[PATCH v2] qemu: Pass / fill niothreads for qemuMonitorGetIOThreads

Let's pass along / fill @niothreads rather than trying to make dual use as a return value and thread count. This resolves a Coverity issue detected in qemuDomainGetIOThreadsMon where if qemuDomainObjExitMonitor failed, then a -1 was returned and overwrite @niothreads causing a memory leak. Signed-off-by: John Ferlan <jferlan(a)redhat.com&gt; --- Since v1, updated the logic to pass @niothreads around rather than rely on the dual meaning. Took the full plunge. src/qemu/qemu_driver.c | 23 +++++++++++------------ src/qemu/qemu_monitor.c | 8 +++++--- src/qemu/qemu_monitor.h | 3 ++- src/qemu/qemu_monitor_json.c | 6 ++++-- src/qemu/qemu_monitor_json.h | 3 ++- src/qemu/qemu_process.c | 4 ++-- tests/qemumonitorjsontest.c | 4 ++-- 7 files changed, 28 insertions(+), 23 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index bca1c84630..65725b2ef2 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -4972,17 +4972,18 @@ qemuDomainGetMaxVcpus(virDomainPtr dom) static int qemuDomainGetIOThreadsMon(virQEMUDriverPtr driver, virDomainObjPtr vm, - qemuMonitorIOThreadInfoPtr **iothreads) + qemuMonitorIOThreadInfoPtr **iothreads, + int *niothreads) { qemuDomainObjPrivatePtr priv = vm->privateData; - int niothreads = 0; + int ret = -1; qemuDomainObjEnterMonitor(driver, vm); - niothreads = qemuMonitorGetIOThreads(priv->mon, iothreads); - if (qemuDomainObjExitMonitor(driver, vm) < 0 || niothreads < 0) + ret = qemuMonitorGetIOThreads(priv->mon, iothreads, niothreads); + if (qemuDomainObjExitMonitor(driver, vm) < 0) return -1; - return niothreads; + return ret; } @@ -5014,7 +5015,7 @@ qemuDomainGetIOThreadsLive(virQEMUDriverPtr driver, goto endjob; } - if ((niothreads = qemuDomainGetIOThreadsMon(driver, vm, &iothreads)) < 0) + if ((ret = qemuDomainGetIOThreadsMon(driver, vm, &iothreads, &niothreads)) < 0) goto endjob; /* Nothing to do */ @@ -5314,8 +5315,7 @@ qemuDomainHotplugAddIOThread(virQEMUDriverPtr driver, * IOThreads thread_id's, adjust the cgroups, thread affinity, * and add the thread_id to the vm->def->iothreadids list. */ - if ((new_niothreads = qemuMonitorGetIOThreads(priv->mon, - &new_iothreads)) < 0) + if (qemuMonitorGetIOThreads(priv->mon, &new_iothreads, &new_niothreads) < 0) goto exit_monitor; if (qemuDomainObjExitMonitor(driver, vm) < 0) @@ -5425,8 +5425,7 @@ qemuDomainHotplugDelIOThread(virQEMUDriverPtr driver, if (rc < 0) goto exit_monitor; - if ((new_niothreads = qemuMonitorGetIOThreads(priv->mon, - &new_iothreads)) < 0) + if (qemuMonitorGetIOThreads(priv->mon, &new_iothreads, &new_niothreads) < 0) goto exit_monitor; if (qemuDomainObjExitMonitor(driver, vm) < 0) @@ -18507,7 +18506,7 @@ qemuDomainGetStatsIOThread(virQEMUDriverPtr driver, qemuDomainObjPrivatePtr priv = dom->privateData; size_t i; qemuMonitorIOThreadInfoPtr *iothreads = NULL; - int niothreads; + int niothreads = 0; int ret = -1; if (!HAVE_JOB(privflags) || !virDomainObjIsActive(dom)) @@ -18516,7 +18515,7 @@ qemuDomainGetStatsIOThread(virQEMUDriverPtr driver, if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_OBJECT_IOTHREAD)) return 0; - if ((niothreads = qemuDomainGetIOThreadsMon(driver, dom, &iothreads)) < 0) + if (qemuDomainGetIOThreadsMon(driver, dom, &iothreads, &niothreads) < 0) return -1; /* qemuDomainGetIOThreadsMon returns a NULL-terminated list, so we must free diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index ce1a06c4c8..551b65e778 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -4211,22 +4211,24 @@ qemuMonitorRTCResetReinjection(qemuMonitorPtr mon) * qemuMonitorGetIOThreads: * @mon: Pointer to the monitor * @iothreads: Location to return array of IOThreadInfo data + * @niothreads: Count of the number of IOThreads in the array * * Issue query-iothreads command. * Retrieve the list of iothreads defined/running for the machine * - * Returns count of IOThreadInfo structures on success + * Returns 0 on success * -1 on error. */ int qemuMonitorGetIOThreads(qemuMonitorPtr mon, - qemuMonitorIOThreadInfoPtr **iothreads) + qemuMonitorIOThreadInfoPtr **iothreads, + int *niothreads) { VIR_DEBUG("iothreads=%p", iothreads); QEMU_CHECK_MONITOR(mon); - return qemuMonitorJSONGetIOThreads(mon, iothreads); + return qemuMonitorJSONGetIOThreads(mon, iothreads, niothreads); } diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h index 8bc092870b..49be2d5412 100644 --- a/src/qemu/qemu_monitor.h +++ b/src/qemu/qemu_monitor.h @@ -1365,7 +1365,8 @@ struct _qemuMonitorIOThreadInfo { bool set_poll_shrink; }; int qemuMonitorGetIOThreads(qemuMonitorPtr mon, - qemuMonitorIOThreadInfoPtr **iothreads); + qemuMonitorIOThreadInfoPtr **iothreads, + int *niothreads); int qemuMonitorSetIOThread(qemuMonitorPtr mon, qemuMonitorIOThreadInfoPtr iothreadInfo); diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index 5acc1a10aa..f70490d9b0 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -8072,7 +8072,8 @@ qemuMonitorJSONRTCResetReinjection(qemuMonitorPtr mon) */ int qemuMonitorJSONGetIOThreads(qemuMonitorPtr mon, - qemuMonitorIOThreadInfoPtr **iothreads) + qemuMonitorIOThreadInfoPtr **iothreads, + int *niothreads) { int ret = -1; virJSONValuePtr cmd; @@ -8149,9 +8150,10 @@ qemuMonitorJSONGetIOThreads(qemuMonitorPtr mon, info->poll_valid = true; } - ret = n; + *niothreads = n; *iothreads = infolist; infolist = NULL; + ret = 0; cleanup: if (infolist) { diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h index d2928b0ffc..4eb0f667a2 100644 --- a/src/qemu/qemu_monitor_json.h +++ b/src/qemu/qemu_monitor_json.h @@ -550,7 +550,8 @@ int qemuMonitorJSONGetGuestCPU(qemuMonitorPtr mon, int qemuMonitorJSONRTCResetReinjection(qemuMonitorPtr mon); int qemuMonitorJSONGetIOThreads(qemuMonitorPtr mon, - qemuMonitorIOThreadInfoPtr **iothreads) + qemuMonitorIOThreadInfoPtr **iothreads, + int *niothreads) ATTRIBUTE_NONNULL(2); int qemuMonitorJSONSetIOThread(qemuMonitorPtr mon, diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 20e90026e1..01afe66ec9 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -2498,10 +2498,10 @@ qemuProcessDetectIOThreadPIDs(virQEMUDriverPtr driver, /* Get the list of IOThreads from qemu */ if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0) goto cleanup; - niothreads = qemuMonitorGetIOThreads(priv->mon, &iothreads); + ret = qemuMonitorGetIOThreads(priv->mon, &iothreads, &niothreads); if (qemuDomainObjExitMonitor(driver, vm) < 0) goto cleanup; - if (niothreads < 0) + if (ret < 0) goto cleanup; if (niothreads != vm->def->niothreadids) { diff --git a/tests/qemumonitorjsontest.c b/tests/qemumonitorjsontest.c index 79ef2a545e..d0c37967d5 100644 --- a/tests/qemumonitorjsontest.c +++ b/tests/qemumonitorjsontest.c @@ -2377,8 +2377,8 @@ testQemuMonitorJSONGetIOThreads(const void *opaque) "}") < 0) goto cleanup; - if ((ninfo = qemuMonitorGetIOThreads(qemuMonitorTestGetMonitor(test), - &info)) < 0) + if (qemuMonitorGetIOThreads(qemuMonitorTestGetMonitor(test), + &info, &ninfo) < 0) goto cleanup; if (ninfo != 2) { -- 2.28.0