diff options
| author | Philipp Rudo <prudo@linux.ibm.com> | 2020-04-06 14:47:48 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-05-10 10:30:09 +0200 |
| commit | bbe15f16e5c5cb24c855efd6102c1074740da514 (patch) | |
| tree | e6e6167a6045feaccc290a6fdd599bea2854ef19 | |
| parent | 6c662c519277d9d94f4d146b7c05e67a426b91a7 (diff) | |
| download | linux-stable-bbe15f16e5c5cb24c855efd6102c1074740da514.tar.gz linux-stable-bbe15f16e5c5cb24c855efd6102c1074740da514.tar.bz2 linux-stable-bbe15f16e5c5cb24c855efd6102c1074740da514.zip | |
s390/ftrace: fix potential crashes when switching tracers
[ Upstream commit 8ebf6da9db1b2a20bb86cc1bee2552e894d03308 ]
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 <prudo@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/s390/kernel/diag.c | 2 | ||||
| -rw-r--r-- | arch/s390/kernel/smp.c | 4 | ||||
| -rw-r--r-- | arch/s390/kernel/trace.c | 2 |
3 files changed, 4 insertions, 4 deletions
diff --git a/arch/s390/kernel/diag.c b/arch/s390/kernel/diag.c index 35c842aa8705..4c7cf8787a84 100644 --- a/arch/s390/kernel/diag.c +++ b/arch/s390/kernel/diag.c @@ -128,7 +128,7 @@ 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); diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index ecd24711f3aa..8e31dfd85de3 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -393,7 +393,7 @@ int smp_find_processor_id(u16 address) return -1; } -bool arch_vcpu_is_preempted(int cpu) +bool notrace arch_vcpu_is_preempted(int cpu) { if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu)) return false; @@ -403,7 +403,7 @@ bool arch_vcpu_is_preempted(int cpu) } EXPORT_SYMBOL(arch_vcpu_is_preempted); -void smp_yield_cpu(int cpu) +void notrace smp_yield_cpu(int cpu) { if (MACHINE_HAS_DIAG9C) { diag_stat_inc_norecursion(DIAG_STAT_X09C); diff --git a/arch/s390/kernel/trace.c b/arch/s390/kernel/trace.c index 490b52e85014..11a669f3cc93 100644 --- a/arch/s390/kernel/trace.c +++ b/arch/s390/kernel/trace.c @@ -14,7 +14,7 @@ EXPORT_TRACEPOINT_SYMBOL(s390_diagnose); static DEFINE_PER_CPU(unsigned int, diagnose_trace_depth); -void trace_s390_diagnose_norecursion(int diag_nr) +void notrace trace_s390_diagnose_norecursion(int diag_nr) { unsigned long flags; unsigned int *depth; |