lkml.org 
[lkml]   [2021]   [Mar]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH -tip v3 05/11] x86/kprobes: Add UNWIND_HINT_FUNC on kretprobe_trampoline code
On Sat, Mar 20, 2021 at 09:16:16PM +0900, Masami Hiramatsu wrote:
> On Fri, 19 Mar 2021 21:22:39 +0900
> Masami Hiramatsu <mhiramat@kernel.org> wrote:
>
> > From: Josh Poimboeuf <jpoimboe@redhat.com>
> >
> > Add UNWIND_HINT_FUNC on kretporbe_trampoline code so that ORC
> > information is generated on the kretprobe_trampoline correctly.
> >
>
> Test bot also found a new warning for this.
>
> > >> arch/x86/kernel/kprobes/core.o: warning: objtool: kretprobe_trampoline()+0x25: call without frame pointer save/setup
>
> With CONFIG_FRAME_POINTER=y.
>
> Of course this can be fixed with additional "push %bp; mov %sp, %bp" before calling
> trampoline_handler. But actually we know that this function has a bit special
> stack frame too.
>
> Can I recover STACK_FRAME_NON_STANDARD(kretprobe_trampoline) when CONFIG_FRAME_POINTER=y ?

Yes, that's what I'd recommend.

--
Josh

\
 
 \ /
  Last update: 2021-03-21 18:51    [W:0.048 / U:0.144 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site