From 8bccf5b313180faefce38e0d1140f76e0f327d28 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Mon, 11 Aug 2014 15:38:46 -0700 Subject: 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 Signed-off-by: David S. Miller --- arch/sparc/kernel/process_64.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/sparc/kernel/process_64.c') 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; -- cgit v1.2.3