From 5bc64bd246ca00e0bb0b7137afaf586f2f66a911 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Sat, 8 Jul 2017 23:25:14 +0200 Subject: parisc: Disable further stack checks when panic occurs during stack check 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 Signed-off-by: Helge Deller --- arch/parisc/kernel/irq.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) 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 @@ check_kernel_stack: #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 } -- cgit v1.1