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| author | Rick Edgecombe <rick.p.edgecombe@intel.com> | 2023-06-12 17:10:54 -0700 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2023-08-02 15:01:50 -0700 |
| commit | 2d39a6add422ac78254927ec2194838c33ae4fb2 (patch) | |
| tree | 466fd0ea8271b73a82b2c6d37770321131b9d4cd /arch/x86/include/asm/processor.h | |
| parent | a5f6c2ace9974adf92ce65dacca8126d90adabfe (diff) | |
| download | lwn-2d39a6add422ac78254927ec2194838c33ae4fb2.tar.gz lwn-2d39a6add422ac78254927ec2194838c33ae4fb2.zip | |
x86/shstk: Add user-mode shadow stack support
Introduce basic shadow stack enabling/disabling/allocation routines.
A task's shadow stack is allocated from memory with VM_SHADOW_STACK flag
and has a fixed size of min(RLIMIT_STACK, 4GB).
Keep the task's shadow stack address and size in thread_struct. This will
be copied when cloning new threads, but needs to be cleared during exec,
so add a function to do this.
32 bit shadow stack is not expected to have many users and it will
complicate the signal implementation. So do not support IA32 emulation
or x32.
Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-29-rick.p.edgecombe%40intel.com
Diffstat (limited to 'arch/x86/include/asm/processor.h')
| -rw-r--r-- | arch/x86/include/asm/processor.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 4e35f40ea1e6..b216ac80ebcc 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -479,6 +479,8 @@ struct thread_struct { #ifdef CONFIG_X86_USER_SHADOW_STACK unsigned long features; unsigned long features_locked; + + struct thread_shstk shstk; #endif /* Floating point and extended processor state */ |