linux-kernel - Re: missing madvise functionality

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]

Date:	03 Apr 2007 20:14:29 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	Ulrich Drepper <drepper@...hat.com>
Cc:	Rik van Riel <riel@...hat.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linux Kernel <linux-kernel@...r.kernel.org>,
	Jakub Jelinek <jakub@...hat.com>
Subject: Re: missing madvise functionality

Ulrich Drepper <drepper@...hat.com> writes:

>   to free:      mmap(PROT_NONE) over the area

Why do you need a lock for that? I don't see any problem with
two threads doing that in parallel. The kernel would
serialize it internally and one would fail, but that shouldn't
be a problem. 

Of course having the lock should also not make much difference --
if glibc doesn't do it then it kernel would anyways and run
into the same scalability issue on mmap_sem.

-Andi

-
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/