Re: [libvirt] [PATCH] Honor blacklist for modprobe command

https://bugzilla.redhat.com/show_bug.cgi?id=1045124 When loading modules, libvirt does not honor the modprobe blacklist. By adding a "-b" to the modprobe command libvirt will fail to load a module if it's on the blacklist Check if the failure to load a driver was due to it being on the blacklist using the output of a "modprobe -c" searching for "blacklist <driver_Name>" where driver_Name is possibly a modified string of the input driver changing all '-' into '_' since that's what modprobe does. Signed-off-by: John Ferlan <jferlan(a)redhat.com&gt; --- src/util/virpci.c | 48 ++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 42 insertions(+), 6 deletions(-) diff --git a/src/util/virpci.c b/src/util/virpci.c index e2d222e..18b85f2 100644 --- a/src/util/virpci.c +++ b/src/util/virpci.c @@ -979,6 +979,10 @@ virPCIProbeStubDriver(const char *driver) { char *drvpath = NULL; bool probed = false; + size_t i; + char *drvblklst = NULL; + char *outbuf = NULL; + virCommandPtr cmd = NULL; recheck: if (virPCIDriverDir(&drvpath, driver) == 0 && virFileExists(drvpath)) { @@ -990,18 +994,49 @@ recheck: VIR_FREE(drvpath); if (!probed) { - const char *const probecmd[] = { MODPROBE, driver, NULL }; + cmd = virCommandNewArgList(MODPROBE, "-b", driver, NULL); probed = true; - if (virRun(probecmd, NULL) < 0) { + if (virCommandRun(cmd, NULL) < 0) { char ebuf[1024]; VIR_WARN("failed to load driver %s: %s", driver, virStrerror(errno, ebuf, sizeof(ebuf))); - return -1; + goto cleanup; } + virCommandFree(cmd); + cmd = NULL; goto recheck; } + /* All error path code - purpose is to determine whether the failure + * occurs because device is on blacklist in order to add an error + * message to help detect why load failed + */ + if (virAsprintfQuiet(&drvblklst, "blacklist %s", driver) < 0) + goto cleanup; + + /* Although driver may have dash, 'modprobe -c' adjusts to use underscore */ + for (i = 0; i < drvblklst[i]; i++) + if (drvblklst[i] == '-') + drvblklst[i] = '_'; + + cmd = virCommandNewArgList(MODPROBE, "-c", NULL); + virCommandSetOutputBuffer(cmd, &outbuf); + if (virCommandRun(cmd, NULL) < 0) + goto cleanup; + + /* Find driver on blacklist? */ + if (strstr(outbuf, drvblklst)) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Failed to load PCI stub module %s: " + "administratively prohibited"), + driver); + } + +cleanup: + virCommandFree(cmd); + VIR_FREE(drvblklst); + VIR_FREE(outbuf); return -1; }