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authorLinus Torvalds <torvalds@linux-foundation.org>2024-05-14 05:33:23 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2024-05-14 05:33:23 +0300
commita5131c3fdf2608f1c15f3809e201cf540eb28489 (patch)
tree52d1dc332caa105adba5eb384101fa944d82bdc4 /arch
parent5f487cd8290f3ae742cee18d92f2bb0063dc471c (diff)
parent2883f01ec37dd8668e7222dfdb5980c86fdfe277 (diff)
downloadlinux-a5131c3fdf2608f1c15f3809e201cf540eb28489.tar.xz
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
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/entry/syscalls/syscall_64.tbl2
-rw-r--r--arch/x86/kernel/shstk.c4
-rw-r--r--arch/x86/kernel/signal_64.c6
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;