[libvirt] [PATCH] fix errors in virReportSystemErrorFull

While looking at removing most of the remaining uses of strerror, I spotted problems in virReportSystemErrorFull. 1) it would leak "combined" 2) that allocated, written-into buffer wasn't even used So, since we'd rather avoid having to allocate at all in the error-reporting path (esp for OOM errors), I've made it automatic. From: Jim Meyering <meyering(a)redhat.com&gt; Date: Mon, 26 Jan 2009 14:59:35 +0100 Subject: [PATCH] fix errors in virReportSystemErrorFull * src/virterror.c (virReportSystemErrorFull): Don't leak "combined". In fact, don't even attempt allocation. Do include the result of formatted print in final diagnostic. --- src/virterror.c | 13 +++++++++---- 1 files changed, 9 insertions(+), 4 deletions(-) diff --git a/src/virterror.c b/src/virterror.c index 0c66781..cfde1dc 100644 --- a/src/virterror.c +++ b/src/virterror.c @@ -1019,7 +1019,7 @@ void virReportSystemErrorFull(virConnectPtr conn, char systemError[1024]; char *theerrnostr; const char *virerr; - char *combined = NULL; + char combined[2048]; #ifdef HAVE_STRERROR_R #ifdef __USE_GNU @@ -1047,10 +1047,15 @@ void virReportSystemErrorFull(virConnectPtr conn, errorMessage[0] = '\0'; } - if (virAsprintf(&combined, "%s: %s", errorMessage, theerrnostr) < 0) - combined = theerrnostr; /* OOM, so lets just pass the strerror info as best effort */ + char *err_str; + int n = snprintf(combined, sizeof combined, "%s: %s", + errorMessage, theerrnostr); + err_str = (0 < n && n < sizeof(combined) + ? combined + /* use the strerror info as best effort */ + : theerrnostr); - virerr = virErrorMsg(VIR_ERR_SYSTEM_ERROR, (errorMessage[0] ? errorMessage : NULL)); + virerr = virErrorMsg(VIR_ERR_SYSTEM_ERROR, (err_str[0] ? err_str : NULL)); virRaiseError(conn, NULL, NULL, domcode, VIR_ERR_SYSTEM_ERROR, VIR_ERR_ERROR, virerr, errorMessage, NULL, -1, -1, virerr, errorMessage); } -- 1.6.1.1.347.g3f81d