[PATCH] SPARSEMEM incorrectly calculates section number
commit12783b002db1f02c29353c8f698a85514420b9f4
authorMike Kravetz <kravetz@us.ibm.com>
Sat, 20 May 2006 22:00:05 +0000 (20 15:00 -0700)
committerLinus Torvalds <torvalds@g5.osdl.org>
Sun, 21 May 2006 19:59:17 +0000 (21 12:59 -0700)
treed0cec6913308fb34d539192dd0928cd0d7aae714
parentad8f5797302ed389476debcc51b4630f387618b9
[PATCH] SPARSEMEM incorrectly calculates section number

A bad calculation/loop in __section_nr() could result in incorrect section
information being put into sysfs memory entries.  This primarily impacts
memory add operations as the sysfs information is used while onlining new
memory.

Fix suggested by Dave Hansen.

Note that the bug may not be obvious from the patch.  It actually occurs in
the function's return statement:

return (root_nr * SECTIONS_PER_ROOT) + (ms - root);

In the existing code, root_nr has already been multiplied by
SECTIONS_PER_ROOT.

Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
mm/sparse.c