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author | David S. Miller <davem@davemloft.net> | 2014-08-11 15:38:46 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2014-08-11 20:45:12 -0700 |
commit | 8bccf5b313180faefce38e0d1140f76e0f327d28 (patch) | |
tree | ed8d8f8c5696526f1ecf6fccd94680fe166427f4 /arch/sparc/kernel/process_64.c | |
parent | 58556104e9cd0107a7a8d2692cf04ef31669f6e4 (diff) | |
download | linux-stable-8bccf5b313180faefce38e0d1140f76e0f327d28.tar.gz linux-stable-8bccf5b313180faefce38e0d1140f76e0f327d28.tar.bz2 linux-stable-8bccf5b313180faefce38e0d1140f76e0f327d28.zip |
sparc64: Fix pcr_ops initialization and usage bugs.
Christopher reports that perf_event_print_debug() can crash in uniprocessor
builds. The crash is due to pcr_ops being NULL.
This happens because pcr_arch_init() is only invoked by smp_cpus_done() which
only executes in SMP builds.
init_hw_perf_events() is closely intertwined with pcr_ops being setup properly,
therefore:
1) Call pcr_arch_init() early on from init_hw_perf_events(), instead of
from smp_cpus_done().
2) Do not hook up a PMU type if pcr_ops is NULL after pcr_arch_init().
3) Move init_hw_perf_events to a later initcall so that it we will be
sure to invoke pcr_arch_init() after all cpus are brought up.
Finally, guard the one naked sequence of pcr_ops dereferences in
__global_pmu_self() with an appropriate NULL check.
Reported-by: Christopher Alexander Tobias Schulze <cat.schulze@alice-dsl.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/kernel/process_64.c')
-rw-r--r-- | arch/sparc/kernel/process_64.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c index 027e09986194..0be7bf978cb1 100644 --- a/arch/sparc/kernel/process_64.c +++ b/arch/sparc/kernel/process_64.c @@ -312,6 +312,9 @@ static void __global_pmu_self(int this_cpu) struct global_pmu_snapshot *pp; int i, num; + if (!pcr_ops) + return; + pp = &global_cpu_snapshot[this_cpu].pmu; num = 1; |