; + /* eBPF jit internal registers */ + ctx->b2p[BPF_REG_AX] = _R12; + ctx->b2p[TMP_REG_1] = _R9; + ctx->b2p[TMP_REG_2] = _R10; + /* non volatile register for kern_vm_start address */ + ctx->b2p[ARENA_VM_START] = _R26; +} + +/* PPC NVR range -- update this if we ever use NVRs below r26 */ +#define BPF_PPC_NVR_MIN _R26 + +static inline bool bpf_has_stack_frame(struct codegen_context *ctx) +{ + /* + * We only need a stack frame if: + * - we call other functions (kernel helpers), or + * - the bpf program uses its stack area + * The latter condition is deduced from the usage of BPF_REG_FP + * + * bpf_throw() leads to exception callback from a BPF (sub)program. + * The (sub)program is always marked as SEEN_FUNC, creating a stack + * frame. The exception callback uses the frame of the exception + * boundary, so the exception boundary program must have a frame. + */ + return ctx->seen & SEEN_FUNC || + bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP)) || + ctx->exception_cb || + ctx->exception_boundary; +} + +/* + * Stack layout with redzone: + * When not setting up our own stackframe, the redzone (288 bytes) usage is: + * Note: r1 from prev frame. Component offset negative wrt r1. + * + * [ prev sp ] <------------- + * [ ... ] | + * sp (r1) ---> [ stack pointer ] -------------- + * [ tail_call_info ] 8 + * [ nv gpr save area ] (6 * 8) + * [ addl. nv gpr save area] (12 * 8) <--- exception boundary/callback program + * [ local_tmp_var ] 24 + * [ unused red zone ] 224 + * + * Additional (12 * 8) in 'nv gpr save area' only in case of + * exception boundary/callback. + */ +static int bpf_jit_stack_local(struct codegen_context *ctx) +{ + if (bpf_has_stack_frame(ctx)) { + /* Stack layout with frame */ + return STACK_FRAME_MIN_SIZE + ctx->stack_size; + } else { + /* Stack layout with redzone */ + return -(BPF_PPC_TAILCALL + +BPF_PPC_STACK_SAVE + +(ctx->exception_boundary || ctx->exception_cb ? + BPF_PPC_EXC_STACK_SAVE : 0) + +BPF_PPC_STACK_LOCALS + ); + } +} + +static int bpf_jit_stack_tailcallinfo_offset(struct codegen_context *ctx) +{ + return bpf_jit_stack_local(ctx) + BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE; +} + +static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg) +{ + int min_valid_nvreg = BPF_PPC_NVR_MIN; + /* Default frame size for all cases except exception boundary */ + int frame_nvr_size = BPF_PPC_STACKFRAME; + + /* Consider all nv regs for handling exceptions */ + if (ctx->exception_boundary || ctx->exception_cb) { + min_valid_nvreg = _R14; + frame_nvr_size = BPF_PPC_EXC_STACKFRAME; + } + + if (reg >= min_valid_nvreg && reg < 32) + return (bpf_has_stack_frame(ctx) ? + (frame_nvr_size + ctx->stack_size) : 0) + - (8 * (32 - reg)) - BPF_PPC_TAILCALL; + + pr_err("BPF JIT is asking about unknown registers"); + BUG(); +} + +void prepare_for_fsession_fentry(u32 *image, struct codegen_context *ctx, int cookie_cnt, + int cookie_off, int retval_off) +{ + EMIT(PPC_RAW_LI(bpf_to_ppc(TMP_REG_1), 0)); + + for (int i = 0; i < cookie_cnt; i++) + EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, cookie_off + 8 * i)); + EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, retval_off)); +} + +void store_func_meta(u32 *image, struct codegen_context *ctx, + u64 func_meta, int func_meta_off) +{ + /* + * Store func_meta to stack at [R1 + func_meta_off] = func_meta + * + * func_meta : + * bit[63]: is_return flag + * byte[1]: cookie offset from ctx + * byte[0]: args count + */ + PPC_LI64(bpf_to_ppc(TMP_REG_1), func_meta); + EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, func_meta_off)); +} + +void bpf_jit_realloc_regs(struct codegen_context *ctx) +{ +} + +static void emit_fp_priv_stack(u32 *image, struct codegen_context *ctx) +{ + PPC_LI64(bpf_to_ppc(BPF_REG_FP), (__force long)ctx->priv_sp); + /* + * Load base percpu pointer of private stack allocation. + * Runtime per-cpu address = (base + data_offset) + (guard + stack_size) + */ +#ifdef CONFIG_SMP + /* Load percpu data offset */ + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), _R13, + offsetof(struct paca_struct, data_offset))); + EMIT(PPC_RAW_ADD(bpf_to_ppc(BPF_REG_FP), + bpf_to_ppc(TMP_REG_1), bpf_to_ppc(BPF_REG_FP))); +#endif + EMIT(PPC_RAW_ADDI(bpf_to_ppc(BPF_REG_FP), bpf_to_ppc(BPF_REG_FP), + PRIV_STACK_GUARD_SZ + round_up(ctx->priv_stack_size, 16))); +} + +/* + * For exception boundary & exception_cb progs: + * return increased size to accommodate additional NVRs. + */ +static int bpf_jit_stack_size(struct codegen_context *ctx) +{ + return ctx->exception_boundary || ctx->exception_cb ? + BPF_PPC_EXC_STACKFRAME : + BPF_PPC_STACKFRAME; +} + +void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx) +{ + int i; + + /* Instruction for trampoline attach */ + EMIT(PPC_RAW_NOP()); + +#ifndef CONFIG_PPC_KERNEL_PCREL + if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2)) + EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc))); +#endif + + /* + * Tail call count(tcc) is saved & updated only in main + * program's frame and the address of tcc in main program's + * frame (tcc_ptr) is saved in subprogs frame. + * + * Offset of tail_call_info on any frame will be interpreted + * as either tcc_ptr or tcc value depending on whether it is + * greater than MAX_TAIL_CALL_CNT or not. + */ + if (!ctx->is_subprog) { + EMIT(PPC_RAW_LI(bpf_to_ppc(TMP_REG_1), 0)); + /* this goes in the redzone */ + EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, -(BPF_PPC_TAILCALL))); + } else if (!ctx->exception_cb) { + /* + * Tailcall jitting for non exception_cb progs only. + * exception_cb won't require tail_call_info to be setup. + * + * tail_call_info interpretation logic: + * + * if tail_call_info < MAX_TAIL_CALL_CNT + * main prog calling first subprog -> copy reference + * else + * subsequent subprog calling another subprog -> directly copy content + */ + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_2), _R1, 0)); + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_2), -(BPF_PPC_TAILCALL))); + EMIT(PPC_RAW_CMPLWI(bpf_to_ppc(TMP_REG_1), MAX_TAIL_CALL_CNT)); + PPC_BCC_CONST_SHORT(COND_GT, 8); + EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_2), + -(BPF_PPC_TAILCALL))); + EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, -(BPF_PPC_TAILCALL))); + } + + if (bpf_has_stack_frame(ctx) && !ctx->exception_cb) { + /* + * We need a stack frame, but we don't necessarily need to + * save/restore LR unless we call other functions + */ + if (ctx->seen & SEEN_FUNC) { + EMIT(PPC_RAW_MFLR(_R0)); + EMIT(PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF)); + } + + EMIT(PPC_RAW_STDU(_R1, _R1, + -(bpf_jit_stack_size(ctx) + ctx->stack_size))); + } + + /* + * Program acting as exception boundary pushes R14..R25 in addition to + * BPF callee-saved non volatile registers. Exception callback uses + * the boundary program's stack frame, recover additionally saved + * registers in epilogue of exception callback. + */ + if (ctx->exception_boundary) { + for (i = _R14; i <= _R25; i++) + EMIT(PPC_RAW_STD(i, _R1, bpf_jit_stack_offsetof(ctx, i))); + } + + if (!ctx->exception_cb) { + /* + * Back up non-volatile regs -- BPF registers 6-10 + * If we haven't created our own stack frame, we save these + * in the protected zone below the previous stack frame + */ + for (i = BPF_REG_6; i <= BPF_REG_10; i++) + if (ctx->exception_boundary || bpf_is_seen_register(ctx, bpf_to_ppc(i))) + EMIT(PPC_RAW_STD(bpf_to_ppc(i), _R1, + bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i)))); + + if (ctx->exception_boundary || ctx->arena_vm_start) + EMIT(PPC_RAW_STD(bpf_to_ppc(ARENA_VM_START), _R1, + bpf_jit_stack_offsetof(ctx, bpf_to_ppc(ARENA_VM_START)))); + } else { + /* + * Exception callback receives Frame Pointer of boundary + * program(main prog) as third arg + */ + EMIT(PPC_RAW_MR(_R1, _R5)); + /* + * Exception callback reuses the stack frame of exception boundary. + * But BPF stack depth of exception callback and exception boundary + * don't have to be same. If BPF stack depth is different, adjust the + * stack frame size considering BPF stack depth of exception callback. + * The non-volatile register save area remains unchanged. These non- + * volatile registers are restored in exception callback's epilogue. + */ + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), _R5, 0)); + EMIT(PPC_RAW_SUB(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_1), _R1)); + EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_2), + -BPF_PPC_EXC_STACKFRAME)); + EMIT(PPC_RAW_CMPLDI(bpf_to_ppc(TMP_REG_2), ctx->stack_size)); + PPC_BCC_CONST_SHORT(COND_EQ, 12); + EMIT(PPC_RAW_MR(_R1, bpf_to_ppc(TMP_REG_1))); + EMIT(PPC_RAW_STDU(_R1, _R1, -(BPF_PPC_EXC_STACKFRAME + ctx->stack_size))); + } + + /* + * Exception_cb not restricted from using stack area or arena. + * Setup frame pointer to point to the bpf stack area + */ + if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP))) { + if (ctx->priv_sp) { + /* Set up fp in private stack */ + emit_fp_priv_stack(image, ctx); + } else { + /* Setup frame pointer to point to the bpf stack area */ + EMIT(PPC_RAW_ADDI(bpf_to_ppc(BPF_REG_FP), _R1, + STACK_FRAME_MIN_SIZE + ctx->stack_size)); + } + } + + if (ctx->arena_vm_start) + PPC_LI64(bpf_to_ppc(ARENA_VM_START), ctx->arena_vm_start); +} + +static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx) +{ + int i; + + /* Restore NVRs */ + for (i = BPF_REG_6; i <= BPF_REG_10; i++) + if (ctx->exception_cb || bpf_is_seen_register(ctx, bpf_to_ppc(i))) + EMIT(PPC_RAW_LD(bpf_to_ppc(i), _R1, bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i)))); + + if (ctx->exception_cb || ctx->arena_vm_start) + EMIT(PPC_RAW_LD(bpf_to_ppc(ARENA_VM_START), _R1, + bpf_jit_stack_offsetof(ctx, bpf_to_ppc(ARENA_VM_START)))); + + if (ctx->exception_cb) { + /* + * Recover additionally saved non volatile registers from stack + * frame of exception boundary program. + */ + for (i = _R14; i <= _R25; i++) + EMIT(PPC_RAW_LD(i, _R1, bpf_jit_stack_offsetof(ctx, i))); + } + + /* Tear down our stack frame */ + if (bpf_has_stack_frame(ctx)) { + EMIT(PPC_RAW_ADDI(_R1, _R1, bpf_jit_stack_size(ctx) + ctx->stack_size)); + + if (ctx->seen & SEEN_FUNC || ctx->exception_cb) { + EMIT(PPC_RAW_LD(_R0, _R1, PPC_LR_STKOFF)); + EMIT(PPC_RAW_MTLR(_R0)); + } + } +} + +void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) +{ + bpf_jit_emit_common_epilogue(image, ctx); + + /* Move result to r3 */ + EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(BPF_REG_0))); + + EMIT(PPC_RAW_BLR()); + + bpf_jit_build_fentry_stubs(image, ctx); +} + +/* + * arch_bpf_stack_walk() - BPF stack walker for PowerPC + * + * Based on arch_stack_walk() from stacktrace.c. + * PowerPC uses stack frames rather than stack pointers. See [1] for + * the equivalence between frame pointers and stack pointers. + * Additional reference at [2]. + * TODO: refactor with arch_stack_walk() + * + * [1]: https://lore.kernel.org/all/20200220115141.2707-1-mpe@ellerman.id.au/ + * [2]: https://lore.kernel.org/bpf/20260122211854.5508-5-adubey@linux.ibm.com/ + */ + +void arch_bpf_stack_walk(bool (*consume_fn)(void *, u64, u64, u64), void *cookie) +{ + // callback processing always in current context + unsigned long sp = current_stack_frame(); + + for (;;) { + unsigned long *stack = (unsigned long *) sp; + unsigned long ip; + + if (!validate_sp(sp, current)) + return; + + ip = stack[STACK_FRAME_LR_SAVE]; + if (!ip) + break; + + /* + * consume_fn common code expects stack pointer in third + * argument. There is no sp in ppc64, rather pass frame + * pointer(named sp here). + */ + if (ip && !consume_fn(cookie, ip, sp, sp)) + break; + + sp = stack[0]; + } +} + +static int bpf_jit_emit_func_call(u32 *image, struct codegen_context *ctx, u64 func_addr, int reg) +{ + long reladdr = func_addr - kernel_toc_addr(); + + if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) { + pr_err("eBPF: address of %ps out of range of kernel_toc.\n", (void *)func_addr); + return -ERANGE; + } + + EMIT(PPC_RAW_ADDIS(reg, _R2, PPC_HA(reladdr))); + EMIT(PPC_RAW_ADDI(reg, reg, PPC_LO(reladdr))); + EMIT(PPC_RAW_MTCTR(reg)); + EMIT(PPC_RAW_BCTRL()); + + return 0; +} + +int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, struct codegen_context *ctx, u64 func) +{ + unsigned long func_addr = func ? ppc_function_entry((void *)func) : 0; + + /* bpf to bpf call, func is not known in the initial pass. Emit 5 nops as a placeholder */ + if (!func) { + for (int i = 0; i < 5; i++) + EMIT(PPC_RAW_NOP()); + /* elfv1 needs an additional instruction to load addr from descriptor */ + if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1)) + EMIT(PPC_RAW_NOP()); + EMIT(PPC_RAW_MTCTR(_R12)); + EMIT(PPC_RAW_BCTRL()); + return 0; + } + +#ifdef CONFIG_PPC_KERNEL_PCREL + long reladdr; + + reladdr = func_addr - local_paca->kernelbase; + + /* + * If fimage is NULL (the initial pass to find image size), + * account for the maximum no. of instructions possible. + */ + if (!fimage) { + ctx->idx += 7; + return 0; + } else if (reladdr < (long)SZ_8G && reladdr >= -(long)SZ_8G) { + EMIT(PPC_RAW_LD(_R12, _R13, offsetof(struct paca_struct, kernelbase))); + /* Align for subsequent prefix instruction */ + if (!IS_ALIGNED((unsigned long)fimage + CTX_NIA(ctx), 8)) + EMIT(PPC_RAW_NOP()); + /* paddi r12,r12,addr */ + EMIT(PPC_PREFIX_MLS | __PPC_PRFX_R(0) | IMM_H18(reladdr)); + EMIT(PPC_INST_PADDI | ___PPC_RT(_R12) | ___PPC_RA(_R12) | IMM_L(reladdr)); + } else { + unsigned long pc = (unsigned long)fimage + CTX_NIA(ctx); + bool alignment_needed = !IS_ALIGNED(pc, 8); + + reladdr = func_addr - (alignment_needed ? pc + 4 : pc); + + if (reladdr < (long)SZ_8G && reladdr >= -(long)SZ_8G) { + if (alignment_needed) + EMIT(PPC_RAW_NOP()); + /* pla r12,addr */ + EMIT(PPC_PREFIX_MLS | __PPC_PRFX_R(1) | IMM_H18(reladdr)); + EMIT(PPC_INST_PADDI | ___PPC_RT(_R12) | IMM_L(reladdr)); + } else { + /* We can clobber r12 */ + PPC_LI64(_R12, func); + } + } + EMIT(PPC_RAW_MTCTR(_R12)); + EMIT(PPC_RAW_BCTRL()); +#else + if (core_kernel_text(func_addr)) { + int ret = bpf_jit_emit_func_call(image, ctx, func_addr, _R12); + if (ret) + return ret; + } else { + if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1)) { + /* func points to the function descriptor */ + PPC_LI64(bpf_to_ppc(TMP_REG_2), func); + /* Load actual entry point from function descriptor */ + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_2), 0)); + /* ... and move it to CTR */ + EMIT(PPC_RAW_MTCTR(bpf_to_ppc(TMP_REG_1))); + /* + * Load TOC from function descriptor at offset 8. + * We can clobber r2 since we get called through a + * function pointer (so caller will save/restore r2). + */ + if (is_module_text_address(func_addr)) + EMIT(PPC_RAW_LD(_R2, bpf_to_ppc(TMP_REG_2), 