linux-kernel - Re: [PATCH V6 04/11] compiler_types.h: Add __noinstr

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Y1aBshGIWMEm+yTv@FVFF77S0Q05N>
Date:   Mon, 24 Oct 2022 13:14:42 +0100
From:   Mark Rutland <mark.rutland@....com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Guo Ren <guoren@...nel.org>,
        Lai Jiangshan <laijs@...ux.alibaba.com>, arnd@...db.de,
        palmer@...osinc.com, tglx@...utronix.de, luto@...nel.org,
        conor.dooley@...rochip.com, heiko@...ech.de, jszhang@...nel.org,
        lazyparser@...il.com, falcon@...ylab.org, chenhuacai@...nel.org,
        apatel@...tanamicro.com, atishp@...shpatra.org, palmer@...belt.com,
        paul.walmsley@...ive.com, zouyipeng@...wei.com,
        bigeasy@...utronix.de, David.Laight@...lab.com,
        chenzhongjin@...wei.com, linux-arch@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-riscv@...ts.infradead.org,
        Borislav Petkov <bp@...en8.de>,
        Miguel Ojeda <ojeda@...nel.org>,
        Kees Cook <keescook@...omium.org>,
        Nick Desaulniers <ndesaulniers@...gle.com>
Subject: Re: [PATCH V6 04/11] compiler_types.h: Add __noinstr_section() for
 noinstr

On Mon, Oct 24, 2022 at 02:06:04PM +0200, Peter Zijlstra wrote:
> On Mon, Oct 24, 2022 at 12:56:03PM +0100, Mark Rutland wrote:
> 
> > How about we split this like:
> > 
> > | /*
> > |  * Prevent the compiler from instrumenting this code in any way
> > |  * This does not prevent instrumentation via KPROBES, which must be
> > |  * prevented through other means if necessary.
> 
> Perhaps point to NOINSTR_TEXT in vmlinux.lds.h

Makes sense, will do.

> 
> > |  */
> > | #define __no_compiler_instrument				\
> > | 	noinline notrace noinline notrace __no_kcsan		\
> > | 	__no_sanitize_address __no_sanitize_coverage
> > | 
> > | /* 
> > |  * Section for code which can't be instrumented at all.
> > |  * Any code in this section cannot be instrumented with KPROBES.
> > |  */
> > | #define noinstr __no_compiler_instrument section(".noinstr.text")
> > 
> > ... then we don't need __noinstr_section(), and IMO the split is
> > clearer.
> 
> Yeah, perhaps, no strong feelings. Note I have this in the sched-idle
> series as well (which I still need to rebase and repost :/).

Ah; I'll sit on this for now then, and once that's all in I can send a
cleanup/rework patch. Sorry for the noise!

Thanks,
Mark.