lkml.org 
[lkml]   [2008]   [Nov]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] x86: KPROBE_ENTRY should be paired wth KPROBE_END

* Alexander van Heukelum <heukelum@mailshack.com> wrote:

> Impact: moves some code out of .kprobes.text
>
> KPROBE_ENTRY switches code generation to .kprobes.text, and KPROBE_END
> uses .popsection to get back to the previous section (.text, normally).
> Also replace ENDPROC by END, for consistency.
>
> Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>

applied to tip/x86/irq, thanks Alexander!

> One more small change for today. The xen-related functions
> xen_do_hypervisor_callback and xen_failsafe_callback are put
> in the .kprobes.text even in the current kernel: ignore_sysret
> is enclosed in KPROBE_ENTRY / ENDPROC, instead of KPROBE_ENTRY /
> KPROBE_END, but I guess the situation is harmless.

yeah. It narrows no-kprobes protection for that code, but it should
indeed be fine (and that's the intention as well).

Note that this is a reoccuring bug type, and rather long-lived. Can
you think of any way to get automated nesting protection of both the
.cfi_startproc/endproc macros and kprobes start/end? A poor man's
solution would be to grep the number of start and end methods and
enforce that they are equal.

Ingo


\
 
 \ /
  Last update: 2008-11-23 14:31    [W:0.777 / U:0.380 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site