Commit 96f3eda6 authored Sep 14, 2015 by Kan Liang Committed by Ingo Molnar Sep 18, 2015

perf/x86/intel: Fix static checker warning in lbr enable



Commit deb27519 ("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: deb27519 ("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>

parent 02386c35

arch/x86/kernel/cpu/perf_event_intel_lbr.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -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.
		*/
		if (cpuc->lbr_sel)
		lbr_select = cpuc->lbr_sel->config;
		if (cpuc->lbr_sel && !pmi)
		if (!pmi)
		wrmsrl(MSR_LBR_SELECT, lbr_select);

		rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);