diff options
| -rw-r--r-- | include/linux/perf_counter.h | 2 | ||||
| -rw-r--r-- | kernel/fork.c | 2 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 43 |
3 files changed, 43 insertions, 4 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 717bf3b59ba4..519a41bba249 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -579,6 +579,7 @@ extern void perf_counter_task_sched_out(struct task_struct *task, extern void perf_counter_task_tick(struct task_struct *task, int cpu); extern int perf_counter_init_task(struct task_struct *child); extern void perf_counter_exit_task(struct task_struct *child); +extern void perf_counter_free_task(struct task_struct *task); extern void perf_counter_do_pending(void); extern void perf_counter_print_debug(void); extern void __perf_disable(void); @@ -644,6 +645,7 @@ static inline void perf_counter_task_tick(struct task_struct *task, int cpu) { } static inline int perf_counter_init_task(struct task_struct *child) { return 0; } static inline void perf_counter_exit_task(struct task_struct *child) { } +static inline void perf_counter_free_task(struct task_struct *task) { } static inline void perf_counter_do_pending(void) { } static inline void perf_counter_print_debug(void) { } static inline void perf_disable(void) { } diff --git a/kernel/fork.c b/kernel/fork.c index c07c3335ceac..23bf757ed321 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1298,7 +1298,7 @@ bad_fork_cleanup_semundo: bad_fork_cleanup_audit: audit_free(p); bad_fork_cleanup_policy: - perf_counter_exit_task(p); + perf_counter_free_task(p); #ifdef CONFIG_NUMA mpol_put(p->mempolicy); bad_fork_cleanup_cgroup: diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 0c000d305e0e..79c3f26541d3 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -3538,8 +3538,7 @@ static void sync_child_counter(struct perf_counter *child_counter, } static void -__perf_counter_exit_task(struct task_struct *child, - struct perf_counter *child_counter, +__perf_counter_exit_task(struct perf_counter *child_counter, struct perf_counter_context *child_ctx) { struct perf_counter *parent_counter; @@ -3605,7 +3604,7 @@ void perf_counter_exit_task(struct task_struct *child) again: list_for_each_entry_safe(child_counter, tmp, &child_ctx->counter_list, list_entry) - __perf_counter_exit_task(child, child_counter, child_ctx); + __perf_counter_exit_task(child_counter, child_ctx); /* * If the last counter was a group counter, it will have appended all @@ -3621,6 +3620,44 @@ again: } /* + * free an unexposed, unused context as created by inheritance by + * init_task below, used by fork() in case of fail. + */ +void perf_counter_free_task(struct task_struct *task) +{ + struct perf_counter_context *ctx = task->perf_counter_ctxp; + struct perf_counter *counter, *tmp; + + if (!ctx) + return; + + mutex_lock(&ctx->mutex); +again: + list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry) { + struct perf_counter *parent = counter->parent; + + if (WARN_ON_ONCE(!parent)) + continue; + + mutex_lock(&parent->child_mutex); + list_del_init(&counter->child_list); + mutex_unlock(&parent->child_mutex); + + fput(parent->filp); + + list_del_counter(counter, ctx); + free_counter(counter); + } + + if (!list_empty(&ctx->counter_list)) + goto again; + + mutex_unlock(&ctx->mutex); + + put_ctx(ctx); +} + +/* * Initialize the perf_counter context in task_struct */ int perf_counter_init_task(struct task_struct *child) |