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| author | Sang-Heon Jeon <ekffu200098@gmail.com> | 2026-08-24 01:18:14 +0900 |
|---|---|---|
| committer | Julia Lawall <Julia.Lawall@inria.fr> | 2026-08-23 22:12:11 +0200 |
| commit | 2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c (patch) | |
| tree | dcc4da1d99f17541c5590ac63c77da4bf372a4ab /arch/x86/entry/vdso | |
| download | linux-stable-2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c.tar.gz linux-stable-2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c.zip | |
coccinelle: alloc_cast: drop removed allocatorsgrafted
- pci_alloc_consistent() and pci_zalloc_consistent() were removed by
commit 7968778914e5
("PCI: Remove the deprecated "pci-dma-compat.h" API")
- kmem_alloc() was removed by commit f078d4ea8276
("xfs: convert kmem_alloc() to kmalloc()")
- kmem_zalloc() was removed by commit 10634530f7ba
("xfs: convert kmem_zalloc() to kzalloc()")
- kmem_zone_alloc() and kmem_zone_zalloc() were removed by commit
bae633a4a283 ("xfs: remove xfs_zone_{alloc,zalloc} helpers")
So drop them from the rules.
No functional change.
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Diffstat (limited to 'arch/x86/entry/vdso')
32 files changed, 1636 insertions, 0 deletions
diff --git a/arch/x86/entry/vdso/.gitignore b/arch/x86/entry/vdso/.gitignore new file mode 100644 index 000000000..b57a52a85 --- /dev/null +++ b/arch/x86/entry/vdso/.gitignore @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0-only +*.lds +*.so +*.so.dbg +vdso*-image*.c +vdso2c diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile new file mode 100644 index 000000000..987b43fd4 --- /dev/null +++ b/arch/x86/entry/vdso/Makefile @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Building vDSO images for x86. +# + +# Regular kernel objects +obj-y := vma.o extable.o +obj-$(CONFIG_COMPAT_32) += vdso32-setup.o + +# vDSO directories +obj-$(CONFIG_X86_64) += vdso64/ +obj-$(CONFIG_COMPAT_32) += vdso32/ diff --git a/arch/x86/entry/vdso/common/Makefile.include b/arch/x86/entry/vdso/common/Makefile.include new file mode 100644 index 000000000..687b3d89b --- /dev/null +++ b/arch/x86/entry/vdso/common/Makefile.include @@ -0,0 +1,89 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Building vDSO images for x86. +# + +# Include the generic Makefile to check the built vDSO: +include $(srctree)/lib/vdso/Makefile.include + +obj-y += $(foreach x,$(vdsos-y),vdso$(x)-image.o) + +targets += $(foreach x,$(vdsos-y),vdso$(x)-image.c vdso$(x).so vdso$(x).so.dbg vdso$(x).lds) +targets += $(vobjs-y) + +# vobjs-y with $(obj)/ prepended +vobjs := $(addprefix $(obj)/,$(vobjs-y)) + +# Options for vdso*.lds +CPPFLAGS_VDSO_LDS := -P -C -I$(src)/.. +$(obj)/%.lds : KBUILD_CPPFLAGS += $(CPPFLAGS_VDSO_LDS) + +# +# Options from KBUILD_[AC]FLAGS that should *NOT* be kept +# +flags-remove-y += \ + -D__KERNEL__ -mcmodel=kernel -mregparm=3 \ + -fno-pic -fno-PIC -fno-pie -fno-PIE \ + -mfentry -pg \ + $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(KSTACK_ERASE_CFLAGS) \ + $(RETPOLINE_CFLAGS) $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) \ + $(PADDING_CFLAGS) + +# +# Don't omit frame pointers for ease of userspace debugging, but do +# optimize sibling calls. +# +flags-y += -D__DISABLE_EXPORTS +flags-y += -DDISABLE_BRANCH_PROFILING +flags-y += -DBUILD_VDSO +flags-y += -I$(src)/.. -I$(srctree) +flags-y += -O2 -fpic +flags-y += -fno-stack-protector +flags-y += -fno-omit-frame-pointer +flags-y += -foptimize-sibling-calls +flags-y += -fasynchronous-unwind-tables + +# Reset cf protections enabled by compiler default +flags-y += $(call cc-option, -fcf-protection=none) +flags-$(X86_USER_SHADOW_STACK) += $(call cc-option, -fcf-protection=return) +# When user space IBT is supported, enable this. +# flags-$(CONFIG_USER_IBT) += $(call cc-option, -fcf-protection=branch) + +flags-$(CONFIG_MITIGATION_RETPOLINE) += $(RETPOLINE_VDSO_CFLAGS) + +# These need to be conditional on $(vobjs) as they do not apply to +# the output vdso*-image.o files which are standard kernel objects. +$(vobjs) : KBUILD_AFLAGS := \ + $(filter-out $(flags-remove-y),$(KBUILD_AFLAGS)) $(flags-y) +$(vobjs) : KBUILD_CFLAGS := \ + $(filter-out $(flags-remove-y),$(KBUILD_CFLAGS)) $(flags-y) + +# +# The VDSO images are built using a special linker script. +# +VDSO_LDFLAGS := -shared --hash-style=both --build-id=sha1 --no-undefined \ + $(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack + +quiet_cmd_vdso = VDSO $@ + cmd_vdso = $(LD) -o $@ \ + $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$*) \ + -T $(filter %.lds,$^) $(filter %.o,$^) +quiet_cmd_vdso_and_check = VDSO $@ + cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check) + +$(obj)/vdso%.so.dbg: $(obj)/vdso%.lds FORCE + $(call if_changed,vdso_and_check) + +$(obj)/%.so: OBJCOPYFLAGS := -S --remove-section __ex_table +$(obj)/%.so: $(obj)/%.so.dbg FORCE + $(call if_changed,objcopy) + +VDSO2C = $(objtree)/arch/x86/tools/vdso2c + +quiet_cmd_vdso2c = VDSO2C $@ + cmd_vdso2c = $(VDSO2C) $< $(<:%.dbg=%) $@ + +$(obj)/%-image.c: $(obj)/%.so.dbg $(obj)/%.so $(VDSO2C) FORCE + $(call if_changed,vdso2c) + +$(obj)/%-image.o: $(obj)/%-image.c diff --git a/arch/x86/entry/vdso/common/note.S b/arch/x86/entry/vdso/common/note.S new file mode 100644 index 000000000..2cbd39939 --- /dev/null +++ b/arch/x86/entry/vdso/common/note.S @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text. + * Here we can supply some information useful to userland. + */ + +#include <linux/build-salt.h> +#include <linux/version.h> +#include <linux/elfnote.h> + +/* Ideally this would use UTS_NAME, but using a quoted string here + doesn't work. Remember to change this when changing the + kernel's name. */ +ELFNOTE_START(Linux, 0, "a") + .long LINUX_VERSION_CODE +ELFNOTE_END + +BUILD_SALT diff --git a/arch/x86/entry/vdso/common/vclock_gettime.c b/arch/x86/entry/vdso/common/vclock_gettime.c new file mode 100644 index 000000000..304dbd1f9 --- /dev/null +++ b/arch/x86/entry/vdso/common/vclock_gettime.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Fast user context implementation of clock_gettime, gettimeofday, and time. + * + * Copyright 2006 Andi Kleen, SUSE Labs. + * Copyright 2019 ARM Limited + * + * 32 Bit compat layer by Stefani Seibold <stefani@seibold.net> + * sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany + */ +#include <linux/time.