diff mbox

parisc: Disable further stack checks when panic occurs during stack check

Message ID 20170708212514.GA2560@ls3530.fritz.box (mailing list archive)
State Accepted, archived
Headers show

Commit Message

Helge Deller July 8, 2017, 9:25 p.m. UTC 
Before the irq handler detects a low stack and then panics the kernel, disable
further stack checks to avoid recursive panics.

Reported-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>

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diff mbox

Patch

diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
index ba5e1c7..5404e40 100644
--- a/arch/parisc/kernel/irq.c
+++ b/arch/parisc/kernel/irq.c
@@ -413,6 +413,10 @@  static inline void stack_overflow_check(struct pt_regs *regs)
 	if (regs->sr[7])
 		return;
 
+	/* exit if already in panic */
+	if (sysctl_panic_on_stackoverflow < 0)
+		return;
+
 	/* calculate kernel stack usage */
 	stack_usage = sp - stack_start;
 #ifdef CONFIG_IRQSTACKS
@@ -454,8 +458,10 @@  static inline void stack_overflow_check(struct pt_regs *regs)
 #ifdef CONFIG_IRQSTACKS
 panic_check:
 #endif
-	if (sysctl_panic_on_stackoverflow)
+	if (sysctl_panic_on_stackoverflow) {
+		sysctl_panic_on_stackoverflow = -1; /* disable further checks */
 		panic("low stack detected by irq handler - check messages\n");
+	}
 #endif
 }