Messages in this thread |  | | | Date | Thu, 10 Nov 2011 14:59:10 -0500 | | From | Konrad Rzeszutek Wilk <> | | Subject | Re: [RFC PATCH 4/5] x86: panic on detection of stack overflow |
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On Mon, Nov 07, 2011 at 02:53:08PM +0900, Mitsuo Hayasaka wrote: > Currently, messages are just output on the detection of stack overflow, > which is not sufficient for enterprise systems since it may corrupt data. > To enhance reliability, it is required to stop the systems.
Why not just make the stack_overflow_check() return a value that it should not handle the IRQ and perhaps silence (disable_chip) the IRQ line?
That will still let the system run, albeit .. without certain parts not working right.. So perhaps re-enable the chip later on?
Or is there really no way to recover from this? > > This patch causes a panic according to a sysctl parameter > panic_on_stackoverflow when detecting it. It is disabled by default. > > Signed-off-by: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: "H. Peter Anvin" <hpa@zytor.com> > --- > > arch/x86/kernel/irq_32.c | 2 ++ > arch/x86/kernel/irq_64.c | 16 +++++++++++----- > 2 files changed, 13 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c > index 7209070..e16e99eb 100644 > --- a/arch/x86/kernel/irq_32.c > +++ b/arch/x86/kernel/irq_32.c > @@ -43,6 +43,8 @@ static void print_stack_overflow(void) > { > printk(KERN_WARNING "low stack detected by irq handler\n"); > dump_stack(); > + if (sysctl_panic_on_stackoverflow) > + panic("low stack detected by irq handler - check messages\n"); > } > > #else > diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c > index d720813..f7baedd 100644 > --- a/arch/x86/kernel/irq_64.c > +++ b/arch/x86/kernel/irq_64.c > @@ -69,14 +69,20 @@ static inline void stack_overflow_check(struct pt_regs *regs) > current->comm, curbase, regs->sp, > irq_stack_top, irq_stack_bottom, > estack_top, estack_bottom); > + if (sysctl_panic_on_stackoverflow) > + panic("low stack detected by irq handler - check messages\n"); > #else > - WARN_ONCE(regs->sp >= curbase && > - regs->sp <= curbase + THREAD_SIZE && > - regs->sp < curbase + sizeof(struct thread_info) + > - sizeof(struct pt_regs) + 128, > - > + if (regs->sp >= curbase && > + regs->sp <= curbase + THREAD_SIZE && > + regs->sp < curbase + sizeof(struct thread_info) + > + sizeof(struct pt_regs) + 128) { > + WARN_ONCE(1, > "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n", > current->comm, curbase, regs->sp); > + if (sysctl_panic_on_stackoverflow) > + panic("low stack detected by irq handler - check messages\n"); > + } > + > #endif /* CONFIG_DEBUG_STACKOVERFLOW_DETAIL */ > #endif > } > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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