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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-13 19:33:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-13 19:33:23 -0700 |
| commit | a5131c3fdf2608f1c15f3809e201cf540eb28489 (patch) | |
| tree | 52d1dc332caa105adba5eb384101fa944d82bdc4 | |
| parent | 5f487cd8290f3ae742cee18d92f2bb0063dc471c (diff) | |
| parent | 2883f01ec37dd8668e7222dfdb5980c86fdfe277 (diff) | |
Merge tag 'x86-shstk-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 shadow stacks from Ingo Molnar:
"Enable shadow stacks for x32.
While we normally don't do such feature-enabling for 32-bit anymore,
this change is small, straightforward & tested on upstream glibc"
* tag 'x86-shstk-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/shstk: Enable shadow stacks for x32
| -rw-r--r-- | arch/x86/entry/syscalls/syscall_64.tbl | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/shstk.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/signal_64.c | 6 |
3 files changed, 9 insertions, 3 deletions
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 7e8d46f4147f..cc78226ffc35 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -374,7 +374,7 @@ 450 common set_mempolicy_home_node sys_set_mempolicy_home_node 451 common cachestat sys_cachestat 452 common fchmodat2 sys_fchmodat2 -453 64 map_shadow_stack sys_map_shadow_stack +453 common map_shadow_stack sys_map_shadow_stack 454 common futex_wake sys_futex_wake 455 common futex_wait sys_futex_wait 456 common futex_requeue sys_futex_requeue diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c index 59e15dd8d0f8..6f1e9883f074 100644 --- a/arch/x86/kernel/shstk.c +++ b/arch/x86/kernel/shstk.c @@ -163,8 +163,8 @@ static int shstk_setup(void) if (features_enabled(ARCH_SHSTK_SHSTK)) return 0; - /* Also not supported for 32 bit and x32 */ - if (!cpu_feature_enabled(X86_FEATURE_USER_SHSTK) || in_32bit_syscall()) + /* Also not supported for 32 bit */ + if (!cpu_feature_enabled(X86_FEATURE_USER_SHSTK) || in_ia32_syscall()) return -EOPNOTSUPP; size = adjust_shstk_size(0); diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c index 23d8aaf8d9fd..8a94053c5444 100644 --- a/arch/x86/kernel/signal_64.c +++ b/arch/x86/kernel/signal_64.c @@ -315,6 +315,9 @@ int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs) uc_flags = frame_uc_flags(regs); + if (setup_signal_shadow_stack(ksig)) + return -EFAULT; + if (!user_access_begin(frame, sizeof(*frame))) return -EFAULT; @@ -377,6 +380,9 @@ COMPAT_SYSCALL_DEFINE0(x32_rt_sigreturn) if (!restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags)) goto badframe; + if (restore_signal_shadow_stack()) + goto badframe; + if (compat_restore_altstack(&frame->uc.uc_stack)) goto badframe; |