8)); + } else { + PPC_LI64(_R12, func); + EMIT(PPC_RAW_MTCTR(_R12)); + } + EMIT(PPC_RAW_BCTRL()); + /* + * Load r2 with kernel TOC as kernel TOC is used if function address falls + * within core kernel text. + */ + if (is_module_text_address(func_addr)) + EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc))); + } +#endif + + return 0; +} + +static int zero_extend(u32 *image, struct codegen_context *ctx, u32 src_reg, u32 dst_reg, u32 size) +{ + switch (size) { + case 1: + /* zero-extend 8 bits into 64 bits */ + EMIT(PPC_RAW_RLDICL(dst_reg, src_reg, 0, 56)); + return 0; + case 2: + /* zero-extend 16 bits into 64 bits */ + EMIT(PPC_RAW_RLDICL(dst_reg, src_reg, 0, 48)); + return 0; + case 4: + /* zero-extend 32 bits into 64 bits */ + EMIT(PPC_RAW_RLDICL(dst_reg, src_reg, 0, 32)); + fallthrough; + case 8: + /* Nothing to do */ + return 0; + default: + return -1; + } +} + +static int sign_extend(u32 *image, struct codegen_context *ctx, u32 src_reg, u32 dst_reg, u32 size) +{ + switch (size) { + case 1: + /* sign-extend 8 bits into 64 bits */ + EMIT(PPC_RAW_EXTSB(dst_reg, src_reg)); + return 0; + case 2: + /* sign-extend 16 bits into 64 bits */ + EMIT(PPC_RAW_EXTSH(dst_reg, src_reg)); + return 0; + case 4: + /* sign-extend 32 bits into 64 bits */ + EMIT(PPC_RAW_EXTSW(dst_reg, src_reg)); + fallthrough; + case 8: + /* Nothing to do */ + return 0; + default: + return -1; + } +} + +/* + * Handle powerpc ABI expectations from caller: + * - Unsigned arguments are zero-extended. + * - Signed arguments are sign-extended. + */ +static int prepare_for_kfunc_call(const struct bpf_prog *fp, u32 *image, + struct codegen_context *ctx, + const struct bpf_insn *insn) +{ + const struct btf_func_model *m = bpf_jit_find_kfunc_model(fp, insn); + int i; + + if (!m) + return -1; + + for (i = 0; i < m->nr_args; i++) { + /* Note that BPF ABI only allows up to 5 args for kfuncs */ + u32 reg = bpf_to_ppc(BPF_REG_1 + i), size = m->arg_size[i]; + + if (!(m->arg_flags[i] & BTF_FMODEL_SIGNED_ARG)) { + if (zero_extend(image, ctx, reg, reg, size)) + return -1; + } else { + if (sign_extend(image, ctx, reg, reg, size)) + return -1; + } + } + + return 0; +} + +static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out) +{ + /* + * By now, the eBPF program has already setup parameters in r3, r4 and r5 + * r3/BPF_REG_1 - pointer to ctx -- passed as is to the next bpf program + * r4/BPF_REG_2 - pointer to bpf_array + * r5/BPF_REG_3 - index in bpf_array + */ + int b2p_bpf_array = bpf_to_ppc(BPF_REG_2); + int b2p_index = bpf_to_ppc(BPF_REG_3); + int bpf_tailcall_prologue_size = 12; + + if (!IS_ENABLED(CONFIG_PPC_KERNEL_PCREL) && IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2)) + bpf_tailcall_prologue_size += 4; /* skip past the toc load */ + + /* + * if (index >= array->map.max_entries) + * goto out; + */ + EMIT(PPC_RAW_LWZ(bpf_to_ppc(TMP_REG_1), b2p_bpf_array, offsetof(struct bpf_array, map.max_entries))); + EMIT(PPC_RAW_RLWINM(b2p_index, b2p_index, 0, 0, 31)); + EMIT(PPC_RAW_CMPLW(b2p_index, bpf_to_ppc(TMP_REG_1))); + PPC_BCC_SHORT(COND_GE, out); + + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), _R1, bpf_jit_stack_tailcallinfo_offset(ctx))); + EMIT(PPC_RAW_CMPLWI(bpf_to_ppc(TMP_REG_1), MAX_TAIL_CALL_CNT)); + PPC_BCC_CONST_SHORT(COND_LE, 8); + + /* dereference TMP_REG_1 */ + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), 0)); + + /* + * if (tail_call_info == MAX_TAIL_CALL_CNT) + * goto out; + */ + EMIT(PPC_RAW_CMPLWI(bpf_to_ppc(TMP_REG_1), MAX_TAIL_CALL_CNT)); + PPC_BCC_SHORT(COND_EQ, out); + + /* + * tail_call_info++; <- Actual value of tcc here + * Writeback this updated value only if tailcall succeeds. + */ + EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), 1)); + + /* prog = array->ptrs[index]; */ + EMIT(PPC_RAW_MULI(bpf_to_ppc(TMP_REG_2), b2p_index, 8)); + EMIT(PPC_RAW_ADD(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_2), b2p_bpf_array)); + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_2), + offsetof(struct bpf_array, ptrs))); + + /* + * if (prog == NULL) + * goto out; + */ + EMIT(PPC_RAW_CMPLDI(bpf_to_ppc(TMP_REG_2), 0)); + PPC_BCC_SHORT(COND_EQ, out); + + /* goto *(prog->bpf_func + prologue_size); */ + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_2), + offsetof(struct bpf_prog, bpf_func))); + EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_2), + FUNCTION_DESCR_SIZE + bpf_tailcall_prologue_size)); + EMIT(PPC_RAW_MTCTR(bpf_to_ppc(TMP_REG_2))); + + /* + * Before writing updated tail_call_info, distinguish if current frame + * is storing a reference to tail_call_info or actual tcc value in + * tail_call_info. + */ + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_2), _R1, bpf_jit_stack_tailcallinfo_offset(ctx))); + EMIT(PPC_RAW_CMPLWI(bpf_to_ppc(TMP_REG_2), MAX_TAIL_CALL_CNT)); + PPC_BCC_CONST_SHORT(COND_GT, 8); + + /* First get address of tail_call_info */ + EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_2), _R1, bpf_jit_stack_tailcallinfo_offset(ctx))); + /* Writeback updated value to tail_call_info */ + EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_2), 0)); + + /* tear down stack, restore NVRs, ... */ + bpf_jit_emit_common_epilogue(image, ctx); + + EMIT(PPC_RAW_BCTR()); + + /* out: */ + return 0; +} + +bool bpf_jit_bypass_spec_v1(void) +{ +#if defined(CONFIG_PPC_E500) || defined(CONFIG_PPC_BOOK3S_64) + return !(security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && + security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR)); +#else + return true; +#endif +} + +bool bpf_jit_bypass_spec_v4(void) +{ + return !(security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && + security_ftr_enabled(SEC_FTR_STF_BARRIER) && + stf_barrier_type_get() != STF_BARRIER_NONE); +} + +/* + * We spill into the redzone always, even if the bpf program has its own stackframe. + * Offsets hardcoded based on BPF_PPC_STACK_SAVE -- see bpf_jit_stack_local() + */ +void bpf_stf_barrier(void); + +asm ( +" .global bpf_stf_barrier ;" +" bpf_stf_barrier: ;" +" std 21,-80(1) ;" +" std 22,-72(1) ;" +" sync ;" +" ld 21,-80(1) ;" +" ld 22,-72(1) ;" +" ori 31,31,0 ;" +" .rept 14 ;" +" b 1f ;" +" 1: ;" +" .endr ;" +" blr ;" +); + +static int bpf_jit_emit_atomic_ops(u32 *image, struct codegen_context *ctx, + const struct bpf_insn *insn, u32 *jmp_off, + u32 *tmp_idx, u32 *addrp) +{ + u32 tmp1_reg = bpf_to_ppc(TMP_REG_1); + u32 tmp2_reg = bpf_to_ppc(TMP_REG_2); + u32 size = BPF_SIZE(insn->code); + u32 src_reg = bpf_to_ppc(insn->src_reg); + u32 dst_reg = bpf_to_ppc(insn->dst_reg); + s32 imm = insn->imm; + + u32 save_reg = tmp2_reg; + u32 ret_reg = src_reg; + u32 fixup_idx; + + /* Get offset into TMP_REG_1 */ + EMIT(PPC_RAW_LI(tmp1_reg, insn->off)); + /* + * Enforce full ordering for operations with BPF_FETCH by emitting a 'sync' + * before and after the operation. + * + * This is a requirement in the Linux Kernel Memory Model. + * See __cmpxchg_u64() in asm/cmpxchg.h as an example. + */ + if ((imm & BPF_FETCH) && IS_ENABLED(CONFIG_SMP)) + EMIT(PPC_RAW_SYNC()); + + *tmp_idx = ctx->idx; + + /* load value from memory into TMP_REG_2 */ + if (size == BPF_DW) + EMIT(PPC_RAW_LDARX(tmp2_reg, tmp1_reg, dst_reg, 0)); + else + EMIT(PPC_RAW_LWARX(tmp2_reg, tmp1_reg, dst_reg, 0)); + /* Save old value in _R0 */ + if (imm & BPF_FETCH) + EMIT(PPC_RAW_MR(_R0, tmp2_reg)); + + switch (imm) { + case BPF_ADD: + case BPF_ADD | BPF_FETCH: + EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg)); + break; + case BPF_AND: + case BPF_AND | BPF_FETCH: + EMIT(PPC_RAW_AND(tmp2_reg, tmp2_reg, src_reg)); + break; + case BPF_OR: + case BPF_OR | BPF_FETCH: + EMIT(PPC_RAW_OR(tmp2_reg, tmp2_reg, src_reg)); + break; + case BPF_XOR: + case BPF_XOR | BPF_FETCH: + EMIT(PPC_RAW_XOR(tmp2_reg, tmp2_reg, src_reg)); + break; + case BPF_CMPXCHG: + /* + * Return old value in BPF_REG_0 for BPF_CMPXCHG & + * in src_reg for other cases. + */ + ret_reg = bpf_to_ppc(BPF_REG_0); + + /* Compare with old value in BPF_R0 */ + if (size == BPF_DW) + EMIT(PPC_RAW_CMPD(bpf_to_ppc(BPF_REG_0), tmp2_reg)); + else + EMIT(PPC_RAW_CMPW(bpf_to_ppc(BPF_REG_0), tmp2_reg)); + /* Don't set if different from old value */ + PPC_BCC_SHORT(COND_NE, (ctx->idx + 3) * 4); + fallthrough; + case BPF_XCHG: + save_reg = src_reg; + break; + default: + return -EOPNOTSUPP; + } + + /* store new value */ + if (size == BPF_DW) + EMIT(PPC_RAW_STDCX(save_reg, tmp1_reg, dst_reg)); + else + EMIT(PPC_RAW_STWCX(save_reg, tmp1_reg, dst_reg)); + /* we're done if this succeeded */ + PPC_BCC_SHORT(COND_NE, *tmp_idx * 4); + fixup_idx = ctx->idx; + + if (imm & BPF_FETCH) { + /* Emit 'sync' to enforce full ordering */ + if (IS_ENABLED(CONFIG_SMP)) + EMIT(PPC_RAW_SYNC()); + EMIT(PPC_RAW_MR(ret_reg, _R0)); + /* + * Skip unnecessary zero-extension for 32-bit cmpxchg. + * For context, see commit 39491867ace5. + */ + if (size != BPF_DW && imm == BPF_CMPXCHG && + insn_is_zext(insn + 1)) + *addrp = ctx->idx * 4; + } + + *jmp_off = (fixup_idx - *tmp_idx) * 4; + + return 0; +} + +static int bpf_jit_emit_probe_mem_store(struct codegen_context *ctx, u32 src_reg, s16 off, + u32 code, u32 *image) +{ + u32 tmp1_reg = bpf_to_ppc(TMP_REG_1); + u32 tmp2_reg = bpf_to_ppc(TMP_REG_2); + + switch (BPF_SIZE(code)) { + case BPF_B: + EMIT(PPC_RAW_STB(src_reg, tmp1_reg, off)); + break; + case BPF_H: + EMIT(PPC_RAW_STH(src_reg, tmp1_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_STW(src_reg, tmp1_reg, off)); + break; + case BPF_DW: + if (off % 4) { + EMIT(PPC_RAW_LI(tmp2_reg, off)); + EMIT(PPC_RAW_STDX(src_reg, tmp1_reg, tmp2_reg)); + } else { + EMIT(PPC_RAW_STD(src_reg, tmp1_reg, off)); + } + break; + default: + return -EINVAL; + } + return 0; +} + +static int emit_atomic_ld_st(const struct bpf_insn insn, struct codegen_context *ctx, u32 *image) +{ + u32 code = insn.code; + u32 dst_reg = bpf_to_ppc(insn.dst_reg); + u32 src_reg = bpf_to_ppc(insn.src_reg); + u32 size = BPF_SIZE(code); + u32 tmp1_reg = bpf_to_ppc(TMP_REG_1); + u32 tmp2_reg = bpf_to_ppc(TMP_REG_2); + s16 off = insn.off; + s32 imm = insn.imm; + + switch (imm) { + case BPF_LOAD_ACQ: + switch (size) { + case BPF_B: + EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); + break; + case BPF_H: + EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off)); + break; + case BPF_DW: + if (off % 4) { + EMIT(PPC_RAW_LI(tmp1_reg, off)); + EMIT(PPC_RAW_LDX(dst_reg, src_reg, tmp1_reg)); + } else { + EMIT(PPC_RAW_LD(dst_reg, src_reg, off)); + } + break; + } + EMIT(PPC_RAW_LWSYNC()); + break; + case BPF_STORE_REL: + EMIT(PPC_RAW_LWSYNC()); + switch (size) { + case BPF_B: + EMIT(PPC_RAW_STB(src_reg, dst_reg, off)); + break; + case BPF_H: + EMIT(PPC_RAW_STH(src_reg, dst_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_STW(src_reg, dst_reg, off)); + break; + case BPF_DW: + if (off % 4) { + EMIT(PPC_RAW_LI(tmp2_reg, off)); + EMIT(PPC_RAW_STDX(src_reg, dst_reg, tmp2_reg)); + } else { + EMIT(PPC_RAW_STD(src_reg, dst_reg, off)); + } + break; + } + break; + default: + pr_err_ratelimited("unexpected atomic load/store op code %02x\n", + imm); + return -EINVAL; + } + + return 0; +} + +/* Assemble the body code between the prologue & epilogue */ +int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct codegen_context *ctx, + u32 *addrs, int pass, bool extra_pass) +{ + enum stf_barrier_type stf_barrier = stf_barrier_type_get(); + bool sync_emitted, ori31_emitted; + const struct bpf_insn *insn = fp->insnsi; + int flen = fp->len; + int i, ret; + + /* Start of epilogue code - will only be valid 2nd pass onwards */ + u32 exit_addr = addrs[flen]; + + for (i = 0; i < flen; i++) { + u32 code = insn[i].code; + u32 dst_reg = bpf_to_ppc(insn[i].dst_reg); + u32 src_reg = bpf_to_ppc(insn[i].src_reg); + u32 size = BPF_SIZE(code); + u32 tmp1_reg = bpf_to_ppc(TMP_REG_1); + u32 tmp2_reg = bpf_to_ppc(TMP_REG_2); + s16 off = insn[i].off; + s32 imm = insn[i].imm; + bool func_addr_fixed; + u64 func_addr; + u64 imm64; + u32 true_cond; + u32 tmp_idx; + u32 jmp_off; + + /* + * addrs[] maps a BPF bytecode address into a real offset from + * the start of the body code. + */ + addrs[i] = ctx->idx * 4; + + /* + * As an optimization, we note down which non-volatile registers + * are used so that we can only save/restore those in our + * prologue and epilogue. We do this here regardless of whether + * the actual BPF instruction uses src/dst registers or not + * (for instance, BPF_CALL does not use them). The expectation + * is that those instructions will have src_reg/dst_reg set to + * 0. Even otherwise, we just lose some prologue/epilogue + * optimization but everything else should work without + * any issues. + */ + if (dst_reg >= BPF_PPC_NVR_MIN && dst_reg < 32) + bpf_set_seen_register(ctx, dst_reg); + if (src_reg >= BPF_PPC_NVR_MIN && src_reg < 32) + bpf_set_seen_register(ctx, src_reg); + + switch (code) { + /* + * Arithmetic operations: ADD/SUB/MUL/DIV/MOD/NEG + */ + case BPF_ALU | BPF_ADD | BPF_X: /* (u32) dst += (u32) src */ + case BPF_ALU64 | BPF_ADD | BPF_X: /* dst += src */ + EMIT(PPC_RAW_ADD(dst_reg, dst_reg, src_reg)); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_SUB | BPF_X: /* (u32) dst -= (u32) src */ + case BPF_ALU64 | BPF_SUB | BPF_X: /* dst -= src */ + EMIT(PPC_RAW_SUB(dst_reg, dst_reg, src_reg)); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */ + case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */ + if (!imm) { + goto bpf_alu32_trunc; + } else if (imm >= -32768 && imm < 32768) { + EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(imm))); + } else { + PPC_LI32(tmp1_reg, imm); + EMIT(PPC_RAW_ADD(dst_reg, dst_reg, tmp1_reg)); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */ + case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */ + if (!imm) { + goto bpf_alu32_trunc; + } else if (imm > -32768 && imm <= 32768) { + EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(-imm))); + } else { + PPC_LI32(tmp1_reg, imm); + EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg)); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */ + case BPF_ALU64 | BPF_MUL | BPF_X: /* dst *= src */ + if (BPF_CLASS(code) == BPF_ALU) + EMIT(PPC_RAW_MULW(dst_reg, dst_reg, src_reg)); + else + EMIT(PPC_RAW_MULD(dst_reg, dst_reg, src_reg)); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_MUL | BPF_K: /* (u32) dst *= (u32) imm */ + case BPF_ALU64 | BPF_MUL | BPF_K: /* dst *= imm */ + if (imm >= -32768 && imm < 32768) + EMIT(PPC_RAW_MULI(dst_reg, dst_reg, IMM_L(imm))); + else { + PPC_LI32(tmp1_reg, imm); + if (BPF_CLASS(code) == BPF_ALU) + EMIT(PPC_RAW_MULW(dst_reg, dst_reg, tmp1_reg)); + else + EMIT(PPC_RAW_MULD(dst_reg, dst_reg, tmp1_reg)); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */ + case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */ + if (BPF_OP(code) == BPF_MOD) { + if (off) + EMIT(PPC_RAW_DIVW(tmp1_reg, dst_reg, src_reg)); + else + EMIT(PPC_RAW_DIVWU(tmp1_reg, dst_reg, src_reg)); + + EMIT(PPC_RAW_MULW(tmp1_reg, src_reg, tmp1_reg)); + EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg)); + } else + if (off) + EMIT(PPC_RAW_DIVW(dst_reg, dst_reg, src_reg)); + else + EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, src_reg)); + goto bpf_alu32_trunc; + case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */ + case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */ + if (BPF_OP(code) == BPF_MOD) { + if (off) + EMIT(PPC_RAW_DIVD(tmp1_reg, dst_reg, src_reg)); + else + EMIT(PPC_RAW_DIVDU(tmp1_reg, dst_reg, src_reg)); + EMIT(PPC_RAW_MULD(tmp1_reg, src_reg, tmp1_reg)); + EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg)); + } else + if (off) + EMIT(PPC_RAW_DIVD(dst_reg, dst_reg, src_reg)); + else + EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, src_reg)); + break; + case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */ + case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */ + case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */ + case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */ + if (imm == 0) + return -EINVAL; + if (imm == 1) { + if (BPF_OP(code) == BPF_DIV) { + goto bpf_alu32_trunc; + } else { + EMIT(PPC_RAW_LI(dst_reg, 0)); + break; + } + } + + PPC_LI32(tmp1_reg, imm); + switch (BPF_CLASS(code)) { + case BPF_ALU: + if (BPF_OP(code) == BPF_MOD) { + if (off) + EMIT(PPC_RAW_DIVW(tmp2_reg, dst_reg, tmp1_reg)); + else + EMIT(PPC_RAW_DIVWU(tmp2_reg, dst_reg, tmp1_reg)); + EMIT(PPC_RAW_MULW(tmp1_reg, tmp1_reg, tmp2_reg)); + EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg)); + } else + if (off) + EMIT(PPC_RAW_DIVW(dst_reg, dst_reg, tmp1_reg)); + else + EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, tmp1_reg)); + break; + case BPF_ALU64: + if (BPF_OP(code) == BPF_MOD) { + if (off) + EMIT(PPC_RAW_DIVD(tmp2_reg, dst_reg, tmp1_reg)); + else + EMIT(PPC_RAW_DIVDU(tmp2_reg, dst_reg, tmp1_reg)); + EMIT(PPC_RAW_MULD(tmp1_reg, tmp1_reg, tmp2_reg)); + EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg)); + } else + if (off) + EMIT(PPC_RAW_DIVD(dst_reg, dst_reg, tmp1_reg)); + else + EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, tmp1_reg)); + break; + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_NEG: /* (u32) dst = -dst */ + case BPF_ALU64 | BPF_NEG: /* dst = -dst */ + EMIT(PPC_RAW_NEG(dst_reg, dst_reg)); + goto bpf_alu32_trunc; + + /* + * Logical operations: AND/OR/XOR/[A]LSH/[A]RSH + */ + case BPF_ALU | BPF_AND | BPF_X: /* (u32) dst = dst & src */ + case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */ + EMIT(PPC_RAW_AND(dst_reg, dst_reg, src_reg)); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_AND | BPF_K: /* (u32) dst = dst & imm */ + case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */ + if (!IMM_H(imm)) + EMIT(PPC_RAW_ANDI(dst_reg, dst_reg, IMM_L(imm))); + else { + /* Sign-extended */ + PPC_LI32(tmp1_reg, imm); + EMIT(PPC_RAW_AND(dst_reg, dst_reg, tmp1_reg)); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */ + case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */ + EMIT(PPC_RAW_OR(dst_reg, dst_reg, src_reg)); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_OR | BPF_K:/* dst = (u32) dst | (u32) imm */ + case BPF_ALU64 | BPF_OR | BPF_K:/* dst = dst | imm */ + if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) { + /* Sign-extended */ + PPC_LI32(tmp1_reg, imm); + EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp1_reg)); + } else { + if (IMM_L(imm)) + EMIT(PPC_RAW_ORI(dst_reg, dst_reg, IMM_L(imm))); + if (IMM_H(imm)) + EMIT(PPC_RAW_ORIS(dst_reg, dst_reg, IMM_H(imm))); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_XOR | BPF_X: /* (u32) dst ^= src */ + case BPF_ALU64 | BPF_XOR | BPF_X: /* dst ^= src */ + EMIT(PPC_RAW_XOR(dst_reg, dst_reg, src_reg)); + goto bpf_alu32_trunc; + case BPF_ALU | BPF_XOR | BPF_K: /* (u32) dst ^= (u32) imm */ + case BPF_ALU64 | BPF_XOR | BPF_K: /* dst ^= imm */ + if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) { + /* Sign-extended */ + PPC_LI32(tmp1_reg, imm); + EMIT(PPC_RAW_XOR(dst_reg, dst_reg, tmp1_reg)); + } else { + if (IMM_L(imm)) + EMIT(PPC_RAW_XORI(dst_reg, dst_reg, IMM_L(imm))); + if (IMM_H(imm)) + EMIT(PPC_RAW_XORIS(dst_reg, dst_reg, IMM_H(imm))); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_LSH | BPF_X: /* (u32) dst <<= (u32) src */ + /* slw clears top 32 bits */ + EMIT(PPC_RAW_SLW(dst_reg, dst_reg, src_reg)); + /* skip zero extension move, but set address map. */ + if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; + break; + case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */ + EMIT(PPC_RAW_SLD(dst_reg, dst_reg, src_reg)); + break; + case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<== (u32) imm */ + /* with imm 0, we still need to clear top 32 bits */ + EMIT(PPC_RAW_SLWI(dst_reg, dst_reg, imm)); + if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; + break; + case BPF_ALU64 | BPF_LSH | BPF_K: /* dst <<== imm */ + if (imm != 0) + EMIT(PPC_RAW_SLDI(dst_reg, dst_reg, imm)); + break; + case BPF_ALU | BPF_RSH | BPF_X: /* (u32) dst >>= (u32) src */ + EMIT(PPC_RAW_SRW(dst_reg, dst_reg, src_reg)); + if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; + break; + case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */ + EMIT(PPC_RAW_SRD(dst_reg, dst_reg, src_reg)); + break; + case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */ + EMIT(PPC_RAW_SRWI(dst_reg, dst_reg, imm)); + if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; + break; + case BPF_ALU64 | BPF_RSH | BPF_K: /* dst >>= imm */ + if (imm != 0) + EMIT(PPC_RAW_SRDI(dst_reg, dst_reg, imm)); + break; + case BPF_ALU | BPF_ARSH | BPF_X: /* (s32) dst >>= src */ + EMIT(PPC_RAW_SRAW(dst_reg, dst_reg, src_reg)); + goto bpf_alu32_trunc; + case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */ + EMIT(PPC_RAW_SRAD(dst_reg, dst_reg, src_reg)); + break; + case BPF_ALU | BPF_ARSH | BPF_K: /* (s32) dst >>= imm */ + EMIT(PPC_RAW_SRAWI(dst_reg, dst_reg, imm)); + goto bpf_alu32_trunc; + case BPF_ALU64 | BPF_ARSH | BPF_K: /* (s64) dst >>= imm */ + if (imm != 0) + EMIT(PPC_RAW_SRADI(dst_reg, dst_reg, imm)); + break; + + /* + * MOV + */ + case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */ + case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */ + + if (insn_is_mov_percpu_addr(&insn[i])) { + if (IS_ENABLED(CONFIG_SMP)) { + EMIT(PPC_RAW_LD(tmp1_reg, _R13, offsetof(struct paca_struct, data_offset))); + EMIT(PPC_RAW_ADD(dst_reg, src_reg, tmp1_reg)); + } else if (src_reg != dst_reg) { + EMIT(PPC_RAW_MR(dst_reg, src_reg)); + } + break; + } + + if (insn_is_cast_user(&insn[i])) { + EMIT(PPC_RAW_RLDICL_DOT(tmp1_reg, src_reg, 0, 32)); + PPC_LI64(dst_reg, (ctx->user_vm_start & 0xffffffff00000000UL)); + PPC_BCC_SHORT(COND_EQ, (ctx->idx + 2) * 4); + EMIT(PPC_RAW_OR(tmp1_reg, dst_reg, tmp1_reg)); + EMIT(PPC_RAW_MR(dst_reg, tmp1_reg)); + break; + } + + if (imm == 1) { + /* special mov32 for zext */ + EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31)); + break; + } + if (off == 0) { + /* MOV */ + if (dst_reg != src_reg) + EMIT(PPC_RAW_MR(dst_reg, src_reg)); + } else { + /* MOVSX: dst = (s8,s16,s32)src (off = 8,16,32) */ + if (sign_extend(image, ctx, src_reg, dst_reg, off / 8)) + return -1; + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */ + case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */ + PPC_LI32(dst_reg, imm); + if (imm < 0) + goto bpf_alu32_trunc; + else if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; + break; + +bpf_alu32_trunc: + /* Truncate to 32-bits */ + if (BPF_CLASS(code) == BPF_ALU && !fp->aux->verifier_zext) + EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31)); + break; + + /* + * BPF_FROM_BE/LE + */ + case BPF_ALU | BPF_END | BPF_FROM_LE: + case BPF_ALU | BPF_END | BPF_FROM_BE: + case BPF_ALU64 | BPF_END | BPF_FROM_LE: +#ifdef __BIG_ENDIAN__ + if (BPF_SRC(code) == BPF_FROM_BE) + goto emit_clear; +#else /* !