diff options
| author | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-09-27 19:15:27 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-10-26 12:34:31 +0200 |
| commit | 2475de2bc0de17fb1b24c5e90194f84b5ca70d3e (patch) | |
| tree | d65edd5386f3c0dd3e7ec61df64ab8ffc477851c /kernel | |
| parent | 48272aa48d80a1ed877bc4398594def6c8e7920f (diff) | |
tracing: Wake up ring buffer waiters on closing of the file
commit f3ddb74ad0790030c9592229fb14d8c451f4e9a8 upstream.
When the file that represents the ring buffer is closed, there may be
waiters waiting on more input from the ring buffer. Call
ring_buffer_wake_waiters() to wake up any waiters when the file is
closed.
Link: https://lkml.kernel.org/r/20220927231825.182416969@goodmis.org
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: e30f53aad2202 ("tracing: Do not busy wait in buffer splice")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 61090aec498e..bf0b693143d0 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8117,6 +8117,12 @@ static int tracing_buffers_release(struct inode *inode, struct file *file) __trace_array_put(iter->tr); + iter->wait_index++; + /* Make sure the waiters see the new wait_index */ + smp_wmb(); + + ring_buffer_wake_waiters(iter->array_buffer->buffer, iter->cpu_file); + if (info->spare) ring_buffer_free_read_page(iter->array_buffer->buffer, info->spare_cpu, info->spare); @@ -8270,6 +8276,8 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, /* did we read anything? */ if (!spd.nr_pages) { + long wait_index; + if (ret) goto out; @@ -8277,10 +8285,17 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) goto out; + wait_index = READ_ONCE(iter->wait_index); + ret = wait_on_pipe(iter, iter->tr->buffer_percent); if (ret) goto out; + /* Make sure we see the new wait_index */ + smp_rmb(); + if (wait_index != iter->wait_index) + goto out; + goto again; } |