linux-kernel - Re: [PATCH] mm: D-cache aliasing issue in cow_user

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: <20061205.132412.116353924.davem@davemloft.net>
Date:	Tue, 05 Dec 2006 13:24:12 -0800 (PST)
From:	David Miller <davem@...emloft.net>
To:	mattjreimer@...il.com
Cc:	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mm: D-cache aliasing issue in cow_user_page

From: "Matt Reimer" <mattjreimer@...il.com>
Date: Mon, 4 Dec 2006 23:38:13 -0800

> In light of James Bottomsley's commit[1] declaring that kmap() and
> friends now have to take care of coherency issues, is the patch "mm:
> D-cache aliasing issue in cow_user_page"[2] correct, or could it
> potentially cause a slowdown by calling flush_dcache_page() a second
> time (i.e. once in an architecture-specific kmap() implementation, and
> once in cow_user_page())?

kmap() is a NOP unless HIGHMEM is configured.

Therefore, it cannot possibly take care of D-cache aliasing issues
across the board.
-
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/