s390/unwind: cleanup unused READ_ONCE_TASK_STACK

Kasan instrumentation of backchain unwinder stack reads is disabled
completely and simply uses READ_ONCE_NOCHECK now.
READ_ONCE_TASK_STACK macro is unused and could be removed.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Vasily Gorbik 2019-06-20 10:18:35 +02:00
parent 2095574632
commit da17767336

View File

@ -79,23 +79,4 @@ static inline void unwind_module_init(struct module *mod, void *orc_ip,
size_t orc_ip_size, void *orc,
size_t orc_size) {}
#ifdef CONFIG_KASAN
/*
* This disables KASAN checking when reading a value from another task's stack,
* since the other task could be running on another CPU and could have poisoned
* the stack in the meantime.
*/
#define READ_ONCE_TASK_STACK(task, x) \
({ \
unsigned long val; \
if (task == current) \
val = READ_ONCE(x); \
else \
val = READ_ONCE_NOCHECK(x); \
val; \
})
#else
#define READ_ONCE_TASK_STACK(task, x) READ_ONCE(x)
#endif
#endif /* _ASM_S390_UNWIND_H */