[PATCH] sched/cpuacct: Check for NULL when using task_pt_regs()
From: Anton Blanchard <hidden>
Date: 2016-04-13 08:19:07
Also in:
lkml
Subsystem:
scheduler, the rest · Maintainers:
Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds
task_pt_regs() can return NULL for kernel threads, so add a check.
This fixes an oops at boot on ppc64.
Fixes: d740037fac70 ("sched/cpuacct: Split usage accounting into user_usage and sys_usage")
Signed-off-by: Anton Blanchard <redacted>
Reported-and-Tested-by: Srikar Dronamraju <redacted>
---
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index df947e0..41f85c4 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c@@ -316,12 +316,11 @@ static struct cftype files[] = { void cpuacct_charge(struct task_struct *tsk, u64 cputime) { struct cpuacct *ca; - int index; + int index = CPUACCT_USAGE_SYSTEM; + struct pt_regs *regs = task_pt_regs(tsk); - if (user_mode(task_pt_regs(tsk))) + if (regs && user_mode(regs)) index = CPUACCT_USAGE_USER; - else - index = CPUACCT_USAGE_SYSTEM; rcu_read_lock();