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <vdso/gettime.h> + +#include "lib/vdso/gettimeofday.c" + +#if defined(__x86_64__) || defined(CONFIG_COMPAT_32BIT_TIME) +int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz) +{ + return __cvdso_gettimeofday(tv, tz); +} + +int gettimeofday(struct __kernel_old_timeval *, struct timezone *) + __attribute__((weak, alias("__vdso_gettimeofday"))); + +__kernel_old_time_t __vdso_time(__kernel_old_time_t *t) +{ + return __cvdso_time(t); +} + +__kernel_old_time_t time(__kernel_old_time_t *t) __attribute__((weak, alias("__vdso_time"))); +#endif /* CONFIG_COMPAT_32BIT_TIME */ + + +#if defined(CONFIG_X86_64) && !defined(BUILD_VDSO32_64) +/* both 64-bit and x32 use these */ +int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) +{ + return __cvdso_clock_gettime(clock, ts); +} + +int clock_gettime(clockid_t, struct __kernel_timespec *) + __attribute__((weak, alias("__vdso_clock_gettime"))); + +int __vdso_clock_getres(clockid_t clock, + struct __kernel_timespec *res) +{ + return __cvdso_clock_getres(clock, res); +} +int clock_getres(clockid_t, struct __kernel_timespec *) + __attribute__((weak, alias("__vdso_clock_getres"))); + +#else +/* i386 only */ +#ifdef CONFIG_COMPAT_32BIT_TIME +int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts) +{ + return __cvdso_clock_gettime32(clock, ts); +} + +int clock_gettime(clockid_t, struct old_timespec32 *) + __attribute__((weak, alias("__vdso_clock_gettime"))); + +int __vdso_clock_getres(clockid_t clock, struct old_timespec32 *res) +{ + return __cvdso_clock_getres_time32(clock, res); +} + +int clock_getres(clockid_t, struct old_timespec32 *) + __attribute__((weak, alias("__vdso_clock_getres"))); +#endif /* CONFIG_COMPAT_32BIT_TIME */ + +int __vdso_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts) +{ + return __cvdso_clock_gettime(clock, ts); +} + +int clock_gettime64(clockid_t, struct __kernel_timespec *) + __attribute__((weak, alias("__vdso_clock_gettime64"))); + +int __vdso_clock_getres_time64(clockid_t clock, struct __kernel_timespec *ts) +{ + return __cvdso_clock_getres(clock, ts); +} + +int clock_getres_time64(clockid_t, struct __kernel_timespec *) + __attribute__((weak, alias("__vdso_clock_getres_time64"))); +#endif diff --git a/arch/x86/entry/vdso/common/vdso-layout.lds.S b/arch/x86/entry/vdso/common/vdso-layout.lds.S new file mode 100644 index 000000000..a1e30be3e --- /dev/null +++ b/arch/x86/entry/vdso/common/vdso-layout.lds.S @@ -0,0 +1,109 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <asm/vdso.h> +#include <asm/vdso/vsyscall.h> +#include <vdso/datapage.h> + +/* + * Linker script for vDSO. This is an ELF shared object prelinked to + * its virtual address, and with only one read-only segment. + * This script controls its layout. + */ + +SECTIONS +{ + /* + * User/kernel shared data is before the vDSO. This may be a little + * uglier than putting it after the vDSO, but it avoids issues with + * non-allocatable things that dangle past the end of the PT_LOAD + * segment. + */ + + VDSO_VVAR_SYMS + + vclock_pages = VDSO_VCLOCK_PAGES_START(vdso_u_data); + pvclock_page = vclock_pages + VDSO_PAGE_PVCLOCK_OFFSET * PAGE_SIZE; + hvclock_page = vclock_pages + VDSO_PAGE_HVCLOCK_OFFSET * PAGE_SIZE; + + . = SIZEOF_HEADERS; + + .hash : { *(.hash) } :text + .gnu.hash : { *(.gnu.hash) } + .dynsym : { *(.dynsym) } + .dynstr : { *(.dynstr) } + .gnu.version : { *(.gnu.version) } + .gnu.version_d : { *(.gnu.version_d) } + .gnu.version_r : { *(.gnu.version_r) } + + .dynamic : { *(.dynamic) } :text :dynamic + + .rodata : { + *(.rodata*) + *(.data*) + *(.sdata*) + *(.got.plt) *(.got) + *(.gnu.linkonce.d.*) + *(.bss*) + *(.dynbss*) + *(.gnu.linkonce.b.*) + } :text + + .note.gnu.property : { + *(.note.gnu.property) + } :text :note :gnu_property + .note : { + *(.note*) + } :text :note + + .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr + .eh_frame : { + KEEP (*(.eh_frame)) + *(.eh_frame.*) + } :text + + /* + * Text is well-separated from actual data: there's plenty of + * stuff that isn't used at runtime in between. + */ + + .text : { + *(.text*) + } :text =0x90909090, + + + + .altinstructions : { *(.altinstructions) } :text + .altinstr_replacement : { *(.altinstr_replacement) } :text + + __ex_table : { *(__ex_table) } :text + + /DISCARD/ : { + *(.discard) + *(.discard.*) + *(__bug_table) + } +} + +/* + * Very old versions of ld do not recognize this name token; use the constant. + */ +#define PT_GNU_EH_FRAME 0x6474e550 +#define PT_GNU_STACK 0x6474e551 +#define PT_GNU_PROPERTY 0x6474e553 + +/* + * We must supply the ELF program headers explicitly to get just one + * PT_LOAD segment, and set the flags explicitly to make segments read-only. +*/ +#define PF_R FLAGS(4) +#define PF_RW FLAGS(6) +#define PF_RX FLAGS(5) + +PHDRS +{ + text PT_LOAD PF_RX FILEHDR PHDRS; + dynamic PT_DYNAMIC PF_R; + note PT_NOTE PF_R; + eh_frame_hdr PT_GNU_EH_FRAME PF_R; + gnu_stack PT_GNU_STACK PF_RW; + gnu_property PT_GNU_PROPERTY PF_R; +} diff --git a/arch/x86/entry/vdso/common/vfutex.c b/arch/x86/entry/vdso/common/vfutex.c new file mode 100644 index 000000000..454f05927 --- /dev/null +++ b/arch/x86/entry/vdso/common/vfutex.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <vdso/futex.h> + +/* + * Assembly template for the try unlock functions. The basic functionality is: + * + * mov esi, %eax Move the TID into EAX + * xor %ecx, %ecx Clear ECX + * lock_cmpxchgl %ecx, (%rdi) Attempt the TID -> 0 transition + * .Lcs_start: Start of the critical section + * jnz .Lcs_end If cmpxchl failed jump to the end + * .Lcs_success: Start of the success section + * movq %rcx, (%rdx) Set the pending op pointer to 0 + * .Lcs_end: End of the critical section + * + * .Lcs_start and .Lcs_end establish the critical section range. .Lcs_success is + * technically not required, but there for illustration, debugging and testing. + * + * When CONFIG_COMPAT is enabled then the 64-bit VDSO provides two functions. + * One for the regular 64-bit sized pending operation pointer and one for a + * 32-bit sized pointer to support gaming emulators. + * + * The 32-bit VDSO provides only the one for 32-bit sized pointers. + */ +#define __stringify_1(x...) #x +#define __stringify(x...) __stringify_1(x) + +#define