From: Namhyung Kim <[email protected]> The ring_buffer_read_prepare() can return NULL if memory allocation fails. Fail out in this case instead of succedding and then having no output.
Suggested-by: Steven Rostedt <[email protected]> Signed-off-by: Namhyung Kim <[email protected]> --- kernel/trace/trace.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7270460cfe3c..13200de31f0b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2826,6 +2826,8 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot) for_each_tracing_cpu(cpu) { iter->buffer_iter[cpu] = ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); + if (!iter->buffer_iter[cpu]) + goto free; } ring_buffer_read_prepare_sync(); for_each_tracing_cpu(cpu) { @@ -2836,6 +2838,9 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot) cpu = iter->cpu_file; iter->buffer_iter[cpu] = ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); + if (!iter->buffer_iter[cpu]) + goto free; + ring_buffer_read_prepare_sync(); ring_buffer_read_start(iter->buffer_iter[cpu]); tracing_iter_reset(iter, cpu); @@ -2847,6 +2852,23 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot) return iter; +free: + /* + * For simplicity, just keep single loop without comparing cpu_file. + */ + for_each_tracing_cpu(cpu) { + if (iter->buffer_iter[cpu]) + ring_buffer_read_finish(iter->buffer_iter[cpu]); + } + + if (iter->trace && iter->trace->close) + iter->trace->close(iter); + + if (!iter->snapshot) + tracing_start_tr(tr); + + mutex_destroy(&iter->mutex); + free_cpumask_var(iter->started); fail: mutex_unlock(&trace_types_lock); kfree(iter->trace); -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
