To allow coredump pipe readers to look at /proc/<pid> of the crashing process, the kernel waits for the reader to exit. However, the wait is silently aborted if the crashing process is signalled. This patch, logs whenever wait_for_dump_helpers is aborted or in order to assist in debugging cases where /proc/<pid> is gone. Alternatively, we may want to consider not aborting on a signal. You could always break the loop by killing the reader process. Reference: http://crosbug.com/21559 Signed-off-by: Mandeep Singh Baines <msb@xxxxxxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Neil Horman <nhorman@xxxxxxxxxxxxx> Cc: Earl Chew <earl_chew@xxxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Andi Kleen <andi@xxxxxxxxxxxxxx> Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: linux-fsdevel@xxxxxxxxxxxxxxx --- fs/exec.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 25dcbe5..5d4190d 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -2030,7 +2030,14 @@ static void wait_for_dump_helpers(struct file *file) pipe->readers++; pipe->writers--; - while ((pipe->readers > 1) && (!signal_pending(current))) { + while (pipe->readers > 1) { + if (signal_pending(current)) { + pr_info("wait_for_dump_helpers[%d]: " + "aborted due to signal\n", + task_pid_nr(current)); + break; + } + wake_up_interruptible_sync(&pipe->wait); kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); pipe_wait(pipe); -- 1.7.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
