diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2025-10-27 09:43:48 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-11-03 15:26:09 +0100 |
| commit | 5002dd53144f82d43eba778c927adfa7d429c16a (patch) | |
| tree | 900c0f4d43f8186518576ef44ca70896ce0486a6 | |
| parent | 14219398e3e1ce774d47b2dd55852d9b693cc6e1 (diff) | |
powerpc/uaccess: Use unsafe wrappers for ASM GOTO
ASM GOTO is miscompiled by GCC when it is used inside a auto cleanup scope:
bool foo(u32 __user *p, u32 val)
{
scoped_guard(pagefault)
unsafe_put_user(val, p, efault);
return true;
efault:
return false;
}
It ends up leaking the pagefault disable counter in the fault path. clang
at least fails the build.
Rename unsafe_*_user() to arch_unsafe_*_user() which makes the generic
uaccess header wrap it with a local label that makes both compilers emit
correct code. Same for the kernel_nofault() variants.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251027083745.356628509@linutronix.de
| -rw-r--r-- | arch/powerpc/include/asm/uaccess.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index 4f5a46a77fa2..784a00e681fa 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -451,7 +451,7 @@ user_write_access_begin(const void __user *ptr, size_t len) #define user_write_access_begin user_write_access_begin #define user_write_access_end prevent_current_write_to_user -#define unsafe_get_user(x, p, e) do { \ +#define arch_unsafe_get_user(x, p, e) do { \ __long_type(*(p)) __gu_val; \ __typeof__(*(p)) __user *__gu_addr = (p); \ \ @@ -459,7 +459,7 @@ user_write_access_begin(const void __user *ptr, size_t len) (x) = (__typeof__(*(p)))__gu_val; \ } while (0) -#define unsafe_put_user(x, p, e) \ +#define arch_unsafe_put_user(x, p, e) \ __put_user_size_goto((__typeof__(*(p)))(x), (p), sizeof(*(p)), e) #define unsafe_copy_from_user(d, s, l, e) \ @@ -504,11 +504,11 @@ do { \ unsafe_put_user(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e); \ } while (0) -#define __get_kernel_nofault(dst, src, type, err_label) \ +#define arch_get_kernel_nofault(dst, src, type, err_label) \ __get_user_size_goto(*((type *)(dst)), \ (__force type __user *)(src), sizeof(type), err_label) -#define __put_kernel_nofault(dst, src, type, err_label) \ +#define arch_put_kernel_nofault(dst, src, type, err_label) \ __put_user_size_goto(*((type *)(src)), \ (__force type __user *)(dst), sizeof(type), err_label) |