On Wed, Mar 22, 2017 at 09:47:06AM +0100, Peter Zijlstra wrote:
>
> A little like so then.
>
> ---
> Subject: x86: Implement __WARN using UD0
> From: Peter Zijlstra
> Date: Thu Feb 2 14:43:51 CET 2017
>
> By using "UD0" for WARNs we remove the function call and its possible
> __FILE__ and __LIN
A little like so then.
---
Subject: x86: Implement __WARN using UD0
From: Peter Zijlstra
Date: Thu Feb 2 14:43:51 CET 2017
By using "UD0" for WARNs we remove the function call and its possible
__FILE__ and __LINE__ immediate arguments from the instruction stream.
Total image size will not chan
On Tue, Mar 21, 2017 at 09:03:40AM -0500, Josh Poimboeuf wrote:
> On Fri, Mar 17, 2017 at 10:19:19PM +0100, Peter Zijlstra wrote:
> > +/*
> > + * Since some emulators terminate on UD2, we cannot use it for WARN.
> > + * Since various instruction decoders disagree on the length of UD1,
> > + * we c
On Tue, Mar 21, 2017 at 10:32:52AM -0500, Josh Poimboeuf wrote:
> On Tue, Mar 21, 2017 at 04:14:46PM +0100, Peter Zijlstra wrote:
> > > > +static int fixup_bug(struct pt_regs *regs, int trapnr)
> > > > +{
> > > > + if (trapnr != X86_TRAP_UD)
> > > > + return 0;
> > > > +
> > > >
On Tue, Mar 21, 2017 at 04:14:46PM +0100, Peter Zijlstra wrote:
> > to WARN, they should probably be renamed to describe their new purpose,
> > like:
> >
> > "report_bug" -> "report_bug_or_warning"
> > "fixup_bug" -> "fixup_bug_or_warning"
> >
> > On a related note, if warn and bug are going
On 3/21/2017 8:14 AM, Peter Zijlstra wrote:
For self-documentation purposes, maybe use a define for the length of
the ud0 instruction?
#define TWO 2
;-)
some things make sense as a define, others don't
(adding a comment, maybe)
On Fri, Mar 17, 2017 at 10:19:19PM +0100, Peter Zijlstra wrote:
> --- a/arch/x86/include/asm/bug.h
> +++ b/arch/x86/include/asm/bug.h
> @@ -1,36 +1,70 @@
> #ifndef _ASM_X86_BUG_H
> #define _ASM_X86_BUG_H
>
> +#include
> +
> #define HAVE_ARCH_BUG
>
> -#ifdef CONFIG_DEBUG_BUGVERBOSE
> +/*
> +
By using "UD0" for WARNs we remove the function call and its possible
__FILE__ and __LINE__ immediate arguments from the instruction stream.
Total image size will not change much, what we win in the instruction
stream we'll loose because of the __bug_table entries. Still, saves on
I$ footprint and
8 matches
Mail list logo