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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>
hifive-unleashed-5.1
Alexei Starovoitov 2016-01-25 20:59:49 -08:00 committed by Ingo Molnar
parent 828b6f0e26
commit e03e7ee34f
4 changed files with 33 additions and 27 deletions
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4
include/linux/perf_event.h
View File

@ -729,7 +729,7 @@ extern int perf_event_init_task(struct task_struct *child);
extern void perf_event_exit_task(struct task_struct *child);
extern void perf_event_free_task(struct task_struct *task);
extern void perf_event_delayed_put(struct task_struct *task);
extern struct perf_event *perf_event_get(unsigned int fd);
extern struct file *perf_event_get(unsigned int fd);
extern const struct perf_event_attr *perf_event_attrs(struct perf_event *event);
extern void perf_event_print_debug(void);
extern void perf_pmu_disable(struct pmu *pmu);
@ -1070,7 +1070,7 @@ static inline int perf_event_init_task(struct task_struct *child) { return 0; }
static inline void perf_event_exit_task(struct task_struct *child) { }
static inline void perf_event_free_task(struct task_struct *task) { }
static inline void perf_event_delayed_put(struct task_struct *task) { }
static inline struct perf_event *perf_event_get(unsigned int fd) { return ERR_PTR(-EINVAL); }
static inline struct file *perf_event_get(unsigned int fd) { return ERR_PTR(-EINVAL); }
static inline const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
{
return ERR_PTR(-EINVAL);

21
kernel/bpf/arraymap.c
View File

@ -291,10 +291,13 @@ static void *perf_event_fd_array_get_ptr(struct bpf_map *map, int fd)
{
struct perf_event *event;
const struct perf_event_attr *attr;
struct file *file;
event = perf_event_get(fd);
if (IS_ERR(event))
return event;
file = perf_event_get(fd);
if (IS_ERR(file))
return file;
event = file->private_data;
attr = perf_event_attrs(event);
if (IS_ERR(attr))
@ -304,24 +307,22 @@ static void *perf_event_fd_array_get_ptr(struct bpf_map *map, int fd)
goto err;
if (attr->type == PERF_TYPE_RAW)
return event;
return file;
if (attr->type == PERF_TYPE_HARDWARE)
return event;
return file;
if (attr->type == PERF_TYPE_SOFTWARE &&
attr->config == PERF_COUNT_SW_BPF_OUTPUT)
return event;
return file;
err:
perf_event_release_kernel(event);
fput(file);
return ERR_PTR(-EINVAL);
}
static void perf_event_fd_array_put_ptr(void *ptr)
{
struct perf_event *event = ptr;
perf_event_release_kernel(event);
fput((struct file *)ptr);
}
static const struct bpf_map_ops perf_event_array_ops = {

21
kernel/events/core.c
View File

@ -8916,21 +8916,20 @@ void perf_event_delayed_put(struct task_struct *task)
WARN_ON_ONCE(task->perf_event_ctxp[ctxn]);
}
struct perf_event *perf_event_get(unsigned int fd)
struct file *perf_event_get(unsigned int fd)
{
int err;
struct fd f;
struct perf_event *event;
struct file *file;
err = perf_fget_light(fd, &f);
if (err)
return ERR_PTR(err);
file = fget_raw(fd);
if (!file)
return ERR_PTR(-EBADF);
event = f.file->private_data;
atomic_long_inc(&event->refcount);
fdput(f);
if (file->f_op != &perf_fops) {
fput(file);
return ERR_PTR(-EBADF);
}
return event;
return file;
}
const struct perf_event_attr *perf_event_attrs(struct perf_event *event)

14
kernel/trace/bpf_trace.c
View File

@ -191,14 +191,17 @@ static u64 bpf_perf_event_read(u64 r1, u64 index, u64 r3, u64 r4, u64 r5)
struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
struct bpf_array *array = container_of(map, struct bpf_array, map);
struct perf_event *event;
struct file *file;
if (unlikely(index >= array->map.max_entries))
return -E2BIG;
event = (struct perf_event *)array->ptrs[index];
if (!event)
file = (struct file *)array->ptrs[index];
if (unlikely(!file))
return -ENOENT;
event = file->private_data;
/* make sure event is local and doesn't have pmu::count */
if (event->oncpu != smp_processor_id() ||
event->pmu->count)
@ -228,6 +231,7 @@ static u64 bpf_perf_event_output(u64 r1, u64 r2, u64 index, u64 r4, u64 size)
void *data = (void *) (long) r4;
struct perf_sample_data sample_data;
struct perf_event *event;
struct file *file;
struct perf_raw_record raw = {
.size = size,
.data = data,
@ -236,10 +240,12 @@ static u64 bpf_perf_event_output(u64 r1, u64 r2, u64 index, u64 r4, u64 size)
if (unlikely(index >= array->map.max_entries))
return -E2BIG;
event = (struct perf_event *)array->ptrs[index];
if (unlikely(!event))
file = (struct file *)array->ptrs[index];
if (unlikely(!file))
return -ENOENT;
event = file->private_data;
if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
return -EINVAL;