linux-kernel - Re: [PATCH] fix bogus hotplug cpu warning

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: <20070827135212.6a5a847e.akpm@linux-foundation.org>
Date:	Mon, 27 Aug 2007 13:52:12 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Hugh Dickins <hugh@...itas.com>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] fix bogus hotplug cpu warning

On Mon, 27 Aug 2007 21:37:14 +0100 (BST)
Hugh Dickins <hugh@...itas.com> wrote:

> > So I agree with the patch, but not with its description.
> 
> I don't see which part of the description you disagree with, but please
> do improve it if you can.

I'd change the description to


current_is_keventd() is a stupid load of crap.  It does

int current_is_keventd(void)
{
	struct cpu_workqueue_struct *cwq;
	int cpu = smp_processor_id();	/* preempt-safe: keventd is per-cpu */

but that comment (and the code itself) only make sense when
current_is_keventd() is called by keventd.  In which case thers is no point
in the function even existing!

We need to use raw_smp_processor_id() so that non-keventd (or, more
specifically, non-pinned-to-one-cpu) callers won't generate "using
smp_processor_id() in preemptible" warnings.

-
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/