From 8ebf6da9db1b2a20bb86cc1bee2552e894d03308 Mon Sep 17 00:00:00 2001 From: Philipp Rudo Date: Mon, 6 Apr 2020 14:47:48 +0200 Subject: s390/ftrace: fix potential crashes when switching tracers Switching tracers include instruction patching. To prevent that a instruction is patched while it's read the instruction patching is done in stop_machine 'context'. This also means that any function called during stop_machine must not be traced. Thus add 'notrace' to all functions called within stop_machine. Fixes: 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls") Fixes: 38f2c691a4b3 ("s390: improve wait logic of stop_machine") Fixes: 4ecf0a43e729 ("processor: get rid of cpu_relax_yield") Signed-off-by: Philipp Rudo Signed-off-by: Vasily Gorbik --- arch/s390/kernel/diag.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/s390/kernel/diag.c') diff --git a/arch/s390/kernel/diag.c b/arch/s390/kernel/diag.c index 61f2b0412345..ccba63aaeb47 100644 --- a/arch/s390/kernel/diag.c +++ b/arch/s390/kernel/diag.c @@ -133,7 +133,7 @@ void diag_stat_inc(enum diag_stat_enum nr) } EXPORT_SYMBOL(diag_stat_inc); -void diag_stat_inc_norecursion(enum diag_stat_enum nr) +void notrace diag_stat_inc_norecursion(enum diag_stat_enum nr) { this_cpu_inc(diag_stat.counter[nr]); trace_s390_diagnose_norecursion(diag_map[nr].code); -- cgit v1.2.3