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| author | Kees Cook <kees+treewide@kernel.org> | 2026-09-02 15:31:14 -0700 |
|---|---|---|
| committer | Kees Cook <kees@kernel.org> | 2026-09-04 21:37:00 -0700 |
| commit | 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch) | |
| tree | c65086f9bdcd48c6360fb7cb4598bca084da1f32 /io_uring/bpf-ops.c | |
| download | linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip | |
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci
This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.
Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.
Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'io_uring/bpf-ops.c')
| -rw-r--r-- | io_uring/bpf-ops.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/io_uring/bpf-ops.c b/io_uring/bpf-ops.c new file mode 100644 index 000000000..cf2bd068e --- /dev/null +++ b/io_uring/bpf-ops.c @@ -0,0 +1,275 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/mutex.h> +#include <linux/bpf.h> +#include <linux/bpf_verifier.h> + +#include "io_uring.h" +#include "register.h" +#include "loop.h" +#include "memmap.h" +#include "bpf-ops.h" + +static DEFINE_MUTEX(io_bpf_ctrl_mutex); +static const struct btf_type *loop_params_type; + +__bpf_kfunc_start_defs(); + +__bpf_kfunc int bpf_io_uring_submit_sqes(struct iou_ctx *loop_ctx, u32 nr) +{ + struct io_ring_ctx *ctx = io_loop_demangle_ctx(loop_ctx); + + return io_submit_sqes(ctx, nr); +} + +__bpf_kfunc +__u8 *bpf_io_uring_get_region(struct iou_ctx *loop_ctx, __u32 region_id, + const size_t rdwr_buf_size) +{ + struct io_ring_ctx *ctx = io_loop_demangle_ctx(loop_ctx); + struct io_mapped_region *r; + + lockdep_assert_held(&ctx->uring_lock); + + switch (region_id) { + case IOU_REGION_MEM: + r = &ctx->param_region; + break; + case IOU_REGION_CQ: + r = &ctx->ring_region; + break; + case IOU_REGION_SQ: + r = &ctx->sq_region; + break; + default: + return NULL; + } + + if (unlikely(rdwr_buf_size > io_region_size(r))) + return NULL; + return io_region_get_ptr(r); +} + +__bpf_kfunc_end_defs(); + +BTF_KFUNCS_START(io_uring_kfunc_set) +BTF_ID_FLAGS(func, bpf_io_uring_submit_sqes, KF_SLEEPABLE); +BTF_ID_FLAGS(func, bpf_io_uring_get_region, KF_RET_NULL); +BTF_KFUNCS_END(io_uring_kfunc_set) + +static const struct btf_kfunc_id_set bpf_io_uring_kfunc_set = { + .owner = THIS_MODULE, + .set = &io_uring_kfunc_set, +}; + +static int io_bpf_ops__loop_step(struct iou_ctx *ctx, + struct iou_loop_params *lp) +{ + return IOU_LOOP_STOP; +} + +static struct io_uring_bpf_ops io_bpf_ops_stubs = { + .loop_step = io_bpf_ops__loop_step, +}; + +static bool bpf_io_is_valid_access(int off, int size, + enum bpf_access_type type, + const struct bpf_prog *prog, + struct bpf_insn_access_aux *info) +{ + if (type != BPF_READ) + return false; + if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS) + return false; + if (off % size != 0) + return false; + + return btf_ctx_access(off, size, type, prog, info); +} + +static int bpf_io_btf_struct_access(struct bpf_verifier_log *log, + const struct bpf_reg_state *reg, int off, + int size) +{ + const struct btf_type *t = btf_type_by_id(reg->btf, reg->btf_id); + + if (t == loop_params_type) { + if (off + size <= offsetofend(struct iou_loop_params, cq_wait_idx)) + return SCALAR_VALUE; + } + + return -EACCES; +} + +static const struct bpf_verifier_ops bpf_io_verifier_ops = { + .get_func_proto = bpf_base_func_proto, + .is_valid_access = bpf_io_is_valid_access, + .btf_struct_access = bpf_io_btf_struct_access, +}; + +static const struct btf_type * +io_lookup_struct_type(struct btf *btf, const char *name) +{ + s32 type_id; + + type_id = btf_find_by_name_kind(btf, name, BTF_KIND_STRUCT); + if (type_id < 0) + return NULL; + return btf_type_by_id(btf, type_id); +} + +static int bpf_io_init(struct btf *btf) +{ + int ret; + + loop_params_type = io_lookup_struct_type(btf, "iou_loop_params"); + if (!loop_params_type) { + pr_err("io_uring: Failed to locate iou_loop_params\n"); + return -EINVAL; + } + + ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, + &bpf_io_uring_kfunc_set); + if (ret) { + pr_err("io_uring: Failed to register kfuncs (%d)\n", ret); + return ret; + } + return 0; +} + +static int bpf_io_check_member(const struct btf_type *t, + const struct btf_member *member, + const struct bpf_prog *prog) +{ + return 0; +} + +static int bpf_io_init_member(const struct btf_type *t, + const struct btf_member *member, + void *kdata, const void *udata) +{ + u32 moff = __btf_member_bit_offset(t, member) / 8; + const struct io_uring_bpf_ops *uops = udata; + struct io_uring_bpf_ops *ops = kdata; + + switch (moff) { + case offsetof(struct io_uring_bpf_ops, ring_fd): + ops->ring_fd = uops->ring_fd; + return 1; + } + return 0; +} + +static int io_install_bpf(struct io_ring_ctx *ctx, struct io_uring_bpf_ops *ops) +{ + if (ctx->flags & (IORING_SETUP_SQPOLL | IORING_SETUP_IOPOLL)) + return -EOPNOTSUPP; + if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) + return -EOPNOTSUPP; + + if (ctx->bpf_ops) + return -EBUSY; + if (ops->priv) + return -EBUSY; + if (WARN_ON_ONCE(!ops->loop_step)) + return -EINVAL; + + ops->priv = ctx; + ctx->bpf_ops = ops; + ctx->loop_step = ops->loop_step; + return 0; +} + +static int bpf_io_reg(void *kdata, struct bpf_link *link) +{ + struct io_uring_bpf_ops *ops = kdata; + struct io_ring_ctx *ctx; + struct file *file; + int ret = -EBUSY; + + file = io_uring_ctx_get_file(ops->ring_fd, false); + if (IS_ERR(file)) + return PTR_ERR(file); + ctx = file->private_data; + + scoped_guard(mutex, &io_bpf_ctrl_mutex) { + guard(mutex)(&ctx->uring_lock); + ret = io_install_bpf(ctx, ops); + } + + fput(file); + return ret; +} + +static void io_eject_bpf(struct io_ring_ctx *ctx) +{ + struct io_uring_bpf_ops *ops = ctx->bpf_ops; + + if (WARN_ON_ONCE(!ops)) + return; + if (WARN_ON_ONCE(ops->priv != ctx)) + return; + + ops->priv = NULL; + ctx->bpf_ops = NULL; + ctx->loop_step = NULL; +} + +static void bpf_io_unreg(void *kdata, struct bpf_link *link) +{ + struct io_uring_bpf_ops *ops = kdata; + struct io_ring_ctx *ctx; + + guard(mutex)(&io_bpf_ctrl_mutex); + ctx = ops->priv; + if (ctx) { + guard(mutex)(&ctx->uring_lock); + if (WARN_ON_ONCE(ctx->bpf_ops != ops)) + return; + + io_eject_bpf(ctx); + } +} + +void io_unregister_bpf_ops(struct io_ring_ctx *ctx) +{ + /* + * ->bpf_ops is write protected by io_bpf_ctrl_mutex and uring_lock, + * and read protected by either. Try to avoid taking the global lock + * for rings that never had any bpf installed. + */ + scoped_guard(mutex, &ctx->uring_lock) { + if (!ctx->bpf_ops) + return; + } + + guard(mutex)(&io_bpf_ctrl_mutex); + guard(mutex)(&ctx->uring_lock); + if (ctx->bpf_ops) + io_eject_bpf(ctx); +} + +static struct bpf_struct_ops bpf_ring_ops = { + .verifier_ops = &bpf_io_verifier_ops, + .reg = bpf_io_reg, + .unreg = bpf_io_unreg, + .check_member = bpf_io_check_member, + .init_member = bpf_io_init_member, + .init = bpf_io_init, + .cfi_stubs = &io_bpf_ops_stubs, + .name = "io_uring_bpf_ops", + .owner = THIS_MODULE, +}; + +static int __init io_uring_bpf_init(void) +{ + int ret; + + ret = register_bpf_struct_ops(&bpf_ring_ops, io_uring_bpf_ops); + if (ret) { + pr_err("io_uring: Failed to register struct_ops (%d)\n", ret); + return ret; + } + + return 0; +} +__initcall(io_uring_bpf_init); |