__BIG_ENDIAN__ */ + if (BPF_CLASS(code) == BPF_ALU && BPF_SRC(code) == BPF_FROM_LE) + goto emit_clear; +#endif + switch (imm) { + case 16: + /* Rotate 8 bits left & mask with 0x0000ff00 */ + EMIT(PPC_RAW_RLWINM(tmp1_reg, dst_reg, 8, 16, 23)); + /* Rotate 8 bits right & insert LSB to reg */ + EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 24, 31)); + /* Move result back to dst_reg */ + EMIT(PPC_RAW_MR(dst_reg, tmp1_reg)); + break; + case 32: + /* + * Rotate word left by 8 bits: + * 2 bytes are already in their final position + * -- byte 2 and 4 (of bytes 1, 2, 3 and 4) + */ + EMIT(PPC_RAW_RLWINM(tmp1_reg, dst_reg, 8, 0, 31)); + /* Rotate 24 bits and insert byte 1 */ + EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 0, 7)); + /* Rotate 24 bits and insert byte 3 */ + EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 16, 23)); + EMIT(PPC_RAW_MR(dst_reg, tmp1_reg)); + break; + case 64: + /* Store the value to stack and then use byte-reverse loads */ + EMIT(PPC_RAW_STD(dst_reg, _R1, bpf_jit_stack_local(ctx))); + EMIT(PPC_RAW_ADDI(tmp1_reg, _R1, bpf_jit_stack_local(ctx))); + if (cpu_has_feature(CPU_FTR_ARCH_206)) { + EMIT(PPC_RAW_LDBRX(dst_reg, 0, tmp1_reg)); + } else { + EMIT(PPC_RAW_LWBRX(dst_reg, 0, tmp1_reg)); + if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN)) + EMIT(PPC_RAW_SLDI(dst_reg, dst_reg, 32)); + EMIT(PPC_RAW_LI(tmp2_reg, 4)); + EMIT(PPC_RAW_LWBRX(tmp2_reg, tmp2_reg, tmp1_reg)); + if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) + EMIT(PPC_RAW_SLDI(tmp2_reg, tmp2_reg, 32)); + EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp2_reg)); + } + break; + } + break; + +emit_clear: + switch (imm) { + case 16: + /* zero-extend 16 bits into 64 bits */ + EMIT(PPC_RAW_RLDICL(dst_reg, dst_reg, 0, 48)); + if (insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; + break; + case 32: + if (!fp->aux->verifier_zext) + /* zero-extend 32 bits into 64 bits */ + EMIT(PPC_RAW_RLDICL(dst_reg, dst_reg, 0, 32)); + break; + case 64: + /* nop */ + break; + } + break; + + /* + * BPF_ST NOSPEC (speculation barrier) + * + * The following must act as a barrier against both Spectre v1 + * and v4 if we requested both mitigations. Therefore, also emit + * 'isync; sync' on E500 or 'ori31' on BOOK3S_64 in addition to + * the insns needed for a Spectre v4 barrier. + * + * If we requested only !bypass_spec_v1 OR only !bypass_spec_v4, + * we can skip the respective other barrier type as an + * optimization. + */ + case BPF_ST | BPF_NOSPEC: + sync_emitted = false; + ori31_emitted = false; + if (IS_ENABLED(CONFIG_PPC_E500) && + !bpf_jit_bypass_spec_v1()) { + EMIT(PPC_RAW_ISYNC()); + EMIT(PPC_RAW_SYNC()); + sync_emitted = true; + } + if (!bpf_jit_bypass_spec_v4()) { + switch (stf_barrier) { + case STF_BARRIER_EIEIO: + EMIT(PPC_RAW_EIEIO() | 0x02000000); + break; + case STF_BARRIER_SYNC_ORI: + if (!sync_emitted) + EMIT(PPC_RAW_SYNC()); + EMIT(PPC_RAW_LD(tmp1_reg, _R13, 0)); + EMIT(PPC_RAW_ORI(_R31, _R31, 0)); + ori31_emitted = true; + break; + case STF_BARRIER_FALLBACK: + ctx->seen |= SEEN_FUNC; + PPC_LI64(_R12, dereference_kernel_function_descriptor(bpf_stf_barrier)); + EMIT(PPC_RAW_MTCTR(_R12)); + EMIT(PPC_RAW_BCTRL()); + break; + case STF_BARRIER_NONE: + break; + } + } + if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && + !bpf_jit_bypass_spec_v1() && + !ori31_emitted) + EMIT(PPC_RAW_ORI(_R31, _R31, 0)); + break; + + /* + * BPF_ST(X) + */ + case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src */ + case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */ + if (BPF_CLASS(code) == BPF_ST) { + EMIT(PPC_RAW_LI(tmp1_reg, imm)); + src_reg = tmp1_reg; + } + EMIT(PPC_RAW_STB(src_reg, dst_reg, off)); + break; + case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */ + case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */ + if (BPF_CLASS(code) == BPF_ST) { + EMIT(PPC_RAW_LI(tmp1_reg, imm)); + src_reg = tmp1_reg; + } + EMIT(PPC_RAW_STH(src_reg, dst_reg, off)); + break; + case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */ + case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */ + if (BPF_CLASS(code) == BPF_ST) { + PPC_LI32(tmp1_reg, imm); + src_reg = tmp1_reg; + } + EMIT(PPC_RAW_STW(src_reg, dst_reg, off)); + break; + case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */ + case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */ + if (BPF_CLASS(code) == BPF_ST) { + PPC_LI32(tmp1_reg, imm); + src_reg = tmp1_reg; + } + if (off % 4) { + EMIT(PPC_RAW_LI(tmp2_reg, off)); + EMIT(PPC_RAW_STDX(src_reg, dst_reg, tmp2_reg)); + } else { + EMIT(PPC_RAW_STD(src_reg, dst_reg, off)); + } + break; + + case BPF_STX | BPF_PROBE_MEM32 | BPF_B: + case BPF_STX | BPF_PROBE_MEM32 | BPF_H: + case BPF_STX | BPF_PROBE_MEM32 | BPF_W: + case BPF_STX | BPF_PROBE_MEM32 | BPF_DW: + + EMIT(PPC_RAW_ADD(tmp1_reg, dst_reg, bpf_to_ppc(ARENA_VM_START))); + + ret = bpf_jit_emit_probe_mem_store(ctx, src_reg, off, code, image); + if (ret) + return ret; + + ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx, + ctx->idx - 1, 4, -1, code); + if (ret) + return ret; + + break; + + case BPF_ST | BPF_PROBE_MEM32 | BPF_B: + case BPF_ST | BPF_PROBE_MEM32 | BPF_H: + case BPF_ST | BPF_PROBE_MEM32 | BPF_W: + case BPF_ST | BPF_PROBE_MEM32 | BPF_DW: + + EMIT(PPC_RAW_ADD(tmp1_reg, dst_reg, bpf_to_ppc(ARENA_VM_START))); + + if (BPF_SIZE(code) == BPF_W || BPF_SIZE(code) == BPF_DW) { + PPC_LI32(tmp2_reg, imm); + src_reg = tmp2_reg; + } else { + EMIT(PPC_RAW_LI(tmp2_reg, imm)); + src_reg = tmp2_reg; + } + + ret = bpf_jit_emit_probe_mem_store(ctx, src_reg, off, code, image); + if (ret) + return ret; + + ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx, + ctx->idx - 1, 4, -1, code); + if (ret) + return ret; + + break; + + /* + * BPF_STX PROBE_ATOMIC (arena atomic ops) + */ + case BPF_STX | BPF_PROBE_ATOMIC | BPF_W: + case BPF_STX | BPF_PROBE_ATOMIC | BPF_DW: + EMIT(PPC_RAW_ADD(dst_reg, dst_reg, bpf_to_ppc(ARENA_VM_START))); + ret = bpf_jit_emit_atomic_ops(image, ctx, &insn[i], + &jmp_off, &tmp_idx, &addrs[i + 1]); + if (ret) { + if (ret == -EOPNOTSUPP) { + pr_err_ratelimited( + "eBPF filter atomic op code %02x (@%d) unsupported\n", + code, i); + } + return ret; + } + /* LDARX/LWARX should land here on exception. */ + ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx, + tmp_idx, jmp_off, dst_reg, code); + if (ret) + return ret; + + /* Retrieve the dst_reg */ + EMIT(PPC_RAW_SUB(dst_reg, dst_reg, bpf_to_ppc(ARENA_VM_START))); + break; + + /* + * BPF_STX ATOMIC (atomic ops) + */ + case BPF_STX | BPF_ATOMIC | BPF_B: + case BPF_STX | BPF_ATOMIC | BPF_H: + case BPF_STX | BPF_ATOMIC | BPF_W: + case BPF_STX | BPF_ATOMIC | BPF_DW: + if (bpf_atomic_is_load_store(&insn[i])) { + ret = emit_atomic_ld_st(insn[i], ctx, image); + if (ret) + return ret; + + if (size != BPF_DW && insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; + break; + } else if (size == BPF_B || size == BPF_H) { + pr_err_ratelimited( + "eBPF filter atomic op code %02x (@%d) unsupported\n", + code, i); + return -EOPNOTSUPP; + } + + ret = bpf_jit_emit_atomic_ops(image, ctx, &insn[i], + &jmp_off, &tmp_idx, &addrs[i + 1]); + if (ret) { + if (ret == -EOPNOTSUPP) { + pr_err_ratelimited( + "eBPF filter atomic op code %02x (@%d) unsupported\n", + code, i); + } + return ret; + } + break; + + /* + * BPF_LDX + */ + /* dst = *(u8 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEM | BPF_B: + case BPF_LDX | BPF_MEMSX | BPF_B: + case BPF_LDX | BPF_PROBE_MEM | BPF_B: + case BPF_LDX | BPF_PROBE_MEMSX | BPF_B: + /* dst = *(u16 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEM | BPF_H: + case BPF_LDX | BPF_MEMSX | BPF_H: + case BPF_LDX | BPF_PROBE_MEM | BPF_H: + case BPF_LDX | BPF_PROBE_MEMSX | BPF_H: + /* dst = *(u32 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEM | BPF_W: + case BPF_LDX | BPF_MEMSX | BPF_W: + case BPF_LDX | BPF_PROBE_MEM | BPF_W: + case BPF_LDX | BPF_PROBE_MEMSX | BPF_W: + /* dst = *(u64 *)(ul) (src + off) */ + case BPF_LDX | BPF_MEM | BPF_DW: + case BPF_LDX | BPF_PROBE_MEM | BPF_DW: + /* + * As PTR_TO_BTF_ID that uses BPF_PROBE_MEM mode could either be a valid + * kernel pointer or NULL but not a userspace address, execute BPF_PROBE_MEM + * load only if addr is kernel address (see is_kernel_addr()), otherwise + * set dst_reg=0 and move on. + */ + if (BPF_MODE(code) == BPF_PROBE_MEM || BPF_MODE(code) == BPF_PROBE_MEMSX) { + EMIT(PPC_RAW_ADDI(tmp1_reg, src_reg, off)); + if (IS_ENABLED(CONFIG_PPC_BOOK3E_64)) + PPC_LI64(tmp2_reg, 0x8000000000000000ul); + else /* BOOK3S_64 */ + PPC_LI64(tmp2_reg, PAGE_OFFSET); + EMIT(PPC_RAW_CMPLD(tmp1_reg, tmp2_reg)); + PPC_BCC_SHORT(COND_GT, (ctx->idx + 3) * 4); + EMIT(PPC_RAW_LI(dst_reg, 0)); + /* + * Check if 'off' is word aligned for BPF_DW, because + * we might generate two instructions. + */ + if ((BPF_SIZE(code) == BPF_DW && (off & 3)) || + (BPF_SIZE(code) == BPF_B && + BPF_MODE(code) == BPF_PROBE_MEMSX) || + (BPF_SIZE(code) == BPF_B && BPF_MODE(code) == BPF_MEMSX)) + PPC_JMP((ctx->idx + 3) * 4); + else + PPC_JMP((ctx->idx + 2) * 4); + } + + if (BPF_MODE(code) == BPF_MEMSX || BPF_MODE(code) == BPF_PROBE_MEMSX) { + switch (size) { + case BPF_B: + EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); + EMIT(PPC_RAW_EXTSB(dst_reg, dst_reg)); + break; + case BPF_H: + EMIT(PPC_RAW_LHA(dst_reg, src_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_LWA(dst_reg, src_reg, off)); + break; + } + } else { + switch (size) { + case BPF_B: + EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off)); + break; + case BPF_H: + EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off)); + break; + case BPF_DW: + if (off % 4) { + EMIT(PPC_RAW_LI(tmp1_reg, off)); + EMIT(PPC_RAW_LDX(dst_reg, src_reg, tmp1_reg)); + } else { + EMIT(PPC_RAW_LD(dst_reg, src_reg, off)); + } + break; + } + } + + if (size != BPF_DW && insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; + + if (BPF_MODE(code) == BPF_PROBE_MEM) { + ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx, + ctx->idx - 1, 4, dst_reg, code); + if (ret) + return ret; + } + break; + + /* dst = *(u64 *)(ul) (src + ARENA_VM_START + off) */ + case BPF_LDX | BPF_PROBE_MEM32 | BPF_B: + case BPF_LDX | BPF_PROBE_MEM32 | BPF_H: + case BPF_LDX | BPF_PROBE_MEM32 | BPF_W: + case BPF_LDX | BPF_PROBE_MEM32 | BPF_DW: + + EMIT(PPC_RAW_ADD(tmp1_reg, src_reg, bpf_to_ppc(ARENA_VM_START))); + + switch (size) { + case BPF_B: + EMIT(PPC_RAW_LBZ(dst_reg, tmp1_reg, off)); + break; + case BPF_H: + EMIT(PPC_RAW_LHZ(dst_reg, tmp1_reg, off)); + break; + case BPF_W: + EMIT(PPC_RAW_LWZ(dst_reg, tmp1_reg, off)); + break; + case BPF_DW: + if (off % 4) { + EMIT(PPC_RAW_LI(tmp2_reg, off)); + EMIT(PPC_RAW_LDX(dst_reg, tmp1_reg, tmp2_reg)); + } else { + EMIT(PPC_RAW_LD(dst_reg, tmp1_reg, off)); + } + break; + } + + if (size != BPF_DW && insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; + + ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx, + ctx->idx - 1, 4, dst_reg, code); + if (ret) + return ret; + break; + + /* + * Doubleword load + * 16 byte instruction that uses two 'struct bpf_insn' + */ + case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */ + imm64 = ((u64)(u32) insn[i].imm) | + (((u64)(u32) insn[i+1].imm) << 32); + PPC_LI64(dst_reg, imm64); + /* Adjust for two bpf instructions */ + addrs[++i] = ctx->idx * 4; + break; + + /* + * JUMP reg + */ + case BPF_JMP | BPF_JA | BPF_X: + EMIT(PPC_RAW_MTCTR(dst_reg)); + EMIT(PPC_RAW_BCTR()); + break; + + /* + * Return/Exit + */ + case BPF_JMP | BPF_EXIT: + /* + * If this isn't the very last instruction, branch to + * the epilogue. If we _are_ the last instruction, + * we'll just fall through to the epilogue. + */ + if (i != flen - 1) { + ret = bpf_jit_emit_exit_insn(image, ctx, tmp1_reg, exit_addr); + if (ret) + return ret; + } + /* else fall through to the epilogue */ + break; + + /* + * Call kernel helper or bpf function + */ + case BPF_JMP | BPF_CALL: + ctx->seen |= SEEN_FUNC; + + if (src_reg == bpf_to_ppc(BPF_REG_0)) { + if (imm == BPF_FUNC_get_smp_processor_id) { + EMIT(PPC_RAW_LHZ(src_reg, _R13, offsetof(struct paca_struct, paca_index))); + break; + } else if (imm == BPF_FUNC_get_current_task || + imm == BPF_FUNC_get_current_task_btf) { + EMIT(PPC_RAW_LD(src_reg, _R13, offsetof(struct paca_struct, __current))); + break; + } + } + + ret = bpf_jit_get_func_addr(fp, &insn[i], extra_pass, + &func_addr, &func_addr_fixed); + if (ret < 0) + return ret; + + /* + * Call to arch_bpf_timed_may_goto() is emitted by the + * verifier and called with custom calling convention with + * first argument and return value in BPF_REG_AX (_R12). + * + * The generic helper or bpf function call emission path + * may use the same scratch register as BPF_REG_AX to + * materialize the target address. This would clobber AX + * and break timed may_goto semantics. + * + * Emit a minimal indirect call sequence here using a temp + * register and skip the normal post-call return-value move. + */ + + if (func_addr == (u64)arch_bpf_timed_may_goto) { + ret = 0; + if (!IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) + ret = bpf_jit_emit_func_call(image, ctx, func_addr, + tmp1_reg); + + if (ret || IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) { + PPC_LI_ADDR(tmp1_reg, func_addr); + EMIT(PPC_RAW_MTCTR(tmp1_reg)); + EMIT(PPC_RAW_BCTRL()); + } + + break; + } + + /* Take care of powerpc ABI requirements before kfunc call */ + if (insn[i].src_reg == BPF_PSEUDO_KFUNC_CALL) { + if (prepare_for_kfunc_call(fp, image, ctx, &insn[i])) + return -1; + } + + ret = bpf_jit_emit_func_call_rel(image, fimage, ctx, func_addr); + if (ret) + return ret; + + /* move return value from r3 to BPF_REG_0 */ + EMIT(PPC_RAW_MR(bpf_to_ppc(BPF_REG_0), _R3)); + break; + + /* + * Jumps and branches + */ + case BPF_JMP | BPF_JA: + PPC_JMP(addrs[i + 1 + off]); + break; + case BPF_JMP32 | BPF_JA: + PPC_JMP(addrs[i + 1 + imm]); + break; + + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JSGT | BPF_K: + case BPF_JMP | BPF_JSGT | BPF_X: + case BPF_JMP32 | BPF_JGT | BPF_K: + case BPF_JMP32 | BPF_JGT | BPF_X: + case BPF_JMP32 | BPF_JSGT | BPF_K: + case BPF_JMP32 | BPF_JSGT | BPF_X: + true_cond = COND_GT; + goto cond_branch; + case BPF_JMP | BPF_JLT | BPF_K: + case BPF_JMP | BPF_JLT | BPF_X: + case BPF_JMP | BPF_JSLT | BPF_K: + case BPF_JMP | BPF_JSLT | BPF_X: + case BPF_JMP32 | BPF_JLT | BPF_K: + case BPF_JMP32 | BPF_JLT | BPF_X: + case BPF_JMP32 | BPF_JSLT | BPF_K: + case BPF_JMP32 | BPF_JSLT | BPF_X: + true_cond = COND_LT; + goto cond_branch; + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JSGE | BPF_K: + case BPF_JMP | BPF_JSGE | BPF_X: + case BPF_JMP32 | BPF_JGE | BPF_K: + case BPF_JMP32 | BPF_JGE | BPF_X: + case BPF_JMP32 | BPF_JSGE | BPF_K: + case BPF_JMP32 | BPF_JSGE | BPF_X: + true_cond = COND_GE; + goto cond_branch; + case BPF_JMP | BPF_JLE | BPF_K: + case BPF_JMP | BPF_JLE | BPF_X: + case BPF_JMP | BPF_JSLE | BPF_K: + case BPF_JMP | BPF_JSLE | BPF_X: + case BPF_JMP32 | BPF_JLE | BPF_K: + case BPF_JMP32 | BPF_JLE | BPF_X: + case BPF_JMP32 | BPF_JSLE | BPF_K: + case BPF_JMP32 | BPF_JSLE | BPF_X: + true_cond = COND_LE; + goto cond_branch; + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP32 | BPF_JEQ | BPF_K: + case BPF_JMP32 | BPF_JEQ | BPF_X: + true_cond = COND_EQ; + goto cond_branch; + case BPF_JMP | BPF_JNE | BPF_K: + case BPF_JMP | BPF_JNE | BPF_X: + case BPF_JMP32 | BPF_JNE | BPF_K: + case BPF_JMP32 | BPF_JNE | BPF_X: + true_cond = COND_NE; + goto cond_branch; + case BPF_JMP | BPF_JSET | BPF_K: + case BPF_JMP | BPF_JSET | BPF_X: + case BPF_JMP32 | BPF_JSET | BPF_K: + case BPF_JMP32 | BPF_JSET | BPF_X: + true_cond = COND_NE; + /* Fall through */ + +cond_branch: + switch (code) { + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JLT | BPF_X: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JLE | BPF_X: + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP | BPF_JNE | BPF_X: + case BPF_JMP32 | BPF_JGT | BPF_X: + case BPF_JMP32 | BPF_JLT | BPF_X: + case BPF_JMP32 | BPF_JGE | BPF_X: + case BPF_JMP32 | BPF_JLE | BPF_X: + case BPF_JMP32 | BPF_JEQ | BPF_X: + case BPF_JMP32 | BPF_JNE | BPF_X: + /* unsigned comparison */ + if (BPF_CLASS(code) == BPF_JMP32) + EMIT(PPC_RAW_CMPLW(dst_reg, src_reg)); + else + EMIT(PPC_RAW_CMPLD(dst_reg, src_reg)); + break; + case BPF_JMP | BPF_JSGT | BPF_X: + case BPF_JMP | BPF_JSLT | BPF_X: + case BPF_JMP | BPF_JSGE | BPF_X: + case BPF_JMP | BPF_JSLE | BPF_X: + case BPF_JMP32 | BPF_JSGT | BPF_X: + case BPF_JMP32 | BPF_JSLT | BPF_X: + case BPF_JMP32 | BPF_JSGE | BPF_X: + case BPF_JMP32 | BPF_JSLE | BPF_X: + /* signed comparison */ + if (BPF_CLASS(code) == BPF_JMP32) + EMIT(PPC_RAW_CMPW(dst_reg, src_reg)); + else + EMIT(PPC_RAW_CMPD(dst_reg, src_reg)); + break; + case BPF_JMP | BPF_JSET | BPF_X: + case BPF_JMP32 | BPF_JSET | BPF_X: + if (BPF_CLASS(code) == BPF_JMP) { + EMIT(PPC_RAW_AND_DOT(tmp1_reg, dst_reg, src_reg)); + } else { + EMIT(PPC_RAW_AND(tmp1_reg, dst_reg, src_reg)); + EMIT(PPC_RAW_RLWINM_DOT(tmp1_reg, tmp1_reg, 0, 0, 31)); + } + break; + case BPF_JMP | BPF_JNE | BPF_K: + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JLT | BPF_K: + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JLE | BPF_K: + case BPF_JMP32 | BPF_JNE | BPF_K: + case BPF_JMP32 | BPF_JEQ | BPF_K: + case BPF_JMP32 | BPF_JGT | BPF_K: + case BPF_JMP32 | BPF_JLT | BPF_K: + case BPF_JMP32 | BPF_JGE | BPF_K: + case BPF_JMP32 | BPF_JLE | BPF_K: + { + bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32; + + /* + * Need sign-extended load, so only positive + * values can be used as imm in cmpldi + */ + if (imm >= 0 && imm < 32768) { + if (is_jmp32) + EMIT(PPC_RAW_CMPLWI(dst_reg, imm)); + else + EMIT(PPC_RAW_CMPLDI(dst_reg, imm)); + } else { + /* sign-extending load */ + PPC_LI32(tmp1_reg, imm); + /* ... but unsigned comparison */ + if (is_jmp32) + EMIT(PPC_RAW_CMPLW(dst_reg, tmp1_reg)); + else + EMIT(PPC_RAW_CMPLD(dst_reg, tmp1_reg)); + } + break; + } + case BPF_JMP | BPF_JSGT | BPF_K: + case BPF_JMP | BPF_JSLT | BPF_K: + case BPF_JMP | BPF_JSGE | BPF_K: + case BPF_JMP | BPF_JSLE | BPF_K: + case BPF_JMP32 | BPF_JSGT | BPF_K: + case BPF_JMP32 | BPF_JSLT | BPF_K: + case BPF_JMP32 | BPF_JSGE | BPF_K: + case BPF_JMP32 | BPF_JSLE | BPF_K: + { + bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32; + + /* + * signed comparison, so any 16-bit value + * can be used in cmpdi + */ + if (imm >= -32768 && imm < 32768) { + if (is_jmp32) + EMIT(PPC_RAW_CMPWI(dst_reg, imm)); + else + EMIT(PPC_RAW_CMPDI(dst_reg, imm)); + } else { + PPC_LI32(tmp1_reg, imm); + if (is_jmp32) + EMIT(PPC_RAW_CMPW(dst_reg, tmp1_reg)); + else + EMIT(PPC_RAW_CMPD(dst_reg, tmp1_reg)); + } + break; + } + case BPF_JMP | BPF_JSET | BPF_K: + case BPF_JMP32 | BPF_JSET | BPF_K: + /* andi does not sign-extend the immediate */ + if (imm >= 0 && imm < 32768) + /* PPC_ANDI is _only/always_ dot-form */ + EMIT(PPC_RAW_ANDI(tmp1_reg, dst_reg, imm)); + else { + PPC_LI32(tmp1_reg, imm); + if (BPF_CLASS(code) == BPF_JMP) { + EMIT(PPC_RAW_AND_DOT(tmp1_reg, dst_reg, + tmp1_reg)); + } else { + EMIT(PPC_RAW_AND(tmp1_reg, dst_reg, tmp1_reg)); + EMIT(PPC_RAW_RLWINM_DOT(tmp1_reg, tmp1_reg, + 0, 0, 31)); + } + } + break; + } + PPC_BCC(true_cond, addrs[i + 1 + off]); + break; + + /* + * Tail call + */ + case BPF_JMP | BPF_TAIL_CALL: + ctx->seen |= SEEN_TAILCALL; + ret = bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]); + if (ret < 0) + return ret; + break; + + default: + /* + * The filter contains something cruel & unusual. + * We don't handle it, but also there shouldn't be + * anything missing from our list. + */ + pr_err_ratelimited("eBPF filter opcode %04x (@%d) unsupported\n", + code, i); + return -ENOTSUPP; + } + } + + /* Set end-of-body-code address for exit. */ + addrs[i] = ctx->idx * 4; + + return 0; +} diff --git a/arch/powerpc/net/bpf_timed_may_goto.S b/arch/powerpc/net/bpf_timed_may_goto.S new file mode 100644 index 000000000..84ecf6fa7 --- /dev/null +++ b/arch/powerpc/net/bpf_timed_may_goto.S @@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2025 IBM Corporation, Saket Kumar Bhaskar <skb99@linux.ibm.com> */ + +#include <linux/linkage.h> +#include <asm/ppc_asm.h> + +/* + * arch_bpf_timed_may_goto() trampoline for powerpc64 + * + * Custom BPF convention (verifier/JIT): + * - input: stack offset in BPF_REG_AX (r12) + * - output: updated count in BPF_REG_AX (r12) + * + * Call bpf_check_timed_may_goto(ptr) with normal powerpc64 ABI: + * - r3 = ptr, return in r3 + * + * Preserve BPF regs R0-R5 (mapping: r8, r3-r7). + */ + +SYM_FUNC_START(arch_bpf_timed_may_goto) + /* Prologue: save LR, allocate frame */ + mflr r0 + std r0, 16(r1) + stdu r1, -112(r1) + + /* Save BPF registers R0 - R5 (r8, r3-r7) */ + std r3, 32(r1) + std r4, 40(r1) + std r5, 48(r1) + std r6, 56(r1) + std r7, 64(r1) + std r8, 72(r1) + + /* + * r3 = BPF_REG_FP + BPF_REG_AX + * BPF_REG_FP is r31; BPF_REG_AX is r12 (stack offset in bytes). + */ + add r3, r31, r12 + bl CFUNC(bpf_check_timed_may_goto) + + /* Put return value back into AX */ + mr r12, r3 + + /* Restore BPF registers R0 - R5 (r8, r3-r7) */ + ld r3, 32(r1) + ld r4, 40(r1) + ld r5, 48(r1) + ld r6, 56(r1) + ld r7, 64(r1) + ld r8, 72(r1) + + /* Epilogue: pop frame, restore LR, return */ + addi r1, r1, 112 + ld r0, 16(r1) + mtlr r0 + blr +SYM_FUNC_END(arch_bpf_timed_may_goto) |
