From: Andrew Morton <akpm@linux-foundation.org>
Date: Sat, 5 Jul 2008 08:02:01 +0000 (-0700)
Subject: Fix pagemap_read() use of struct mm_walk
X-Git-Tag: v2.6.26-rc9~1
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=5d7e0d2bd98ef4f5a16ac9da1987ae655368dd6a;hp=5d7e0d2bd98ef4f5a16ac9da1987ae655368dd6a;ds=sidebyside

Fix pagemap_read() use of struct mm_walk

Fix some issues in pagemap_read noted by Alexey:

- initialize pagemap_walk.mm to "mm" , so the code starts working as
  advertised

- initialize ->private to "&pm" so it wouldn't immediately oops in
  pagemap_pte_hole()

- unstatic struct pagemap_walk, so two threads won't fsckup each other
  (including those started by root, including flipping ->mm when you don't
  have permissions)

- pagemap_read() contains two calls to ptrace_may_attach(), second one
  looks unneeded.

- avoid possible kmalloc(0) and integer wraparound.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Personally, I'd just remove the functionality entirely  - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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