linux-kernel - [PATCH 1/1] perf/x86/intel: Fix static checker warning in lbr enable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 14 Sep 2015 10:14:07 -0400
From:	kan.liang@...el.com
To:	a.p.zijlstra@...llo.nl
Cc:	dan.carpenter@...cle.com, kernel-janitors@...r.kernel.org,
	linux-kernel@...r.kernel.org, Kan Liang <kan.liang@...el.com>
Subject: [PATCH 1/1] perf/x86/intel: Fix static checker warning in lbr enable

From: Kan Liang <kan.liang@...el.com>

The 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)

This patch is to fix this warning.

Reported-by: Dan Carpenter <dan.carpenter@...cle.com>
Signed-off-by: Kan Liang <kan.liang@...el.com>
---
 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);
-- 
1.8.3.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/