diff options
| author | Rabin Vincent <rabin@rab.in> | 2014-11-06 22:26:07 +0100 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2014-11-10 22:47:31 +0100 |
| commit | 07906da78810dce5fd35b9449358c9208c693dca (patch) | |
| tree | 045b776e6ac22d844050cb6a155095732d9f40d4 /kernel/trace/trace.c | |
| parent | tracing: Do not busy wait in buffer splice (diff) | |
| download | linux-07906da78810dce5fd35b9449358c9208c693dca.tar.xz linux-07906da78810dce5fd35b9449358c9208c693dca.zip | |
tracing: Do not risk busy looping in buffer splice
If the read loop in trace_buffers_splice_read() keeps failing due to
memory allocation failures without reading even a single page then this
function will keep busy looping.
Remove the risk for that by exiting the function if memory allocation
failures are seen.
Link: http://lkml.kernel.org/r/1415309167-2373-2-git-send-email-rabin@rab.in
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 15209335888d..92f4a6cee172 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5494,7 +5494,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, }; struct buffer_ref *ref; int entries, size, i; - ssize_t ret; + ssize_t ret = 0; mutex_lock(&trace_types_lock); @@ -5532,13 +5532,16 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, int r; ref = kzalloc(sizeof(*ref), GFP_KERNEL); - if (!ref) + if (!ref) { + ret = -ENOMEM; break; + } ref->ref = 1; ref->buffer = iter->trace_buffer->buffer; ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file); if (!ref->page) { + ret = -ENOMEM; kfree(ref); break; } @@ -5576,6 +5579,9 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, /* did we read anything? */ if (!spd.nr_pages) { + if (ret) + goto out; + if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) { ret = -EAGAIN; goto out; |