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| author | Babu Moger <babu.moger@amd.com> | 2021-08-20 16:52:42 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-15 09:50:47 +0200 |
| commit | c6b42ec1c93655f00f4438ed32acb8c84ff127f2 (patch) | |
| tree | 7d8ca70a792507c6ed13035c5ccb06a239c02d17 | |
| parent | bafece6cd1f9908d73be31b534bf91c15fbedd94 (diff) | |
| download | linux-stable-c6b42ec1c93655f00f4438ed32acb8c84ff127f2.tar.gz linux-stable-c6b42ec1c93655f00f4438ed32acb8c84ff127f2.tar.bz2 linux-stable-c6b42ec1c93655f00f4438ed32acb8c84ff127f2.zip | |
x86/resctrl: Fix a maybe-uninitialized build warning treated as error
commit 527f721478bce3f49b513a733bacd19d6f34b08c upstream.
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 <Terry.Bowman@amd.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/162949631908.23903.17090272726012848523.stgit@bmoger-ubuntu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kernel/cpu/resctrl/monitor.c | 6 |
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 3075624723b2..576f16a505e3 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -241,6 +241,12 @@ static u64 __mon_event_count(u32 rmid, struct rmid_read *rr) case QOS_L3_MBM_LOCAL_EVENT_ID: m = &rr->d->mbm_local[rmid]; break; + default: + /* + * Code would never reach here because an invalid + * event id would fail the __rmid_read. + */ + return RMID_VAL_ERROR; } if (rr->first) { |