On 2021/9/15 下午11:19, Peter Zijlstra wrote: > On Wed, Sep 15, 2021 at 03:34:20PM +0800, 王贇 wrote: >> Hi, Dave, Peter >> >> What if we just increase the stack size when ftrace enabled? > > I think we can do an unconditional increase. But please first test that > guard page patch :-) Nice~ let's focus on the guard one firstly. Regards, Michael Wang > > --- > Subject: x86: Increase exception stack sizes > From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Date: Wed Sep 15 16:19:46 CEST 2021 > > It turns out that a single page of stack is trivial to overflow with > all the tracing gunk enabled. Raise the exception stacks to 2 pages, > which is still half the interrupt stacks, which are at 4 pages. > > Reported-by: Michael Wang <yun.wang@xxxxxxxxxxxxxxxxx> > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > --- > arch/x86/include/asm/page_64_types.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- a/arch/x86/include/asm/page_64_types.h > +++ b/arch/x86/include/asm/page_64_types.h > @@ -15,7 +15,7 @@ > #define THREAD_SIZE_ORDER (2 + KASAN_STACK_ORDER) > #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) > > -#define EXCEPTION_STACK_ORDER (0 + KASAN_STACK_ORDER) > +#define EXCEPTION_STACK_ORDER (1 + KASAN_STACK_ORDER) > #define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER) > > #define IRQ_STACK_ORDER (2 + KASAN_STACK_ORDER) >
