On Thu, Sep 16, 2021 at 10:00:15AM +0200, Peter Zijlstra wrote: > On Thu, Sep 16, 2021 at 11:47:49AM +0800, 王贇 wrote: > > > I did some debug and found the issue, we are missing: > > > > @@ -122,7 +137,10 @@ static __always_inline bool in_exception_stack(unsigned long *stack, struct stac > > info->type = ep->type; > > info->begin = (unsigned long *)begin; > > info->end = (unsigned long *)end; > > - info->next_sp = (unsigned long *)regs->sp; > > + > > + if (!(ep->type & STACK_TYPE_GUARD)) > > + info->next_sp = (unsigned long *)regs->sp; > > + > > return true; > > } > > > > as the guard page are not working as real stack I guess? > > Correct, but I thought I put if (type & GUARD) terminators in all paths > that ended up caring about ->next_sp. Clearly I seem to have missed one > :/ > > Let me try and figure out where that happens. Oh, I'm an idiot... yes it tries to read regs the stack, but clearly that won't work for the guard page.
