[PATCH 9/14] arch/sparc64: Eliminate NULL test and memset afteralloc_bootmem

From: Julia Lawall
Date: Tue Jun 24 2008 - 04:25:26 EST


From: Julia Lawall <julia@xxxxxxx>

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.

arch/sparc64/kernel/irq.c | 8 --------
1 file changed, 8 deletions(-)

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@xxxxxxx>
---

diff -u -p a/arch/sparc64/kernel/irq.c b/arch/sparc64/kernel/irq.c
--- a/arch/sparc64/kernel/irq.c
+++ b/arch/sparc64/kernel/irq.c
@@ -882,10 +882,6 @@ static void __init init_cpu_send_mondo_i
BUILD_BUG_ON((NR_CPUS * sizeof(u16)) > (PAGE_SIZE - 64));

page = alloc_bootmem_pages(PAGE_SIZE);
- if (!page) {
- prom_printf("SUN4V: Error, cannot allocate cpu mondo page.\n");
- prom_halt();
- }

tb->cpu_mondo_block_pa = __pa(page);
tb->cpu_list_pa = __pa(page + 64);
@@ -929,10 +925,6 @@ void __init init_IRQ(void)

size = sizeof(struct ino_bucket) * NUM_IVECS;
ivector_table = alloc_bootmem(size);
- if (!ivector_table) {
- prom_printf("Fatal error, cannot allocate ivector_table\n");
- prom_halt();
- }
__flush_dcache_range((unsigned long) ivector_table,
((unsigned long) ivector_table) + size);

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