From: Julia Lawall <julia@diku.dk>
Date: Thu, 17 Jul 2008 19:16:34 +0000 (+0200)
Subject: arch/m68k/mm/sun3mmu.c: Eliminate NULL test and memset after alloc_bootmem
X-Git-Tag: v2.6.27-rc1~973
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=93026e217b46b70f9719caf69e716fa3bbe1d20c;p=linux-2.6

arch/m68k/mm/sun3mmu.c: Eliminate NULL test and memset after alloc_bootmem

As noted by Akinobu Mita in patch b1fceac2b9e04d278316b2faddf276015fc06e3b,
alloc_bootmem and related functions never return NULL and always return a
zeroed region of memory.  Thus a NULL test or memset after calls to these
functions is unnecessary.

This was fixed using the following semantic patch.
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression E;
statement S;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\)(...)
.. when != E
(
- BUG_ON (E == NULL);
|
- if (E == NULL) S
)

@@
expression E,E1;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\)(...)
.. when != E
- memset(E,0,E1);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/arch/m68k/mm/sun3mmu.c b/arch/m68k/mm/sun3mmu.c
index 6a6513aa1c..edceefc188 100644
--- a/arch/m68k/mm/sun3mmu.c
+++ b/arch/m68k/mm/sun3mmu.c
@@ -53,7 +53,6 @@ void __init paging_init(void)
 	wp_works_ok = 0;
 #endif
 	empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
-	memset(empty_zero_page, 0, PAGE_SIZE);
 
 	address = PAGE_OFFSET;
 	pg_dir = swapper_pg_dir;