Re: [PATCH] x86-64 singlestep through sigreturn system call

[Andi Kleen]

Roland McGrath <roland@xxxxxxxxxx> writes:

>> Anyways, even if I applied your patch there would be still inconsistency
>> because there are several other system calls that use IRET. So I don't
>> see much advantage in adding a special case just for sigreturn.
>
> Now that I see that the difference is due to iret being used, I have a
> different solution that handles all cases.  The following patch replaces
> both my previous patch for x86-64 native behavior and my patch for x86-64's
> ia32 support.  This patch just directly clones Davide Libenzi's i386 code
> for x86-64 in both 64-bit and 32-bit cases.  With this, the behavior of
> single-stepping all system calls is consistent.  

Hmm, but now the behaviour for 32bit processes is different from the
native 32bit kernel, since 32bit didn't apply any patch so far AFAIK.

If you send me a patch that just changes the behaviour of 64bit 
IRET I would apply it.

-Andi

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/