Re: [libvirt] [PATCH] command: properly diagnose process exit via signal

Child processes don't always reach _exit(); if they die from a signal, then any messages should still be accurate. Most users either expect a 0 status (thankfully, if status==0, then WIFEXITED(status) is true and WEXITSTATUS(status)==0 for all known platforms) or were filtering on WIFEXITED before printing a status, but a few were missing this check. Additionally, nwfilter_ebiptables_driver was making an assumption that works on Linux (where WEXITSTATUS shifts and WTERMSIG just masks) but fails on other platforms (where WEXITSTATUS just masks and WTERMSIG shifts). * src/util/command.h (virCommandTranslateStatus): New helper. * src/libvirt_private.syms (command.h): Export it. * src/util/command.c (virCommandTranslateStatus): New function. (virCommandWait): Use it to also diagnose status from signals. * src/security/security_apparmor.c (load_profile): Likewise. * src/storage/storage_backend.c (virStorageBackendQEMUImgBackingFormat): Likewise. * src/util/util.c (virExecDaemonize, virRunWithHook) (virFileOperation, virDirCreate): Likewise. * daemon/remote.c (remoteDispatchAuthPolkit): Likewise. * src/nwfilter/nwfilter_ebiptables_driver.c (ebiptablesExecCLI): Likewise. --- In response to my finding here: https://www.redhat.com/archives/libvir-list/2011-March/msg01029.html > status includes normal exit and signals. This should probably use > WIFEXITED and WEXITSTATUS to avoid printing values shifted by 8. For > that matter, I just noticed that virCommandWait should probably be more > careful in how it interprets status. daemon/remote.c | 11 +++++++- src/libvirt_private.syms | 1 + src/nwfilter/nwfilter_ebiptables_driver.c | 16 ++++++++++--- src/security/security_apparmor.c | 22 ++++++++++++------ src/storage/storage_backend.c | 18 ++++++--------- src/util/command.c | 34 ++++++++++++++++++++++++++-- src/util/command.h | 7 +++++- src/util/util.c | 27 ++++++++++------------ 8 files changed, 92 insertions(+), 44 deletions(-)

if (status != 0) { - VIR_ERROR(_("Policy kit denied action %s from pid %d, uid %d, result: %d"), - action, callerPid, callerUid, status); + char *tmp = virCommandTranslateStatus(status); + if (!tmp) { + virReportOOMError(); + goto authfail; + } + VIR_ERROR(_("Policy kit denied action %s from pid %d, uid %d: %s"), + action, callerPid, callerUid, tmp); + VIR_FREE(tmp); goto authdeny;