linux-kernel - Re: [PATCH FIXED] x86: use flush_tlb_others to implement flush_tlb

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] [day] [month] [year] [list]

Message-ID: <4A0B0516.8010104@goop.org>
Date:	Wed, 13 May 2009 10:36:22 -0700
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	Ian Campbell <Ian.Campbell@...citrix.com>
CC:	"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...e.hu>,
	the arch/x86 maintainers <x86@...nel.org>,
	Xen-devel <xen-devel@...ts.xensource.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH FIXED] x86: use flush_tlb_others to implement	flush_tlb_all

Ian Campbell wrote:
> get_cpu() returns smp_processor_id() so wouldn't this be more normally
> written as:
> 	/* flush_tlb_others expects preempt to be disabled */
> 	unsigned long cpu = get_cpu();
> 	[....]
> 	if ([....] == TLBSTATE_LAZY)
> 		leave_mm(cpu)
> 	put_cpu();
>   

Quite so.  In theory gcc should be able to CSE smp_processor_id(), but 
the intent of get_cpu() is that you use its return value...

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