* Xiaotian Feng [off-list ref] wrote:

On Thu, Dec 23, 2010 at 5:35 AM,  [off-list ref] wrote:

quoted

On Wed, 22 Dec 2010 13:40:19 +0100, Ingo Molnar said:

quoted

* mat [off-list ref] wrote:

quoted

Le Wed, 8 Dec 2010 14:19:51 -0800,
Kees Cook [off-list ref] a écrit :

quoted

On Fri, Nov 26, 2010 at 06:23:55PM +0100, mat wrote:

quoted

could you try the attached patch ?

on module load, we sort the __jump_table section. So we should make
it writable.


Matthieu

quoted

diff --git a/arch/x86/include/asm/jump_label.h

b/arch/x86/include/asm/jump_label.h index f52d42e..574dbc2 100644

--- a/arch/x86/include/asm/jump_label.h
+++ b/arch/x86/include/asm/jump_label.h

@@ -14,7 +14,7 @@

        do
{                                                       \ asm
goto("1:"                                       \
JUMP_LABEL_INITIAL_NOP                  \
-                       ".pushsection __jump_table,  \"a\" \n\t"\
+                       ".pushsection __jump_table,  \"aw\" \n\t"\
                        _ASM_PTR "1b, %l[" #label "], %c0 \n\t" \
                        ".popsection \n\t"                      \
                        : :  "i" (key) :  : label);
\

Acked-by: Kees Cook <redacted>

Can this please get committed to tip?

I think it is not need anymore with  Steven Rostedt patch [1]

Matthieu

[1]

quoted

quoted

Here we set the text read only before we call the notifiers. The
function tracer changes the calls to mcount into nops via a notifier
call so this must be done after the module notifiers.

What's the status of this bug?

If we still need the patch then please submit it standalone with a proper subject
line, with acks/signoffs added, etc.

Steve Rostedt's patch that moves the setting of the page permissions seems to
make this patch no longer necessary.  I tripped over this same issue, but the
version in the latest -mmotm does not need it, as it includes Steve's fix.

I'm facing a boot failure (panic'ed on remove_jump_label_module_init)
on 2.6.37 (latest commit 3c0cb7c), which is 100% reproducible.
With this patch applied, I can boot my machine successfully, so I do
think this patch is needed.

That would be commit:

 94462ad3b147: module: Move RO/NX module protection to after ftrace module update

So if commit 3c0cb7c is still broken, it has 94462ad3b147 included already, and 
there's some other bug. Kees, Steve, any ideas?

Xiaotian, please post as much about the crash as you can - a log/picture of the boot 
crash that occurs would be good.

Thanks,

	Ingo