[ARM] eliminate NULL test and memset after alloc_bootmem
authorJulia Lawall <julia@diku.dk>
Mon, 1 Dec 2008 22:15:41 +0000 (14:15 -0800)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Sun, 14 Dec 2008 12:05:03 +0000 (12:05 +0000)
commit6ce1b871db6a3ca69ed1e35956d89d3cacd7ba08
treefa3a1d73cc601de707ec21dad485319d42f7bfb5
parentd517cab1c7fc92178e11c7ded2548b06b273d293
[ARM] 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 = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\|alloc_bootmem_node\|alloc_bootmem_low_pages_node\|alloc_bootmem_pages_node\)(...)
... when != E
(
- BUG_ON (E == NULL);
|
- if (E == NULL) S
)

@@
expression E,E1;
@@

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

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/mm/mmu.c