| From | Andy Lutomirski <> | Date | Thu, 21 Jul 2016 14:56:52 -0700 | Subject | Re: [PATCH 03/19] x86/dumpstack: remove unnecessary stack pointer arguments |
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On Thu, Jul 21, 2016 at 2:21 PM, Josh Poimboeuf <jpoimboe@redhat.com> wrote: > When calling show_stack_log_lvl() or dump_trace() with a regs argument, > providing a stack pointer or frame pointer is redundant. >
> diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c > index 358fe1c..c533b8b 100644 > --- a/arch/x86/kernel/dumpstack_32.c > +++ b/arch/x86/kernel/dumpstack_32.c > @@ -122,7 +122,7 @@ void show_regs(struct pt_regs *regs) > u8 *ip; > > pr_emerg("Stack:\n"); > - show_stack_log_lvl(NULL, regs, ®s->sp, 0, KERN_EMERG); > + show_stack_log_lvl(NULL, regs, NULL, 0, KERN_EMERG);
This is weird -- note the &. You're at some risk of exposing a bug in x86_32's kernel_stack_pointer() function, which is a mess. (I don't see why it's written the way it is -- the actual return stack pointer given a pt_regs is quite well defined -- if regs->cs & 3 != 0, then it's regs->sp, else it's ®s->sp.)
That being said, this isn't a big deal, so:
Reviewed-by: Andy Lutomirski <luto@kernel.org>
If you want to make this all a bit more reliably on x86_32, you could fix kernel_stack_pointer().
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