Re: [PATCH v2 04/10] s390/runtime-const: Serialize text patching with text_mutex

[Ilya Leoshkevich <iii@linux.ibm.com>]

On 10/27/26 15:30, Heiko Carstens wrote:
> Acquire text_mutex inside runtime_const_fixup() around the patching
> loop.
> 
> Serialization is not required for runtime_const_fixup(), however this is
> part of larger series where at the end s390_kernel_write() requires that
> callers hold text_mutex.
> 
> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
> ---
>   arch/s390/include/asm/runtime-const.h | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/arch/s390/include/asm/runtime-const.h b/arch/s390/include/asm/runtime-const.h
> index 7b71156031ec..0e2402717e8b 100644
> --- a/arch/s390/include/asm/runtime-const.h
> +++ b/arch/s390/include/asm/runtime-const.h
> @@ -3,6 +3,7 @@
>   #define _ASM_S390_RUNTIME_CONST_H
>   
>   #include <linux/uaccess.h>
> +#include <linux/memory.h>
>   
>   #define runtime_const_ptr(sym)					\
>   ({								\
> @@ -88,6 +89,7 @@ static inline void __runtime_fixup_mask(void *where, unsigned long val)
>   static inline void runtime_const_fixup(void (*fn)(void *, unsigned long),
>   				       unsigned long val, s32 *start, s32 *end)
>   {
> +	guard(mutex)(&text_mutex);
>   	while (start < end) {
>   		fn(*start + (void *)start, val);
>   		start++;

Interesting, so clang is able to propagate context even through indirect
calls without explicit annotations?


Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>