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.
S390 is not affected for unsafe_*_user() as it uses it's own local label
already, but __get/put_kernel_nofault() lack that.
Rename them to arch_*_kernel_nofault() which makes the generic uaccess
header wrap it with a local label that makes both compilers emit correct
code.
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: [email protected]
---
arch/s390/include/asm/uaccess.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -468,8 +468,8 @@ do {
\
#endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT && CONFIG_CC_HAS_ASM_AOR_FORMAT_FLAGS
*/
-#define __get_kernel_nofault __mvc_kernel_nofault
-#define __put_kernel_nofault __mvc_kernel_nofault
+#define arch_get_kernel_nofault __mvc_kernel_nofault
+#define arch_put_kernel_nofault __mvc_kernel_nofault
void __cmpxchg_user_key_called_with_bad_pointer(void);
