linux-kernel - Re: mmap hw behavior

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]

Date:	Wed, 08 Jul 2009 10:35:20 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	michal.simek@...alogix.com
Cc:	linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
	mingo@...e.hu, arnd@...db.de, lethal@...ux-sh.org,
	ltp-list@...ts.sourceforge.net
Subject: Re: mmap hw behavior

From: Michal Simek <michal.simek@...alogix.com>
Date: Wed, 08 Jul 2009 19:03:11 +0200

> When I call mmap for that open file with pointer to calloc place
> (first parameter, + length zero) it should be one tlb invalidation
> for calloc and new tlb which connect open file.  We check it and we
> don't have any tlb invalidation that's why I think that kernel do
> different thigs.  Or is it there any copying? Or anything different?

There is no need to tlb flush the calloc area unless that memory area
is actually touched by the user application and thus the page is
faulted in.
--
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/