On 03.01.2012 20:00, Eric Blake wrote:
On 01/03/2012 10:58 AM, Michal Privoznik wrote:
It is a good practise to set revents to zero before doing any poll(). Moreover, we should check if event we waited for really occurred or if any of fds we were polling on didn't encountered hangup.
Looks like this also solves:
https://bugzilla.redhat.com/show_bug.cgi?id=770788
--- src/util/command.c | 21 +++++++++++++++++---- 1 files changed, 17 insertions(+), 4 deletions(-)
Should we also be probing for POLLERR? (POLLNVAL shouldn't ever be present, because it would indicate a bigger bug in our code).
ACK - what you have is a strict improvement, even if we further decide to check for POLLERR.
Thanks, pushed with this squashed in: diff --git a/src/util/command.c b/src/util/command.c index 9b553f0..bdaa88b 100644 --- a/src/util/command.c +++ b/src/util/command.c @@ -1687,7 +1687,10 @@ virCommandProcessIO(virCommandPtr cmd) memcpy(*buf + *len, data, done); *len += done; } - } else if (fds[i].revents & POLLOUT) { + } + + if (fds[i].revents & POLLOUT && + fds[i].fd == infd) { int done; /* Coverity 5.3.0 can't see that we only get here if @@ -1711,7 +1714,9 @@ virCommandProcessIO(virCommandPtr cmd) VIR_DEBUG("ignoring failed close on fd %d", tmpfd); } } - } else if (fds[i].revents & POLLHUP) { + } + + if (fds[i].revents & (POLLHUP | POLLERR)) { if (fds[i].fd == errfd) { VIR_DEBUG("hangup on stderr"); errfd = -1;