diff options
| -rw-r--r-- | kernel/events/core.c | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index d78608323916..d7cf008f3d75 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -207,6 +207,19 @@ static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, __perf_ctx_unlock(&cpuctx->ctx); } +typedef struct { + struct perf_cpu_context *cpuctx; + struct perf_event_context *ctx; +} class_perf_ctx_lock_t; + +static inline void class_perf_ctx_lock_destructor(class_perf_ctx_lock_t *_T) +{ perf_ctx_unlock(_T->cpuctx, _T->ctx); } + +static inline class_perf_ctx_lock_t +class_perf_ctx_lock_constructor(struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx) +{ perf_ctx_lock(cpuctx, ctx); return (class_perf_ctx_lock_t){ cpuctx, ctx }; } + #define TASK_TOMBSTONE ((void *)-1L) static bool is_kernel_event(struct perf_event *event) @@ -944,7 +957,13 @@ static void perf_cgroup_switch(struct task_struct *task) if (READ_ONCE(cpuctx->cgrp) == cgrp) return; - perf_ctx_lock(cpuctx, cpuctx->task_ctx); + guard(perf_ctx_lock)(cpuctx, cpuctx->task_ctx); + /* + * Re-check, could've raced vs perf_remove_from_context(). + */ + if (READ_ONCE(cpuctx->cgrp) == NULL) + return; + perf_ctx_disable(&cpuctx->ctx, true); ctx_sched_out(&cpuctx->ctx, NULL, EVENT_ALL|EVENT_CGROUP); @@ -962,7 +981,6 @@ static void perf_cgroup_switch(struct task_struct *task) ctx_sched_in(&cpuctx->ctx, NULL, EVENT_ALL|EVENT_CGROUP); perf_ctx_enable(&cpuctx->ctx, true); - perf_ctx_unlock(cpuctx, cpuctx->task_ctx); } static int perf_cgroup_ensure_storage(struct perf_event *event, |