diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index b4bb32082342..00ab5efa3833 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1244,6 +1244,8 @@ get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user, extern struct perf_callchain_entry *perf_callchain(struct perf_event *event, struct pt_regs *regs); extern int get_callchain_buffers(int max_stack); extern void put_callchain_buffers(void); +extern struct perf_callchain_entry *get_callchain_entry(int *rctx); +extern void put_callchain_entry(int rctx); extern int sysctl_perf_event_max_stack; extern int sysctl_perf_event_max_contexts_per_stack; diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c index 334d48b16c36..c6ce894e4ce9 100644 --- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -149,7 +149,7 @@ void put_callchain_buffers(void) } } -static struct perf_callchain_entry *get_callchain_entry(int *rctx) +struct perf_callchain_entry *get_callchain_entry(int *rctx) { int cpu; struct callchain_cpus_entries *entries; @@ -159,8 +159,10 @@ static struct perf_callchain_entry *get_callchain_entry(int *rctx) return NULL; entries = rcu_dereference(callchain_cpus_entries); - if (!entries) + if (!entries) { + put_recursion_context(this_cpu_ptr(callchain_recursion), *rctx); return NULL; + } cpu = smp_processor_id(); @@ -168,7 +170,7 @@ static struct perf_callchain_entry *get_callchain_entry(int *rctx) (*rctx * perf_callchain_entry__sizeof())); } -static void +void put_callchain_entry(int rctx) { put_recursion_context(this_cpu_ptr(callchain_recursion), rctx); @@ -183,11 +185,8 @@ get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user, int rctx; entry = get_callchain_entry(&rctx); - if (rctx == -1) - return NULL; - if (!entry) - goto exit_put; + return NULL; ctx.entry = entry; ctx.max_stack = max_stack;