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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 /arch/x86/kernel | |
| parent | 680ed2f15e70d079c8148589a3ce9426fc0ff914 (diff) | |
| download | linux-67840ad0fa14ad49a605074b12d5b0f3c3113ed1.tar.gz linux-67840ad0fa14ad49a605074b12d5b0f3c3113ed1.tar.bz2 linux-67840ad0fa14ad49a605074b12d5b0f3c3113ed1.zip | |
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 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/process_64.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/shstk.c | 8 |
2 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index e6db21c470aa..33b268747bb7 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -900,6 +900,7 @@ long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2) case ARCH_SHSTK_DISABLE: case ARCH_SHSTK_LOCK: case ARCH_SHSTK_UNLOCK: + case ARCH_SHSTK_STATUS: return shstk_prctl(task, option, arg2); default: ret = -EINVAL; diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c index d43b7a9c57ce..b26810c7cd1c 100644 --- a/arch/x86/kernel/shstk.c +++ b/arch/x86/kernel/shstk.c @@ -482,8 +482,14 @@ SYSCALL_DEFINE3(map_shadow_stack, unsigned long, addr, unsigned long, size, unsi return alloc_shstk(addr, aligned_size, size, set_tok); } -long shstk_prctl(struct task_struct *task, int option, unsigned long features) +long shstk_prctl(struct task_struct *task, int option, unsigned long arg2) { + unsigned long features = arg2; + + if (option == ARCH_SHSTK_STATUS) { + return put_user(task->thread.features, (unsigned long __user *)arg2); + } + if (option == ARCH_SHSTK_LOCK) { task->thread.features_locked |= features; return 0; |