LABEL(prefix, which) __stringify(prefix##_try_unlock_cs_##which:) + +#define JNZ_END(prefix) "jnz " __stringify(prefix) "_try_unlock_cs_end\n" + +#define CLEAR_POPQ "movq %[zero], %a[pop]\n" +#define CLEAR_POPL "movl %k[zero], %a[pop]\n" + +#define futex_robust_try_unlock(prefix, clear_pop, __lock, __tid, __pop)\ +({ \ + asm volatile ( \ + " \n" \ + " lock cmpxchgl %k[zero], %a[lock] \n" \ + " \n" \ + LABEL(prefix, start) \ + " \n" \ + JNZ_END(prefix) \ + " \n" \ + LABEL(prefix, success) \ + " \n" \ + clear_pop \ + " \n" \ + LABEL(prefix, end) \ + : [tid] "+&a" (__tid) \ + : [lock] "D" (__lock), \ + [pop] "d" (__pop), \ + [zero] "r" (0UL) \ + : "memory" \ + ); \ + __tid; \ +}) + +#ifdef __x86_64__ +__u32 __vdso_futex_robust_list64_try_unlock(__u32 *lock, __u32 tid, __u64 *pop) +{ + return futex_robust_try_unlock(__futex_list64, CLEAR_POPQ, lock, tid, pop); +} +#endif /* __x86_64__ */ + +#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT) +__u32 __vdso_futex_robust_list32_try_unlock(__u32 *lock, __u32 tid, __u32 *pop) +{ + return futex_robust_try_unlock(__futex_list32, CLEAR_POPL, lock, tid, pop); +} +#endif /* CONFIG_X86_32 || CONFIG_COMPAT */ diff --git a/arch/x86/entry/vdso/common/vgetcpu.c b/arch/x86/entry/vdso/common/vgetcpu.c new file mode 100644 index 000000000..6381b472b --- /dev/null +++ b/arch/x86/entry/vdso/common/vgetcpu.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2006 Andi Kleen, SUSE Labs. + * + * Fast user context implementation of getcpu() + */ + +#include <linux/kernel.h> +#include <asm/segment.h> +#include <vdso/processor.h> + +notrace long +__vdso_getcpu(unsigned *cpu, unsigned *node, void *unused) +{ + vdso_read_cpunode(cpu, node); + + return 0; +} + +long getcpu(unsigned *cpu, unsigned *node, void *tcache) + __attribute__((weak, alias("__vdso_getcpu"))); diff --git a/arch/x86/entry/vdso/extable.c b/arch/x86/entry/vdso/extable.c new file mode 100644 index 000000000..afcf5b65b --- /dev/null +++ b/arch/x86/entry/vdso/extable.c @@ -0,0 +1,46 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/err.h> +#include <linux/mm.h> +#include <asm/current.h> +#include <asm/traps.h> +#include <asm/vdso.h> + +struct vdso_exception_table_entry { + int insn, fixup; +}; + +bool fixup_vdso_exception(struct pt_regs *regs, int trapnr, + unsigned long error_code, unsigned long fault_addr) +{ + const struct vdso_image *image = current->mm->context.vdso_image; + const struct vdso_exception_table_entry *extable; + unsigned int nr_entries, i; + unsigned long base; + + /* + * Do not attempt to fixup #DB or #BP. It's impossible to identify + * whether or not a #DB/#BP originated from within an SGX enclave and + * SGX enclaves are currently the only use case for vDSO fixup. + */ + if (trapnr == X86_TRAP_DB || trapnr == X86_TRAP_BP) + return false; + + if (!current->mm->context.vdso) + return false; + + base = (unsigned long)current->mm->context.vdso + image->extable_base; + nr_entries = image->extable_len / (sizeof(*extable)); + extable = image->extable; + + for (i = 0; i < nr_entries; i++) { + if (regs->ip == base + extable[i].insn) { + regs->ip = base + extable[i].fixup; + regs->di = trapnr; + regs->si = error_code; + regs->dx = fault_addr; + return true; + } + } + + return false; +} diff --git a/arch/x86/entry/vdso/extable.h b/arch/x86/entry/vdso/extable.h new file mode 100644 index 000000000..baba612b8 --- /dev/null +++ b/arch/x86/entry/vdso/extable.h @@ -0,0 +1,28 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_EXTABLE_H +#define __VDSO_EXTABLE_H + +/* + * Inject exception fixup for vDSO code. Unlike normal exception fixup, + * vDSO uses a dedicated handler the addresses are relative to the overall + * exception table, not each individual entry. + */ +#ifdef __ASSEMBLER__ +#define _ASM_VDSO_EXTABLE_HANDLE(from, to) \ + ASM_VDSO_EXTABLE_HANDLE from to + +.macro ASM_VDSO_EXTABLE_HANDLE from:req to:req + .pushsection __ex_table, "a" + .long (\from) - __ex_table + .long (\to) - __ex_table + .popsection +.endm +#else +#define _ASM_VDSO_EXTABLE_HANDLE(from, to) \ + ".pushsection __ex_table, \"a\"\n" \ + ".long (" #from ") - __ex_table\n" \ + ".long (" #to ") - __ex_table\n" \ + ".popsection\n" +#endif + +#endif /* __VDSO_EXTABLE_H */ diff --git a/arch/x86/entry/vdso/vdso32-setup.c b/arch/x86/entry/vdso/vdso32-setup.c new file mode 100644 index 000000000..8894013ee --- /dev/null +++ b/arch/x86/entry/vdso/vdso32-setup.c @@ -0,0 +1,86 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * (C) Copyright 2002 Linus Torvalds + * Portions based on the vdso-randomization code from exec-shield: + * Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar + * + * This file contains the needed initializations to support sysenter. + */ + +#include <linux/init.h> +#include <linux/smp.h> +#include <linux/kernel.h> +#include <linux/mm_types.h> +#include <linux/elf.h> + +#include <asm/processor.h> +#include <asm/vdso.h> + +#ifdef CONFIG_COMPAT_VDSO +#define VDSO_DEFAULT 0 +#else +#define VDSO_DEFAULT 1 +#endif + +/* + * Should the kernel map a VDSO page into processes and pass its + * address down to glibc upon exec()? + */ +unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT; + +static int __init vdso32_setup(char *s) +{ + vdso32_enabled = simple_strtoul(s, NULL, 0); + + if (vdso32_enabled > 1) { + pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n"); + vdso32_enabled = 0; + } + + return 1; +} + +/* + * For consistency, the argument vdso32=[012] affects the 32-bit vDSO + * behavior on both 64-bit and 32-bit kernels. + * On 32-bit kernels, vdso=[012] means the same thing. + */ +__setup("vdso32=", vdso32_setup); + +#ifdef CONFIG_X86_32 +__setup_param("vdso=", vdso_setup, vdso32_setup, 0); +#endif + + +#ifdef CONFIG_SYSCTL +#include <linux/sysctl.h> + +static const struct ctl_table vdso_table[] = { + { +#ifdef CONFIG_X86_64 + .procname = "vsyscall32", +#else + .procname = "vdso_enabled", +#endif + .data = &vdso32_enabled, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, +}; + +static __init int ia32_binfmt_init(void) +{ +#ifdef CONFIG_X86_64 + /* Register vsyscall32 into the ABI table */ + register_sysctl("abi", vdso_table); +#else + register_sysctl_init("vm", vdso_table); +#endif + return 0; +} +__initcall(ia32_binfmt_init); +#endif /* CONFIG_SYSCTL */ + diff --git a/arch/x86/entry/vdso/vdso32/.gitignore