linux-kernel - Re: [RFC PATCH] sched: Add missing memory barrier in switch_mm

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID:
 <AM0PR08MB428936EACB47856176BFDD8CFB242@AM0PR08MB4289.eurprd08.prod.outlook.com>
Date: Mon, 11 Mar 2024 08:45:07 +0000
From: Yeo Reum Yun <YeoReum.Yun@....com>
To: Mathieu Desnoyers <mathieu.desnoyers@...icios.com>
CC: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"stable@...r.kernel.org" <stable@...r.kernel.org>, Catalin Marinas
	<Catalin.Marinas@....com>, Mark Rutland <Mark.Rutland@....com>, Will Deacon
	<will@...nel.org>, Peter Zijlstra <peterz@...radead.org>, Aaron Lu
	<aaron.lu@...el.com>
Subject: Re: [RFC PATCH] sched: Add missing memory barrier in switch_mm_cid

Hi. Mathieu. Sorry to late answer.

> diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h
> index 35389b2af88e..0d5e54201eb2 100644
> --- a/arch/x86/include/asm/barrier.h
> +++ b/arch/x86/include/asm/barrier.h
> @@ -79,6 +79,9 @@ do {                                                                  \
>  #define __smp_mb__before_atomic()      do { } while (0)
>  #define __smp_mb__after_atomic()       do { } while (0)

> +/* Writing to CR3 provides a full memory barrier in switch_mm(). */
> +#define smp_mb__after_switch_mm()      do { } while (0)
> +
> #include <asm-generic/barrier.h>

IIUC, ppc already does smp_mb() in switch_mm.

Would it better to add the same macro which do nothing to pcc?\\

Thanks!

IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.