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	perf/bpf: Convert perf_event_array to use struct file
Robustify refcounting. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Wang Nan <wangnan0@huawei.com> Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160126045947.GA40151@ast-mbp.thefacebook.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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					 4 changed files with 33 additions and 27 deletions
				
			
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			@ -729,7 +729,7 @@ extern int perf_event_init_task(struct task_struct *child);
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extern void perf_event_exit_task(struct task_struct *child);
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extern void perf_event_free_task(struct task_struct *task);
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extern void perf_event_delayed_put(struct task_struct *task);
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extern struct perf_event *perf_event_get(unsigned int fd);
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extern struct file *perf_event_get(unsigned int fd);
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extern const struct perf_event_attr *perf_event_attrs(struct perf_event *event);
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extern void perf_event_print_debug(void);
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extern void perf_pmu_disable(struct pmu *pmu);
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			@ -1070,7 +1070,7 @@ static inline int perf_event_init_task(struct task_struct *child)	{ return 0; }
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static inline void perf_event_exit_task(struct task_struct *child)	{ }
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static inline void perf_event_free_task(struct task_struct *task)	{ }
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static inline void perf_event_delayed_put(struct task_struct *task)	{ }
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static inline struct perf_event *perf_event_get(unsigned int fd)	{ return ERR_PTR(-EINVAL); }
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static inline struct file *perf_event_get(unsigned int fd)	{ return ERR_PTR(-EINVAL); }
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static inline const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
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{
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	return ERR_PTR(-EINVAL);
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			@ -291,10 +291,13 @@ static void *perf_event_fd_array_get_ptr(struct bpf_map *map, int fd)
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{
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	struct perf_event *event;
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	const struct perf_event_attr *attr;
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	struct file *file;
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	event = perf_event_get(fd);
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	if (IS_ERR(event))
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		return event;
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	file = perf_event_get(fd);
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	if (IS_ERR(file))
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		return file;
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	event = file->private_data;
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	attr = perf_event_attrs(event);
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	if (IS_ERR(attr))
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			@ -304,24 +307,22 @@ static void *perf_event_fd_array_get_ptr(struct bpf_map *map, int fd)
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		goto err;
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	if (attr->type == PERF_TYPE_RAW)
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		return event;
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		return file;
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	if (attr->type == PERF_TYPE_HARDWARE)
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		return event;
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		return file;
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	if (attr->type == PERF_TYPE_SOFTWARE &&
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	    attr->config == PERF_COUNT_SW_BPF_OUTPUT)
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		return event;
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		return file;
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err:
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	perf_event_release_kernel(event);
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	fput(file);
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	return ERR_PTR(-EINVAL);
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}
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static void perf_event_fd_array_put_ptr(void *ptr)
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{
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	struct perf_event *event = ptr;
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	perf_event_release_kernel(event);
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	fput((struct file *)ptr);
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}
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static const struct bpf_map_ops perf_event_array_ops = {
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			@ -8916,21 +8916,20 @@ void perf_event_delayed_put(struct task_struct *task)
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		WARN_ON_ONCE(task->perf_event_ctxp[ctxn]);
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}
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struct perf_event *perf_event_get(unsigned int fd)
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struct file *perf_event_get(unsigned int fd)
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{
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	int err;
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	struct fd f;
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	struct perf_event *event;
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	struct file *file;
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	err = perf_fget_light(fd, &f);
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	if (err)
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		return ERR_PTR(err);
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	file = fget_raw(fd);
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	if (!file)
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		return ERR_PTR(-EBADF);
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	event = f.file->private_data;
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	atomic_long_inc(&event->refcount);
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	fdput(f);
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	if (file->f_op != &perf_fops) {
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		fput(file);
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		return ERR_PTR(-EBADF);
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	}
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	return event;
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	return file;
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}
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const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
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			@ -191,14 +191,17 @@ static u64 bpf_perf_event_read(u64 r1, u64 index, u64 r3, u64 r4, u64 r5)
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	struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
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	struct bpf_array *array = container_of(map, struct bpf_array, map);
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	struct perf_event *event;
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	struct file *file;
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	if (unlikely(index >= array->map.max_entries))
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		return -E2BIG;
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	event = (struct perf_event *)array->ptrs[index];
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	if (!event)
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	file = (struct file *)array->ptrs[index];
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	if (unlikely(!file))
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		return -ENOENT;
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	event = file->private_data;
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	/* make sure event is local and doesn't have pmu::count */
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	if (event->oncpu != smp_processor_id() ||
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	    event->pmu->count)
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			@ -228,6 +231,7 @@ static u64 bpf_perf_event_output(u64 r1, u64 r2, u64 index, u64 r4, u64 size)
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	void *data = (void *) (long) r4;
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	struct perf_sample_data sample_data;
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	struct perf_event *event;
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	struct file *file;
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	struct perf_raw_record raw = {
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		.size = size,
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		.data = data,
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			@ -236,10 +240,12 @@ static u64 bpf_perf_event_output(u64 r1, u64 r2, u64 index, u64 r4, u64 size)
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	if (unlikely(index >= array->map.max_entries))
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		return -E2BIG;
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	event = (struct perf_event *)array->ptrs[index];
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	if (unlikely(!event))
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	file = (struct file *)array->ptrs[index];
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	if (unlikely(!file))
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		return -ENOENT;
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	event = file->private_data;
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	if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
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		     event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
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		return -EINVAL;
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