b/arch/x86/entry/vdso/vdso32/.gitignore new file mode 100644 index 000000000..516738484 --- /dev/null +++ b/arch/x86/entry/vdso/vdso32/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +vdso32.lds diff --git a/arch/x86/entry/vdso/vdso32/Makefile b/arch/x86/entry/vdso/vdso32/Makefile new file mode 100644 index 000000000..ab4b1f635 --- /dev/null +++ b/arch/x86/entry/vdso/vdso32/Makefile @@ -0,0 +1,29 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# 32-bit vDSO images for x86. +# + +# The vDSOs built in this directory +vdsos-y := 32 + +# Files to link into the vDSO: +vobjs-y := note.o vclock_gettime.o vgetcpu.o +vobjs-y += system_call.o sigreturn.o +vobjs-$(CONFIG_FUTEX_ROBUST_UNLOCK) += vfutex.o + +# Compilation flags +flags-y := -DBUILD_VDSO32 -m32 -mregparm=0 +flags-$(CONFIG_X86_64) += -include $(src)/fake_32bit_build.h +flags-remove-y := -m64 + +# Checker flags +CHECKFLAGS := $(subst -m64,-m32,$(CHECKFLAGS)) +CHECKFLAGS := $(subst -D__x86_64__,-D__i386__,$(CHECKFLAGS)) + +# The location of this include matters! +include $(src)/../common/Makefile.include + +# Linker options for the vdso +VDSO_LDFLAGS_32 := -m elf_i386 -soname linux-gate.so.1 + +$(obj)/vdso32.so.dbg: $(vobjs) diff --git a/arch/x86/entry/vdso/vdso32/fake_32bit_build.h b/arch/x86/entry/vdso/vdso32/fake_32bit_build.h new file mode 100644 index 000000000..bc3e54979 --- /dev/null +++ b/arch/x86/entry/vdso/vdso32/fake_32bit_build.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifdef CONFIG_X86_64 + +/* + * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel + * configuration + */ +#undef CONFIG_64BIT +#undef CONFIG_X86_64 +#undef CONFIG_COMPAT +#undef CONFIG_PGTABLE_LEVELS +#undef CONFIG_ILLEGAL_POINTER_VALUE +#undef CONFIG_SPARSEMEM_VMEMMAP +#undef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP +#undef CONFIG_NR_CPUS +#undef CONFIG_PARAVIRT_XXL + +#define CONFIG_X86_32 1 +#define CONFIG_PGTABLE_LEVELS 2 +#define CONFIG_PAGE_OFFSET 0 +#define CONFIG_ILLEGAL_POINTER_VALUE 0 +#define CONFIG_NR_CPUS 1 + +#define BUILD_VDSO32_64 + +#endif diff --git a/arch/x86/entry/vdso/vdso32/note.S b/arch/x86/entry/vdso/vdso32/note.S new file mode 100644 index 000000000..62d8aa51c --- /dev/null +++ b/arch/x86/entry/vdso/vdso32/note.S @@ -0,0 +1 @@ +#include "common/note.S" diff --git a/arch/x86/entry/vdso/vdso32/sigreturn.S b/arch/x86/entry/vdso/vdso32/sigreturn.S new file mode 100644 index 000000000..328bd3a4e --- /dev/null +++ b/arch/x86/entry/vdso/vdso32/sigreturn.S @@ -0,0 +1,84 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/linkage.h> +#include <asm/unistd_32.h> +#include <asm/dwarf2.h> +#include <asm/asm-offsets.h> + +.macro STARTPROC_SIGNAL_FRAME sc + CFI_STARTPROC simple + CFI_SIGNAL_FRAME + /* -4 as pretcode has already been popped */ + CFI_DEF_CFA esp, \sc - 4 + CFI_OFFSET eip, IA32_SIGCONTEXT_ip + CFI_OFFSET eax, IA32_SIGCONTEXT_ax + CFI_OFFSET ebx, IA32_SIGCONTEXT_bx + CFI_OFFSET ecx, IA32_SIGCONTEXT_cx + CFI_OFFSET edx, IA32_SIGCONTEXT_dx + CFI_OFFSET esp, IA32_SIGCONTEXT_sp + CFI_OFFSET ebp, IA32_SIGCONTEXT_bp + CFI_OFFSET esi, IA32_SIGCONTEXT_si + CFI_OFFSET edi, IA32_SIGCONTEXT_di + CFI_OFFSET es, IA32_SIGCONTEXT_es + CFI_OFFSET cs, IA32_SIGCONTEXT_cs + CFI_OFFSET ss, IA32_SIGCONTEXT_ss + CFI_OFFSET ds, IA32_SIGCONTEXT_ds + CFI_OFFSET eflags, IA32_SIGCONTEXT_flags +.endm + +/* + * WARNING: + * + * A bug in the libgcc unwinder as of at least gcc 15.2 (2026) means that + * the unwinder fails to recognize the signal frame flag. + * + * There is a hacky legacy fallback path in libgcc which ends up + * getting invoked instead. It happens to work as long as BOTH of the + * following conditions are true: + * + * 1. There is at least one byte before the each of the sigreturn + * functions which falls outside any function. This is enforced by + * an explicit nop instruction before the ALIGN. + * 2. The code sequences between the entry point up to and including + * the int $0x80 below need to match EXACTLY. Do not change them + * in any way. The exact byte sequences are: + * + * __kernel_sigreturn: + * 0: 58 pop %eax + * 1: b8 77 00 00 00 mov $0x77,%eax + * 6: cd 80 int $0x80 + * + * __kernel_rt_sigreturn: + * 0: b8 ad 00 00 00 mov $0xad,%eax + * 5: cd 80 int $0x80 + * + * For details, see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124050 + */ + .text + .globl __kernel_sigreturn + .type __kernel_sigreturn,@function + nop /* libgcc hack: see comment above */ + ALIGN +__kernel_sigreturn: + STARTPROC_SIGNAL_FRAME IA32_SIGFRAME_sigcontext + popl %eax + CFI_ADJUST_CFA_OFFSET -4 + movl $__NR_sigreturn, %eax + int $0x80 +SYM_INNER_LABEL(vdso32_sigreturn_landing_pad, SYM_L_GLOBAL) + ud2a + CFI_ENDPROC + .size __kernel_sigreturn,.-__kernel_sigreturn + + .globl __kernel_rt_sigreturn + .type __kernel_rt_sigreturn,@function + nop /* libgcc hack: see comment above */ + ALIGN +__kernel_rt_sigreturn: + STARTPROC_SIGNAL_FRAME IA32_RT_SIGFRAME_sigcontext + movl $__NR_rt_sigreturn, %eax + int $0x80 +SYM_INNER_LABEL(vdso32_rt_sigreturn_landing_pad, SYM_L_GLOBAL) + ud2a + CFI_ENDPROC + .size __kernel_rt_sigreturn,.-__kernel_rt_sigreturn + .previous diff --git a/arch/x86/entry/vdso/vdso32/system_call.S b/arch/x86/entry/vdso/vdso32/system_call.S new file mode 100644 index 000000000..9157cf9c5 --- /dev/null +++ b/arch/x86/entry/vdso/vdso32/system_call.S @@ -0,0 +1,91 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * AT_SYSINFO entry point +*/ + +#include <linux/linkage.h> +#include <asm/dwarf2.h> +#include <asm/cpufeatures.h> +#include <asm/alternative.h> + + .text + .globl __kernel_vsyscall + .type __kernel_vsyscall,@function + ALIGN +__kernel_vsyscall: + CFI_STARTPROC + + /* + * If using int $0x80, there is no reason to muck about with the + * stack here. Unfortunately just overwriting the push instructions + * would mess up the CFI annotations, but it is only a 3-byte + * NOP in that case. This could be avoided by patching the + * vdso symbol table (not the code) and entry point, but that + * would a fair bit of tooling work or by simply compiling + * two different vDSO images, but that doesn't seem worth it. + */ + ALTERNATIVE "int $0x80; ret", "", X86_FEATURE_SYSFAST32 + + /* + * Reshuffle regs so that all of any of the entry instructions + * will preserve enough state. + * + * A really nice entry sequence would be: + * pushl %edx + * pushl %ecx + * movl %esp, %ecx + * + * Unfortunately, naughty Android versions between July and December + * 2015 actually hardcode the traditional Linux SYSENTER entry + * sequence. That is severely broken for a number of reasons (ask + * anyone with an AMD CPU, for example). Nonetheless, we try to keep + * it working approximately as well as it ever worked. + * + * This link may elucidate some of the history: + * https://android-review.googlesource.com/#/q/Iac3295376d61ef83e713ac9b528f3b50aa780cd7 + * personally, I find it hard to understand what's going on there. + * + * Note to future user developers: DO NOT USE SYSENTER IN YOUR CODE. + * Execute an indirect call to the address in the AT_SYSINFO auxv + * entry. That is the ONLY correct way to make a fast 32-bit system + * call on Linux. (Open-coding int $0x80 is also fine, but it's + * slow.) + */ + pushl %ecx + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET ecx, 0 + pushl %edx + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET edx, 0 + pushl %ebp + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET ebp, 0 + + #define SYSENTER_SEQUENCE "movl %esp, %ebp; sysenter" + #define SYSCALL_SEQUENCE "movl %ecx, %ebp; syscall" + + ALTERNATIVE SYSENTER_SEQUENCE, SYSCALL_SEQUENCE, X86_FEATURE_SYSCALL32 + + /* Re-enter using int $0x80 */ + int $0x80 +SYM_INNER_LABEL(int80_landing_pad, SYM_L_GLOBAL) + + /* + * Restore EDX and ECX in case they were clobbered. EBP is not + * clobbered (the kernel restores it), but it's cleaner and + * probably faster to pop it than to adjust ESP using addl. + */ + popl %ebp + CFI_RESTORE ebp + CFI_ADJUST_CFA_OFFSET -4 + popl %edx + CFI_RESTORE edx + CFI_ADJUST_CFA_OFFSET -4 + popl %ecx + CFI_RESTORE ecx + CFI_ADJUST_CFA_OFFSET -4 + RET + CFI_ENDPROC + + .size __kernel_vsyscall,.-__kernel_vsyscall + .previous diff --git a/arch/x86/entry/vdso/vdso32/vclock_gettime.c b/arch/x86/entry/vdso/vdso32/vclock_gettime.c new file mode 100644 index 000000000..1481f0021 --- /dev/null +++ b/arch/x86/entry/vdso/vdso32/vclock_gettime.c @@ -0,0 +1 @@ +#include "common/vclock_gettime.c" diff --git a/arch/x86/entry/vdso/vdso32/vdso32.lds.S b/arch/x86/entry/vdso/vdso32/vdso32.lds.S new file mode 100644 index 000000000..00629192d --- /dev/null +++ b/arch/x86/entry/vdso/vdso32/vdso32.lds.S @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Linker script for 32-bit vDSO. + * We #include the file to define the layout details. + * + * This file defines the version script giving the user-exported symbols in + * the DSO. + */ + +#include <asm/page.h> + +#define BUILD_VDSO32 + +#include "common/vdso-layout.lds.S" + +/* The ELF entry point can be used to set the AT_SYSINFO value. */ +ENTRY(__kernel_vsyscall); + +/* + * This controls what userland symbols we export from the vDSO. + */ +VERSION +{ + LINUX_2.6 { + global: +#ifdef CONFIG_COMPAT_32BIT_TIME + __vdso_clock_gettime; + __vdso_gettimeofday; + __vdso_time; + __vdso_clock_getres; +#endif /* CONFIG_COMPAT_32BIT_TIME */ + __vdso_clock_gettime64; + __vdso_clock_getres_time64; + __vdso_getcpu; +#ifdef CONFIG_FUTEX_ROBUST_UNLOCK + __vdso_futex_robust_list32_try_unlock; +#endif + }; + + LINUX_2.5 { + global: + __kernel_vsyscall; + __kernel_sigreturn; + __kernel_rt_sigreturn; + local: *; + }; +} diff --git a/arch/x86/entry/vdso/vdso32/vfutex.c b/arch/x86/entry/vdso/vdso32/vfutex.c new file mode 100644 index 000000000..940a6ee30 --- /dev/null +++ b/arch/x86/entry/vdso/vdso32/vfutex.c @@ -0,0 +1 @@ +#include "common/vfutex.c" diff --git a/arch/x86/entry/vdso/vdso32/vgetcpu.c b/arch/x86/entry/vdso/vdso32/vgetcpu.c new file mode 100644 index 000000000..00cc8325a --- /dev/null +++ b/arch/x86/entry/vdso/vdso32/vgetcpu.c @@ -0,0 +1 @@ +#include "common/vgetcpu.c" diff --git a/arch/x86/entry/vdso/vdso64/Makefile b/arch/x86/entry/vdso/vdso64/Makefile new file mode 100644 index 000000000..7c0790065 --- /dev/null +++ b/arch/x86/entry/vdso/vdso64/Makefile @@ -0,0 +1,47 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# 64-bit vDSO images for x86. +# + +# The vDSOs built in this directory +vdsos-y := 64 +vdsos-$(CONFIG_X86_X32_ABI) += x32 + +# Files to link into the vDSO: +vobjs-y := note.o vclock_gettime.o vgetcpu.o +vobjs-y += vgetrandom.o vgetrandom-chacha.o +vobjs-$(CONFIG_X86_SGX) += vsgx.o +vobjs-$(CONFIG_FUTEX_ROBUST_UNLOCK) += vfutex.o + +# Compilation flags +flags-y := -DBUILD_VDSO64 -m64 -mcmodel=small + +# The location of this include matters! +include $(src)/../common/Makefile.include + +# +# X32 processes use x32 vDSO to access 64bit kernel data. +# +# Build x32 vDSO image: +# 1. Compile x32 vDSO as 64bit. +# 2. Convert object files to x32. +# 3. Build x32 VDSO image with x32 objects, which contains 64bit codes +# so that it can reach 64bit address space with 64bit pointers. +# + +# Convert 64bit object file to x32 for x32 vDSO. +quiet_cmd_x32 = X32 $@ + cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@ + +$(obj)/%-x32.o: $(obj)/%.o FORCE + $(call if_changed,x32) + +vobjsx32 = $(patsubst %.o,%-x32.o,$(vobjs)) +targets += $(patsubst %.o,%-x32.o,$(vobjs-y)) + +# Linker options for the vdso +VDSO_LDFLAGS_64 := -m elf_x86_64 -soname linux-vdso.so.1 -z max-page-size=4096 +VDSO_LDFLAGS_x32 := $(subst elf_x86_64,elf32_x86_64,$(VDSO_LDFLAGS_64)) + +$(obj)/vdso64.so.dbg: $(vobjs) +$(obj)/vdsox32.so.dbg: $(vobjsx32) diff --git a/arch/x86/entry/vdso/vdso64/note.S b/arch/x86/entry/vdso/vdso64/note.S new file mode 100644 index 000000000..62d8aa51c --- /dev/null +++ b/arch/x86/entry/vdso/vdso64/note.S @@ -0,0 +1 @@ +#include "common/note.S" diff --git a/arch/x86/entry/vdso/vdso64/vclock_gettime.c b/arch/x86/entry/vdso/vdso64/vclock_gettime.c new file mode 100644 index 000000000..1481f0021 --- /dev/null +++ b/arch/x86/entry/vdso/vdso64/vclock_gettime.c @@ -0,0 +1 @@ +#include "common/vclock_gettime.c" diff --git a/arch/x86/entry/vdso/vdso64/vdso64.lds.S b/arch/x86/entry/vdso/vdso64/vdso64.lds.S new file mode 100644 index 000000000..4a72122da --- /dev/null +++ b/arch/x86/entry/vdso/vdso64/vdso64.lds.S @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Linker script for 64-bit vDSO. + * We #include the file to define the layout details. + * + * This file defines the version script giving the user-exported symbols in + * the DSO. + */ + +#define BUILD_VDSO64 + +#include "common/vdso-layout.lds.S" + +/* + * This