From: "H.J. Lu" <hjl.tools@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: x86@kernel.org, Rick P Edgecombe <rick.p.edgecombe@intel.com>
Subject: [PATCH] x86/shstk: Enable shadow stack for x32
Date: Fri, 15 Mar 2024 07:04:33 -0700 [thread overview]
Message-ID: <20240315140433.1966543-1-hjl.tools@gmail.com> (raw)
1. Add shadow stack support to x32 signal.
2. Use the 64-bit map_shadow_stack syscall for x32.
3. Set up shadow stack for x32.
Tested with shadow stack enabled x32 glibc on Intel Tiger Lake.
Cc: Rick P Edgecombe <rick.p.edgecombe@intel.com>
Tested-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
---
arch/x86/entry/syscalls/syscall_64.tbl | 2 +-
arch/x86/kernel/shstk.c | 4 ++--
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;
--
2.44.0
next reply other threads:[~2024-03-15 14:04 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-15 14:04 H.J. Lu [this message]
2024-03-15 14:20 ` [PATCH] x86/shstk: Enable shadow stack for x32 Edgecombe, Rick P
2024-03-15 14:34 ` H.J. Lu
2024-03-22 14:07 ` Edgecombe, Rick P
2024-03-22 14:28 ` Edgecombe, Rick P
2024-03-22 15:06 ` H.J. Lu
2024-03-22 15:58 ` Edgecombe, Rick P
2024-03-22 16:07 ` H.J. Lu
2024-03-22 16:21 ` Edgecombe, Rick P
2024-03-22 16:35 ` H.J. Lu
2024-03-22 10:59 ` [tip: x86/shstk] x86/shstk: Enable shadow stacks " tip-bot2 for H.J. Lu
2024-03-22 16:49 ` Borislav Petkov
2024-03-22 16:49 ` [PATCH] x86/shstk: Enable shadow stack " Dave Hansen
2024-03-22 16:52 ` H.J. Lu
2024-03-22 16:56 ` Dave Hansen
2024-03-22 17:00 ` H.J. Lu
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