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| author |   Philipp Rudo <prudo@linux.ibm.com> | 2020-04-06 14:47:48 +0200 |
|---|---|---|
| committer |   Vasily Gorbik <gor@linux.ibm.com> | 2020-04-22 16:20:55 +0200 |
| commit | 8ebf6da9db1b2a20bb86cc1bee2552e894d03308 (patch) | |
| tree | 5f29c829690f812c8690f40ebedcf53fb60aae27 /arch/s390/kernel/smp.c | |
| parent | Linux 5.7-rc2 (diff) | |
| download | linux-dev-8ebf6da9db1b2a20bb86cc1bee2552e894d03308.tar.xz linux-dev-8ebf6da9db1b2a20bb86cc1bee2552e894d03308.zip | |
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 <prudo@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/smp.c')
| -rw-r--r-- | arch/s390/kernel/smp.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 7eaabbab2213..10dbb12eb14d 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -403,7 +403,7 @@ 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; @@ -413,7 +413,7 @@ 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) return; |