controls what userland symbols we export from the vDSO. + */ +VERSION { + LINUX_2.6 { + global: + clock_gettime; + __vdso_clock_gettime; + gettimeofday; + __vdso_gettimeofday; + getcpu; + __vdso_getcpu; + time; + __vdso_time; + clock_getres; + __vdso_clock_getres; +#ifdef CONFIG_X86_SGX + __vdso_sgx_enter_enclave; +#endif + getrandom; + __vdso_getrandom; + +#ifdef CONFIG_FUTEX_ROBUST_UNLOCK + __vdso_futex_robust_list64_try_unlock; +#ifdef CONFIG_COMPAT + __vdso_futex_robust_list32_try_unlock; +#endif +#endif + local: *; + }; +} diff --git a/arch/x86/entry/vdso/vdso64/vdsox32.lds.S b/arch/x86/entry/vdso/vdso64/vdsox32.lds.S new file mode 100644 index 000000000..b917dc69f --- /dev/null +++ b/arch/x86/entry/vdso/vdso64/vdsox32.lds.S @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Linker script for x32 vDSO. + * We #include the file to define the layout details. + * + * This file defines the version script giving the user-exported symbols in + * the DSO. + */ + +#define BUILD_VDSOX32 + +#include "common/vdso-layout.lds.S" + +/* + * This controls what userland symbols we export from the vDSO. + */ +VERSION { + LINUX_2.6 { + global: + __vdso_clock_gettime; + __vdso_gettimeofday; + __vdso_getcpu; + __vdso_time; + __vdso_clock_getres; + +#ifdef CONFIG_FUTEX_ROBUST_UNLOCK + __vdso_futex_robust_list64_try_unlock; +#ifdef CONFIG_COMPAT + __vdso_futex_robust_list32_try_unlock; +#endif +#endif + local: *; + }; +} diff --git a/arch/x86/entry/vdso/vdso64/vfutex.c b/arch/x86/entry/vdso/vdso64/vfutex.c new file mode 100644 index 000000000..940a6ee30 --- /dev/null +++ b/arch/x86/entry/vdso/vdso64/vfutex.c @@ -0,0 +1 @@ +#include "common/vfutex.c" diff --git a/arch/x86/entry/vdso/vdso64/vgetcpu.c b/arch/x86/entry/vdso/vdso64/vgetcpu.c new file mode 100644 index 000000000..00cc8325a --- /dev/null +++ b/arch/x86/entry/vdso/vdso64/vgetcpu.c @@ -0,0 +1 @@ +#include "common/vgetcpu.c" diff --git a/arch/x86/entry/vdso/vdso64/vgetrandom-chacha.S b/arch/x86/entry/vdso/vdso64/vgetrandom-chacha.S new file mode 100644 index 000000000..bcba5639b --- /dev/null +++ b/arch/x86/entry/vdso/vdso64/vgetrandom-chacha.S @@ -0,0 +1,178 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2022-2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + */ + +#include <linux/linkage.h> +#include <asm/frame.h> + +.section .rodata, "a" +.align 16 +CONSTANTS: .octa 0x6b20657479622d323320646e61707865 +.text + +/* + * Very basic SSE2 implementation of ChaCha20. Produces a given positive number + * of blocks of output with a nonce of 0, taking an input key and 8-byte + * counter. Importantly does not spill to the stack. Its arguments are: + * + * rdi: output bytes + * rsi: 32-byte key input + * rdx: 8-byte counter input/output + * rcx: number of 64-byte blocks to write to output + */ +SYM_FUNC_START(__arch_chacha20_blocks_nostack) + +.set output, %rdi +.set key, %rsi +.set counter, %rdx +.set nblocks, %rcx +.set i, %al +/* xmm registers are *not* callee-save. */ +.set temp, %xmm0 +.set state0, %xmm1 +.set state1, %xmm2 +.set state2, %xmm3 +.set state3, %xmm4 +.set copy0, %xmm5 +.set copy1, %xmm6 +.set copy2, %xmm7 +.set copy3, %xmm8 +.set one, %xmm9 + + /* copy0 = "expand 32-byte k" */ + movaps CONSTANTS(%rip),copy0 + /* copy1,copy2 = key */ + movups 0x00(key),copy1 + movups 0x10(key),copy2 + /* copy3 = counter || zero nonce */ + movq 0x00(counter),copy3 + /* one = 1 || 0 */ + movq $1,%rax + movq %rax,one + +.Lblock: + /* state0,state1,state2,state3 = copy0,copy1,copy2,copy3 */ + movdqa copy0,state0 + movdqa copy1,state1 + movdqa copy2,state2 + movdqa copy3,state3 + + movb $10,i +.Lpermute: + /* state0 += state1, state3 = rotl32(state3 ^ state0, 16) */ + paddd state1,state0 + pxor state0,state3 + movdqa state3,temp + pslld $16,temp + psrld $16,state3 + por temp,state3 + + /* state2 += state3, state1 = rotl32(state1 ^ state2, 12) */ + paddd state3,state2 + pxor state2,state1 + movdqa state1,temp + pslld $12,temp + psrld $20,state1 + por temp,state1 + + /* state0 += state1, state3 = rotl32(state3 ^ state0, 8) */ + paddd state1,state0 + pxor state0,state3 + movdqa state3,temp + pslld $8,temp + psrld $24,state3 + por temp,state3 + + /* state2 += state3, state1 = rotl32(state1 ^ state2, 7) */ + paddd state3,state2 + pxor state2,state1 + movdqa state1,temp + pslld $7,temp + psrld $25,state1 + por temp,state1 + + /* state1[0,1,2,3] = state1[1,2,3,0] */ + pshufd $0x39,state1,state1 + /* state2[0,1,2,3] = state2[2,3,0,1] */ + pshufd $0x4e,state2,state2 + /* state3[0,1,2,3] = state3[3,0,1,2] */ + pshufd $0x93,state3,state3 + + /* state0 += state1, state3 = rotl32(state3 ^ state0, 16) */ + paddd state1,state0 + pxor state0,state3 + movdqa state3,temp + pslld $16,temp + psrld $16,state3 + por temp,state3 + + /* state2 += state3, state1 = rotl32(state1 ^ state2, 12) */ + paddd state3,state2 + pxor state2,state1 + movdqa state1,temp + pslld $12,temp + psrld $20,state1 + por temp,state1 + + /* state0 += state1, state3 = rotl32(state3 ^ state0, 8) */ + paddd state1,state0 + pxor state0,state3 + movdqa state3,temp + pslld $8,temp + psrld $24,state3 + por temp,state3 + + /* state2 += state3, state1 = rotl32(state1 ^ state2, 7) */ + paddd state3,state2 + pxor state2,state1 + movdqa state1,temp + pslld $7,temp + psrld $25,state1 + por temp,state1 + + /* state1[0,1,2,3] = state1[3,0,1,2] */ + pshufd $0x93,state1,state1 + /* state2[0,1,2,3] = state2[2,3,0,1] */ + pshufd $0x4e,state2,state2 + /* state3[0,1,2,3] = state3[1,2,3,0] */ + pshufd $0x39,state3,state3 + + decb i + jnz .Lpermute + + /* output0 = state0 + copy0 */ + paddd copy0,state0 + movups state0,0x00(output) + /* output1 = state1 + copy1 */ + paddd copy1,state1 + movups state1,0x10(output) + /* output2 = state2 + copy2 */ + paddd copy2,state2 + movups state2,0x20(output) + /* output3 = state3 + copy3 */ + paddd copy3,state3 + movups state3,0x30(output) + + /* ++copy3.counter */ + paddq one,copy3 + + /* output += 64, --nblocks */ + addq $64,output + decq nblocks + jnz .Lblock + + /* counter = copy3.counter */ + movq copy3,0x00(counter) + + /* Zero out the potentially sensitive regs, in case nothing uses these again. */ + pxor state0,state0 + pxor state1,state1 + pxor state2,state2 + pxor state3,state3 + pxor copy1,copy1 + pxor copy2,copy2 + pxor temp,temp + + ret +SYM_FUNC_END(__arch_chacha20_blocks_nostack) diff --git a/arch/x86/entry/vdso/vdso64/vgetrandom.c b/arch/x86/entry/vdso/vdso64/vgetrandom.c new file mode 100644 index 000000000..6a95d36b1 --- /dev/null +++ b/arch/x86/entry/vdso/vdso64/vgetrandom.c @@ -0,0 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2022-2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + */ +#include <linux/types.h> + +#include "lib/vdso/getrandom.c" + +ssize_t __vdso_getrandom(void *buffer, size_t len, unsigned int flags, void *opaque_state, size_t opaque_len) +{ + return __cvdso_getrandom(buffer, len, flags, opaque_state, opaque_len); +} + +ssize_t getrandom(void *, size_t, unsigned int, void *, size_t) + __attribute__((weak, alias("__vdso_getrandom"))); diff --git a/arch/x86/entry/vdso/vdso64/vsgx.S b/arch/x86/entry/vdso/vdso64/vsgx.S new file mode 100644 index 000000000..37a3d4c02 --- /dev/null +++ b/arch/x86/entry/vdso/vdso64/vsgx.S @@ -0,0 +1,150 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include <linux/linkage.h> +#include <asm/errno.h> +#include <asm/enclu.h> + +#include "extable.h" + +/* Relative to %rbp. */ +#define SGX_ENCLAVE_OFFSET_OF_RUN 16 + +/* The offsets relative to struct sgx_enclave_run. */ +#define SGX_ENCLAVE_RUN_TCS 0 +#define SGX_ENCLAVE_RUN_LEAF 8 +#define SGX_ENCLAVE_RUN_EXCEPTION_VECTOR 12 +#define SGX_ENCLAVE_RUN_EXCEPTION_ERROR_CODE 14 +#define SGX_ENCLAVE_RUN_EXCEPTION_ADDR 16 +#define SGX_ENCLAVE_RUN_USER_HANDLER 24 +#define SGX_ENCLAVE_RUN_USER_DATA 32 /* not used */ +#define SGX_ENCLAVE_RUN_RESERVED_START 40 +#define SGX_ENCLAVE_RUN_RESERVED_END 256 + +.code64 +.section .text, "ax" + +SYM_FUNC_START(__vdso_sgx_enter_enclave) + /* Prolog */ + .cfi_startproc + push %rbp + .cfi_adjust_cfa_offset 8 + .cfi_rel_offset %rbp, 0 + mov %rsp, %rbp + .cfi_def_cfa_register %rbp + push %rbx + .cfi_rel_offset %rbx, -8 + + mov %ecx, %eax +.Lenter_enclave: + /* EENTER <= function <= ERESUME */ + cmp $EENTER, %eax + jb .Linvalid_input + cmp $ERESUME, %eax + ja .Linvalid_input + + mov SGX_ENCLAVE_OFFSET_OF_RUN(%rbp), %rcx + + /* Validate that the reserved area contains only zeros. */ + mov $SGX_ENCLAVE_RUN_RESERVED_START, %rbx +1: + cmpq $0, (%rcx, %rbx) + jne .Linvalid_input + add $8, %rbx + cmpq $SGX_ENCLAVE_RUN_RESERVED_END, %rbx + jne 1b + + /* Load TCS and AEP */ + mov SGX_ENCLAVE_RUN_TCS(%rcx), %rbx + lea .Lasync_exit_pointer(%rip), %rcx + + /* Single ENCLU serving as both EENTER and AEP (ERESUME) */ +.Lasync_exit_pointer: +.Lenclu_eenter_eresume: + enclu + + /* EEXIT jumps here unless the enclave is doing something fancy. */ + mov SGX_ENCLAVE_OFFSET_OF_RUN(%rbp), %rbx + + /* Set exit_reason. */ + movl $EEXIT, SGX_ENCLAVE_RUN_LEAF(%rbx) + + /* Invoke userspace's exit handler if one was provided. */ +.Lhandle_exit: + cmpq $0, SGX_ENCLAVE_RUN_USER_HANDLER(%rbx) + jne .Linvoke_userspace_handler + + /* Success, in the sense that ENCLU was attempted. */ + xor %eax, %eax + +.Lout: + pop %rbx + leave + .cfi_def_cfa %rsp, 8 + RET + + /* The out-of-line code runs with the pre-leave stack frame. */ + .cfi_def_cfa %rbp, 16 + +.Linvalid_input: + mov $(-EINVAL), %eax + jmp .Lout + +.Lhandle_exception: + mov SGX_ENCLAVE_OFFSET_OF_RUN(%rbp), %rbx + + /* Set the exception info. */ + mov %eax, (SGX_ENCLAVE_RUN_LEAF)(%rbx) + mov %di, (SGX_ENCLAVE_RUN_EXCEPTION_VECTOR)(%rbx) + mov %si, (SGX_ENCLAVE_RUN_EXCEPTION_ERROR_CODE)(%rbx) + mov %rdx, (SGX_ENCLAVE_RUN_EXCEPTION_ADDR)(%rbx) + jmp .Lhandle_exit + +.Linvoke_userspace_handler: + /* Pass the untrusted RSP (at exit) to the callback via %rcx. */ + mov %rsp, %rcx + + /* Save struct sgx_enclave_exception %rbx is about to be clobbered. */ + mov %rbx, %rax + + /* Save the untrusted RSP offset in %rbx (non-volatile register). */ + mov %rsp, %rbx + and $0xf, %rbx + + /* + * Align stack per x86_64 ABI. Note, %rsp needs to be 16-byte aligned + * _after_ pushing the parameters on the stack, hence the bonus push. + */ + and $-0x10, %rsp + push %rax + + /* Push struct sgx_enclave_exception as a param to the callback. */ + push %rax + + /* Clear RFLAGS.DF per x86_64 ABI */ + cld + + /* + * Load the callback pointer to %rax and lfence for LVI (load value + * injection) protection before making the call. + */ + mov SGX_ENCLAVE_RUN_USER_HANDLER(%rax), %rax + lfence + call *%rax + + /* Undo the post-exit %rsp adjustment. */ + lea 0x10(%rsp, %rbx), %rsp + + /* + * If the return from callback is zero or negative, return immediately, + * else re-execute ENCLU with the positive return value interpreted as + * the requested ENCLU function. + */ + cmp $0, %eax + jle .Lout + jmp .Lenter_enclave + + .cfi_endproc + +_ASM_VDSO_EXTABLE_HANDLE(.Lenclu_eenter_eresume, .Lhandle_exception) + +SYM_FUNC_END(__vdso_sgx_enter_enclave) diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c new file mode 100644 index 000000000..18dfd80a8 --- /dev/null +++ b/arch/x86/entry/vdso/vma.c @@ -0,0 +1,306 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2007 Andi Kleen, SUSE Labs. + * + * This contains most of the x86 vDSO kernel-side code. + */ +#include <linux/mm.h> +#include <linux/err.h> +#include <linux/futex.h> +#include <linux/sched.h> +#include <linux/sched/task_stack.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/random.h> +#include <linux/elf.h> +#include <linux/cpu.h> +#include <linux/ptrace.h> +#include <linux/vdso_datastore.h> + +#include <asm/pvclock.h> +#include <asm/vgtod.h> +#include <asm/proto.h> +#include <asm/vdso.h> +#include <asm/tlb.h> +#include <asm/page.h> +#include <asm/desc.h> +#include <asm/cpufeature.h> +#include <asm/vdso/vsyscall.h> +#include <clocksource/hyperv_timer.h> + +static_assert(VDSO_NR_PAGES + VDSO_NR_VCLOCK_PAGES == __VDSO_PAGES); + +unsigned int vclocks_used __read_mostly; + +#if defined(CONFIG_X86_64) +unsigned int __read_mostly vdso64_enabled = 1; +#endif + +int __init init_vdso_image(const struct vdso_image *image) +{ + BUILD_BUG_ON(VDSO_CLOCKMODE_MAX >= 32); + BUG_ON(image->size % PAGE_SIZE != 0); + + apply_alternatives((struct alt_instr *)(image->data + image->alt), + (struct alt_instr *)(image->data + image->alt + + image->alt_len)); + + return 0; +} + +struct linux_binprm; + +static vm_fault_t vdso_fault(const struct vm_special_mapping *sm, + struct vm_area_struct *vma, struct vm_fault *vmf) +{ + const struct vdso_image *image = vma->vm_mm->context.vdso_image; + + if (!image || (vmf->pgoff << PAGE_SHIFT) >= image->size) + return VM_FAULT_SIGBUS; + + vmf->page = virt_to_page(image->data + (vmf->pgoff << PAGE_SHIFT)); + get_page(vmf->page); + return 0; +} + +static void vdso_fix_landing(const struct vdso_image *image, + struct vm_area_struct *new_vma) +{ + struct pt_regs *regs = current_pt_regs(); + unsigned long ipoffset = regs->ip - + (unsigned long)current->mm->context.vdso; + + if (ipoffset < image->size) + regs->ip = new_vma->vm_start + ipoffset; +} + +#ifdef CONFIG_FUTEX_ROBUST_UNLOCK +static void vdso_futex_robust_unlock_update_ips(void) +{ + const struct vdso_image *image = current->mm->context.vdso_image; + unsigned long vdso = (unsigned long) current->mm->context.vdso; + struct futex_mm_data *fd = ¤t->mm->futex; + unsigned int idx = 0; + + futex_reset_cs_ranges(fd); + +#ifdef CONFIG_X86_64 + futex_set_vdso_cs_range(fd, idx, vdso + image->sym___futex_list64_try_unlock_cs_start, + vdso + image->sym___futex_list64_try_unlock_cs_end, false); + idx++; +#endif /* CONFIG_X86_64 */ + +#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT) + futex_set_vdso_cs_range(fd, idx, vdso + image->sym___futex_list32_try_unlock_cs_start, + vdso + image->sym___futex_list32_try_unlock_cs_end, true); +#endif /* CONFIG_X86_32 || CONFIG_COMPAT */ +} +#else +static inline void vdso_futex_robust_unlock_update_ips(void) { } +#endif + +static int vdso_mremap(const struct vm_special_mapping *sm, + struct vm_area_struct *new_vma) +{ + const struct vdso_image *image = current->mm->context.vdso_image; + + vdso_fix_landing(image, new_vma); + current->mm->context.vdso = (void __user *)new_vma->vm_start; + vdso_futex_robust_unlock_update_ips(); + + return 0; +} + +static vm_fault_t vvar_vclock_fault(const struct vm_special_mapping *sm, + struct vm_area_struct *vma, struct vm_fault *vmf) +{ + switch (vmf->pgoff) { + case VDSO_PAGE_PVCLOCK_OFFSET: + { + struct pvclock_vsyscall_time_info *pvti = + pvclock_get_pvti_cpu0_va(); + + if (pvti && vclock_was_used(VDSO_CLOCKMODE_PVCLOCK)) + return vmf_insert_pfn_prot(vma, vmf->address, + __pa(pvti) >> PAGE_SHIFT, + pgprot_decrypted(vma->vm_page_prot)); + break; + } + case VDSO_PAGE_HVCLOCK_OFFSET: + { + unsigned long pfn = hv_get_tsc_pfn(); + if (pfn && vclock_was_used(VDSO_CLOCKMODE_HVCLOCK)) + return vmf_insert_pfn(vma, vmf->address, pfn); + break; + } + } + + return VM_FAULT_SIGBUS; +} + +static const struct vm_special_mapping vdso_mapping = { + .name = "[vdso]", + .fault = vdso_fault, + .mremap = vdso_mremap, +}; +static const struct vm_special_mapping vvar_vclock_mapping = { + .name = "[vvar_vclock]", + .fault = vvar_vclock_fault, +}; + +/* + * Add vdso and vvar mappings to current process. + * @image - blob to map + * @addr - request a specific address (zero to map at free addr) + */ +static int map_vdso(const struct vdso_image *image, unsigned long addr) +{ + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + unsigned long text_start; + int ret = 0; + + if (mmap_write_lock_killable(mm)) + return -EINTR; + + addr = get_unmapped_area(NULL, addr, + image->size + __VDSO_PAGES * PAGE_SIZE, 0, 0); + if (IS_ERR_VALUE(addr)) { + ret = addr; + goto up_fail; + } + + text_start = addr + __VDSO_PAGES * PAGE_SIZE; + + /* + * MAYWRITE to allow gdb to COW and set breakpoints + */ + vma = _install_special_mapping(mm, + text_start, + image->size, + VM_READ|VM_EXEC| + VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC| + VM_SEALED_SYSMAP, + &vdso_mapping); + + if (IS_ERR(vma)) { + ret = PTR_ERR(vma); + goto up_fail; + } + + vma = vdso_install_vvar_mapping(mm, addr); + if (IS_ERR(vma)) { + ret = PTR_ERR(vma); + do_munmap(mm, text_start, image->size, NULL); + goto up_fail; + } + + vma = _install_special_mapping(mm, + VDSO_VCLOCK_PAGES_START(addr), + VDSO_NR_VCLOCK_PAGES * PAGE_SIZE, + VM_READ|VM_MAYREAD|VM_IO|VM_DONTDUMP| + VM_PFNMAP|VM_SEALED_SYSMAP, + &vvar_vclock_mapping); + + if (IS_ERR(vma)) { + ret = PTR_ERR(vma); + do_munmap(mm, text_start, image->size, NULL); + do_munmap(mm, addr, VDSO_NR_PAGES * PAGE_SIZE, NULL); + goto up_fail; + } + + current->mm->context.vdso = (void __user *)text_start; + current->mm->context.vdso_image = image; + + vdso_futex_robust_unlock_update_ips(); + +up_fail: + mmap_write_unlock(mm); + return ret; +} + +int map_vdso_once(const struct vdso_image *image, unsigned long addr) +{ + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + VMA_ITERATOR(vmi, mm, 0); + + mmap_write_lock(mm); + /* + * Check if we have already mapped vdso blob - fail to prevent + * abusing from userspace install_special_mapping, which may + * not do accounting and rlimit right. + * We could search vma near context.vdso, but it's a slowpath, + * so let's explicitly check all VMAs to be completely sure. + */ + for_each_vma(vmi, vma) { + if (vma_is_special_mapping(vma, &vdso_mapping) || + vma_is_special_mapping(vma, &vdso_vvar_mapping) || + vma_is_special_mapping(vma, &vvar_vclock_mapping)) { + mmap_write_unlock(mm); + return -EEXIST; + } + } + mmap_write_unlock(mm); + + return map_vdso(image, addr); +} + +static int load_vdso32(void) +{ + if (vdso32_enabled != 1) /* Other values all mean "disabled" */ + return 0; + + return map_vdso(&vdso32_image, 0); +} + +int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) +{ + if (IS_ENABLED(CONFIG_X86_64)) { + if (!vdso64_enabled) + return 0; + + return map_vdso(&vdso64_image, 0); + } + + return load_vdso32(); +} + +#ifdef CONFIG_COMPAT +int compat_arch_setup_additional_pages(struct linux_binprm *bprm, + int uses_interp, bool x32) +{ + if (IS_ENABLED(CONFIG_X86_X32_ABI) && x32) { + if (!vdso64_enabled) + return 0; + return map_vdso(&vdsox32_image, 0); + } + + if (IS_ENABLED(CONFIG_IA32_EMULATION)) + return load_vdso32(); + + return 0; +} +#endif + +bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs) +{ + const struct vdso_image *image = current->mm->context.vdso_image; + unsigned long vdso = (unsigned long) current->mm->context.vdso; + + if (in_ia32_syscall() && image == &vdso32_image) { + if (regs->ip == vdso + image->sym_vdso32_sigreturn_landing_pad || + regs->ip == vdso + image->sym_vdso32_rt_sigreturn_landing_pad) + return true; + } + return false; +} + +#ifdef CONFIG_X86_64 +static __init int vdso_setup(char *s) +{ + vdso64_enabled = simple_strtoul(s, NULL, 0); + return 1; +} +__setup("vdso=", vdso_setup); +#endif /* CONFIG_X86_64 */ |
