s390/unwind: disable KMSAN checks

The unwind code can read uninitialized frames.  Furthermore, even in the
good case, KMSAN does not emit shadow for backchains.  Therefore disable
it for the unwinding functions.

Link: https://lkml.kernel.org/r/20240621113706.315500-37-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Ilya Leoshkevich 2024-06-21 13:35:20 +02:00 committed by Andrew Morton
parent e0bebfd63a
commit 7e17eac28a

View File

@ -49,6 +49,8 @@ static inline bool is_final_pt_regs(struct unwind_state *state,
READ_ONCE_NOCHECK(regs->psw.mask) & PSW_MASK_PSTATE;
}
/* Avoid KMSAN false positives from touching uninitialized frames. */
__no_kmsan_checks
bool unwind_next_frame(struct unwind_state *state)
{
struct stack_info *info = &state->stack_info;
@ -118,6 +120,8 @@ out_stop:
}
EXPORT_SYMBOL_GPL(unwind_next_frame);
/* Avoid KMSAN false positives from touching uninitialized frames. */
__no_kmsan_checks
void __unwind_start(struct unwind_state *state, struct task_struct *task,
struct pt_regs *regs, unsigned long first_frame)
{