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authorHans de Goede <hdegoede@redhat.com>2020-03-09 15:01:38 +0100
committerJoerg Roedel <jroedel@suse.de>2020-03-13 14:25:45 +0100
commit96788c7a7f1e7206519d4d736f89a2072dcfe0fc (patch)
tree4a5bd6333e99dbb652c49c8b0b49c84805834971
parent59833696442c674acbbd297772ba89e7ad8c753d (diff)
downloadlinux-96788c7a7f1e7206519d4d736f89a2072dcfe0fc.tar.bz2
iommu/vt-d: dmar_parse_one_rmrr: replace WARN_TAINT with pr_warn + add_taint
Quoting from the comment describing the WARN functions in include/asm-generic/bug.h: * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report * significant kernel issues that need prompt attention if they should ever * appear at runtime. * * Do not use these macros when checking for invalid external inputs The (buggy) firmware tables which the dmar code was calling WARN_TAINT for really are invalid external inputs. They are not under the kernel's control and the issues in them cannot be fixed by a kernel update. So logging a backtrace, which invites bug reports to be filed about this, is not helpful. Some distros, e.g. Fedora, have tools watching for the kernel backtraces logged by the WARN macros and offer the user an option to file a bug for this when these are encountered. The WARN_TAINT in dmar_parse_one_rmrr + another iommu WARN_TAINT, addressed in another patch, have lead to over a 100 bugs being filed this way. This commit replaces the WARN_TAINT("...") call, with a pr_warn(FW_BUG "...") + add_taint(TAINT_FIRMWARE_WORKAROUND, ...) call avoiding the backtrace and thus also avoiding bug-reports being filed about this against the kernel. Fixes: f5a68bb0752e ("iommu/vt-d: Mark firmware tainted if RMRR fails sanity check") Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> Acked-by: Lu Baolu <baolu.lu@linux.intel.com> Cc: stable@vger.kernel.org Cc: Barret Rhoden <brho@google.com> Link: https://lore.kernel.org/r/20200309140138.3753-3-hdegoede@redhat.com BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1808874
-rw-r--r--drivers/iommu/intel-iommu.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 693380355dea..bdcdfff6015b 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4460,14 +4460,16 @@ int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg)
struct dmar_rmrr_unit *rmrru;
rmrr = (struct acpi_dmar_reserved_memory *)header;
- if (rmrr_sanity_check(rmrr))
- WARN_TAINT(1, TAINT_FIRMWARE_WORKAROUND,
+ if (rmrr_sanity_check(rmrr)) {
+ pr_warn(FW_BUG
"Your BIOS is broken; bad RMRR [%#018Lx-%#018Lx]\n"
"BIOS vendor: %s; Ver: %s; Product Version: %s\n",
rmrr->base_address, rmrr->end_address,
dmi_get_system_info(DMI_BIOS_VENDOR),
dmi_get_system_info(DMI_BIOS_VERSION),
dmi_get_system_info(DMI_PRODUCT_VERSION));
+ add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
+ }
rmrru = kzalloc(sizeof(*rmrru), GFP_KERNEL);
if (!rmrru)