diff options
| -rw-r--r-- | Documentation/arch/x86/shstk.rst | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/shstk.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/uapi/asm/prctl.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/process_64.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/shstk.c | 8 |
5 files changed, 16 insertions, 2 deletions
diff --git a/Documentation/arch/x86/shstk.rst b/Documentation/arch/x86/shstk.rst index f3553cc8c758..60260e809baf 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:: diff --git a/arch/x86/include/asm/shstk.h b/arch/x86/include/asm/shstk.h index ecb23a8ca47d..42fee8959df7 100644 --- a/arch/x86/include/asm/shstk.h +++ b/arch/x86/include/asm/shstk.h @@ -14,7 +14,7 @@ struct thread_shstk { u64 size; }; -long shstk_prctl(struct task_struct *task, int option, unsigned long features); +long shstk_prctl(struct task_struct *task, int option, unsigned long arg2); void reset_thread_features(void); unsigned long shstk_alloc_thread_stack(struct task_struct *p, unsigned long clone_flags, unsigned long stack_size); diff --git a/arch/x86/include/uapi/asm/prctl.h b/arch/x86/include/uapi/asm/prctl.h index 3189c4a96468..384e2cc6ac19 100644 --- a/arch/x86/include/uapi/asm/prctl.h +++ b/arch/x86/include/uapi/asm/prctl.h @@ -34,6 +34,7 @@ #define ARCH_SHSTK_DISABLE 0x5002 #define ARCH_SHSTK_LOCK 0x5003 #define ARCH_SHSTK_UNLOCK 0x5004 +#define ARCH_SHSTK_STATUS 0x5005 /* ARCH_SHSTK_ features bits */ #define ARCH_SHSTK_SHSTK (1ULL << 0) 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; |