From: David Gibson <david@gibson.dropbear.id.au>
Date: Wed, 30 Nov 2005 03:34:32 +0000 (-0800)
Subject: [PATCH] Fix crash when ptrace poking hugepage areas
X-Git-Tag: v2.6.15-rc4~4^2~9
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5bd0190bf3d7e53043a048e809ffa29d41b9d6ac;p=pandora-kernel.git

[PATCH] Fix crash when ptrace poking hugepage areas

set_page_dirty() will not cope with being handed a page * which is part of
a compound page, but not the master page in that compound page.  This case
can occur via access_process_vm() if you attemp to write to another
process's hugepage memory area using ptrace() (causing an oops or hang).

This patch fixes the bug by only calling set_page_dirty() from
access_process_vm() if the page is not a compound page.  We already use a
similar fix in bio_set_pages_dirty() for the case of direct io to
hugepages.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: William Irwin <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

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