[libvirt] [PATCH 01/11] Block SIGPIPE around virExec hook functions

Some functionality run in virExec hooks may do I/O which can trigger SIGPIPE. Renable SIGPIPE blocking around the hook function * src/util/util.c: Block SIGPIPE around hooks --- src/util/util.c | 24 +++++++++++++++++++++++- 1 files changed, 23 insertions(+), 1 deletions(-) diff --git a/src/util/util.c b/src/util/util.c index f412a83..78ac168 100644 --- a/src/util/util.c +++ b/src/util/util.c @@ -642,12 +642,34 @@ __virExec(const char *const*argv, } } - if (hook) + if (hook) { + /* virFork reset all signal handlers to the defaults. + * This is good for the child process, but our hook + * risks running something that generates SIGPIPE, + * so we need to temporarily block that again + */ + struct sigaction waxon, waxoff; + waxoff.sa_handler = SIG_IGN; + waxoff.sa_flags = 0; + memset(&waxon, 0, sizeof(waxon)); + if (sigaction(SIGPIPE, &waxoff, &waxon) < 0) { + virReportSystemError(errno, "%s", + _("Could not disable SIGPIPE")); + goto fork_error; + } + if ((hook)(data) != 0) { VIR_DEBUG0("Hook function failed."); goto fork_error; } + if (sigaction(SIGPIPE, &waxon, NULL) < 0) { + virReportSystemError(errno, "%s", + _("Could not re-enable SIGPIPE")); + goto fork_error; + } + } + /* The steps above may need todo something privileged, so * we delay clearing capabilities until the last minute */ if ((flags & VIR_EXEC_CLEAR_CAPS) && -- 1.7.3.4