Re: [RFC/PATCH 3/7] [TEMPORARY] x86/entry/32: Sanity check for work_notifysig

From: Andy Lutomirski
Date: Wed Jul 08 2015 - 15:26:08 EST


[cc: Al -- saying I'm cc-ing you in the patch 0 description doesn't make it so.]

On Wed, Jul 8, 2015 at 12:24 PM, Andy Lutomirski <luto@xxxxxxxxxx> wrote:
> 44fbbb3dc687c added an unnecessary check. Add a temporary assertion
> to confirm that it's unnecessary.
>
> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
> ---
> arch/x86/entry/entry_32.S | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
> index a36d5df6a749..d36afad80ad1 100644
> --- a/arch/x86/entry/entry_32.S
> +++ b/arch/x86/entry/entry_32.S
> @@ -491,10 +491,13 @@ work_notifysig: # deal with pending signals and
> #endif
> TRACE_IRQS_ON
> ENABLE_INTERRUPTS(CLBR_NONE)
> + /* Temporary sanity check */
> movb PT_CS(%esp), %bl
> andb $SEGMENT_RPL_MASK, %bl
> cmpb $USER_RPL, %bl
> - jb resume_kernel
> + jnb 2f
> + ud2
> +2:
> xorl %edx, %edx
> call do_notify_resume
> jmp resume_userspace
> --
> 2.4.3
>



--
Andy Lutomirski
AMA Capital Management, LLC
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