Messages in this thread Patch in this message | | | Date | Fri, 18 Sep 2015 01:49:33 -0700 | From | tip-bot for Kan Liang <> | Subject | [tip:perf/core] perf/x86/intel: Fix static checker warning in lbr enable |
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Commit-ID: 96f3eda67fcf2598e9d2794398e0e7ab35138ea6 Gitweb: http://git.kernel.org/tip/96f3eda67fcf2598e9d2794398e0e7ab35138ea6 Author: Kan Liang <kan.liang@intel.com> AuthorDate: Mon, 14 Sep 2015 10:14:07 -0400 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Fri, 18 Sep 2015 09:24:57 +0200
perf/x86/intel: Fix static checker warning in lbr enable
Commit deb27519bf1f ("perf/x86/intel: Fix LBR callstack issue caused by FREEZE_LBRS_ON_PMI") leads to the following Smatch complaint:
warn: variable dereferenced before check 'cpuc->lbr_sel' (see line 154)
Fix the warning.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: deb27519bf1f ("perf/x86/intel: Fix LBR callstack issue caused by FREEZE_LBRS_ON_PMI") Link: http://lkml.kernel.org/r/1442240047-48149-1-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/kernel/cpu/perf_event_intel_lbr.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c index a1d07c7..ad0b8b0 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c +++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c @@ -151,8 +151,9 @@ static void __intel_pmu_lbr_enable(bool pmi) * No need to reprogram LBR_SELECT in a PMI, as it * did not change. */ - lbr_select = cpuc->lbr_sel->config; - if (cpuc->lbr_sel && !pmi) + if (cpuc->lbr_sel) + lbr_select = cpuc->lbr_sel->config; + if (!pmi) wrmsrl(MSR_LBR_SELECT, lbr_select); rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
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