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| author | David S. Miller <davem@davemloft.net> | 2014-08-11 15:38:46 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-08-11 20:45:12 -0700 |
| commit | 8bccf5b313180faefce38e0d1140f76e0f327d28 (patch) | |
| tree | ed8d8f8c5696526f1ecf6fccd94680fe166427f4 | |
| parent | 58556104e9cd0107a7a8d2692cf04ef31669f6e4 (diff) | |
| download | op-kernel-dev-8bccf5b313180faefce38e0d1140f76e0f327d28.zip op-kernel-dev-8bccf5b313180faefce38e0d1140f76e0f327d28.tar.gz | |
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>
| -rw-r--r-- | arch/sparc/kernel/perf_event.c | 7 | ||||
| -rw-r--r-- | arch/sparc/kernel/process_64.c | 3 | ||||
| -rw-r--r-- | arch/sparc/kernel/smp_64.c | 1 |
3 files changed, 8 insertions, 3 deletions
diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c index 8efd337..d35c490 100644 --- a/arch/sparc/kernel/perf_event.c +++ b/arch/sparc/kernel/perf_event.c @@ -1671,9 +1671,12 @@ static bool __init supported_pmu(void) static int __init init_hw_perf_events(void) { + int err; + pr_info("Performance events: "); - if (!supported_pmu()) { + err = pcr_arch_init(); + if (err || !supported_pmu()) { pr_cont("No support for PMU type '%s'\n", sparc_pmu_type); return 0; } @@ -1685,7 +1688,7 @@ static int __init init_hw_perf_events(void) return 0; } -early_initcall(init_hw_perf_events); +pure_initcall(init_hw_perf_events); void perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs) diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c index 027e099..0be7bf9 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; diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c index 41aa247..f7ba875 100644 --- a/arch/sparc/kernel/smp_64.c +++ b/arch/sparc/kernel/smp_64.c @@ -1383,7 +1383,6 @@ void __cpu_die(unsigned int cpu) void __init smp_cpus_done(unsigned int max_cpus) { - pcr_arch_init(); } void smp_send_reschedule(int cpu) |
