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| author | Rick Edgecombe <rick.p.edgecombe@intel.com> | 2023-06-12 17:11:08 -0700 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2023-08-02 15:01:51 -0700 |
| commit | 67840ad0fa14ad49a605074b12d5b0f3c3113ed1 (patch) | |
| tree | 7b134d61d3cadc36289a00923e71df1a23dd4ba2 /Documentation/arch | |
| parent | 680ed2f15e70d079c8148589a3ce9426fc0ff914 (diff) | |
| download | linux-67840ad0fa14ad49a605074b12d5b0f3c3113ed1.tar.gz | |
x86/shstk: Add ARCH_SHSTK_STATUS
CRIU and GDB need to get the current shadow stack and WRSS enablement
status. This information is already available via /proc/pid/status, but
this is inconvenient for CRIU because it involves parsing the text output
in an area of the code where this is difficult. Provide a status
arch_prctl(), ARCH_SHSTK_STATUS for retrieving the status. Have arg2 be a
userspace address, and make the new arch_prctl simply copy the features
out to userspace.
Suggested-by: Mike Rapoport <rppt@kernel.org>
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/20230613001108.3040476-43-rick.p.edgecombe%40intel.com
Diffstat (limited to 'Documentation/arch')
| -rw-r--r-- | Documentation/arch/x86/shstk.rst | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/arch/x86/shstk.rst b/Documentation/arch/x86/shstk.rst index f3553cc8c758ba..60260e809baf6a 100644 --- a/Documentation/arch/x86/shstk.rst +++ b/Documentation/arch/x86/shstk.rst @@ -79,6 +79,11 @@ arch_prctl(ARCH_SHSTK_UNLOCK, unsigned long features) Unlock features. 'features' is a mask of all features to unlock. All bits set are processed, unset bits are ignored. Only works via ptrace. +arch_prctl(ARCH_SHSTK_STATUS, unsigned long addr) + Copy the currently enabled features to the address passed in addr. The + features are described using the bits passed into the others in + 'features'. + The return values are as follows. On success, return 0. On error, errno can be:: @@ -86,6 +91,7 @@ be:: -ENOTSUPP if the feature is not supported by the hardware or kernel. -EINVAL arguments (non existing feature, etc) + -EFAULT if could not copy information back to userspace The feature's bits supported are:: |