path: root/arch
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authorBabu Moger <>2021-08-20 16:52:42 -0500
committerBorislav Petkov <>2021-08-22 09:11:29 +0200
commit527f721478bce3f49b513a733bacd19d6f34b08c (patch)
treebb3886da69b6be7012176bd260992f6db550f469 /arch
parent22aa45cb465be474e97666b3f7587ccb06ee411b (diff)
x86/resctrl: Fix a maybe-uninitialized build warning treated as error
The recent commit 064855a69003 ("x86/resctrl: Fix default monitoring groups reporting") caused a RHEL build failure with an uninitialized variable warning treated as an error because it removed the default case snippet. The RHEL Makefile uses '-Werror=maybe-uninitialized' to force possibly uninitialized variable warnings to be treated as errors. This is also reported by smatch via the 0day robot. The error from the RHEL build is: arch/x86/kernel/cpu/resctrl/monitor.c: In function ‘__mon_event_count’: arch/x86/kernel/cpu/resctrl/monitor.c:261:12: error: ‘m’ may be used uninitialized in this function [-Werror=maybe-uninitialized] m->chunks += chunks; ^~ The upstream Makefile does not build using '-Werror=maybe-uninitialized'. So, the problem is not seen there. Fix the problem by putting back the default case snippet. [ bp: note that there's nothing wrong with the code and other compilers do not trigger this warning - this is being done just so the RHEL compiler is happy. ] Fixes: 064855a69003 ("x86/resctrl: Fix default monitoring groups reporting") Reported-by: Terry Bowman <> Reported-by: kernel test robot <> Signed-off-by: Babu Moger <> Signed-off-by: Borislav Petkov <> Reviewed-by: Reinette Chatre <> Cc: Link:
Diffstat (limited to 'arch')
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 57e4bb695ff9..8caf871b796f 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -304,6 +304,12 @@ static u64 __mon_event_count(u32 rmid, struct rmid_read *rr)
m = &rr->d->mbm_local[rmid];
+ default:
+ /*
+ * Code would never reach here because an invalid
+ * event id would fail the __rmid_read.
+ */
+ return RMID_VAL_ERROR;
if (rr->first) {