linux-kernel - [PATCH] MIPS: smp-cps: Fix potentially uninitialised value of core

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Message-ID: <1490957468-27255-1-git-send-email-matt.redfearn@imgtec.com>
Date:   Fri, 31 Mar 2017 11:51:08 +0100
From:   Matt Redfearn <matt.redfearn@...tec.com>
To:     Ralf Baechle <ralf@...ux-mips.org>,
        James Hogan <james.hogan@...tec.com>
CC:     <linux-mips@...ux-mips.org>,
        Matt Redfearn <matt.redfearn@...tec.com>,
        Masahiro Yamada <yamada.masahiro@...ionext.com>,
        <linux-kernel@...r.kernel.org>,
        Paul Burton <paul.burton@...tec.com>,
        Ingo Molnar <mingo@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH] MIPS: smp-cps: Fix potentially uninitialised value of core

Turning on DEBUG in smp-cps.c, or compiling the kernel with
CONFIG_DYNAMIC_DEBUG enabled results the build error:

arch/mips/kernel/smp-cps.c: In function 'play_dead':
./include/linux/dynamic_debug.h:126:3: error: 'core' may be used
uninitialized in this function [-Werror=maybe-uninitialized]

Fix this by always initialising the variable.

Fixes: 0d2808f338c7 ("MIPS: smp-cps: Add support for CPU hotplug of MIPSr6 processors")
Signed-off-by: Matt Redfearn <matt.redfearn@...tec.com>

---

 arch/mips/kernel/smp-cps.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index 6d45f05538c8..795b4aaf8927 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -422,13 +422,12 @@ void play_dead(void)
 	local_irq_disable();
 	idle_task_exit();
 	cpu = smp_processor_id();
+	core = cpu_data[cpu].core;
 	cpu_death = CPU_DEATH_POWER;
 
 	pr_debug("CPU%d going offline\n", cpu);
 
 	if (cpu_has_mipsmt || cpu_has_vp) {
-		core = cpu_data[cpu].core;
-
 		/* Look for another online VPE within the core */
 		for_each_online_cpu(cpu_death_sibling) {
 			if (cpu_data[cpu_death_sibling].core != core)
-- 
2.7.4