Commit 6ce1b871 authored by Julia Lawall's avatar Julia Lawall Committed by Russell King

[ARM] eliminate NULL test and memset after alloc_bootmem

As noted by Akinobu Mita in patch b1fceac2,
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: default avatarJulia Lawall <julia@diku.dk>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent d517cab1
...@@ -827,7 +827,6 @@ static void __init devicemaps_init(struct machine_desc *mdesc) ...@@ -827,7 +827,6 @@ static void __init devicemaps_init(struct machine_desc *mdesc)
* Allocate the vector page early. * Allocate the vector page early.
*/ */
vectors = alloc_bootmem_low_pages(PAGE_SIZE); vectors = alloc_bootmem_low_pages(PAGE_SIZE);
BUG_ON(!vectors);
for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE) for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE)
pmd_clear(pmd_off_k(addr)); pmd_clear(pmd_off_k(addr));
...@@ -912,10 +911,10 @@ void __init paging_init(struct machine_desc *mdesc) ...@@ -912,10 +911,10 @@ void __init paging_init(struct machine_desc *mdesc)
top_pmd = pmd_off_k(0xffff0000); top_pmd = pmd_off_k(0xffff0000);
/* /*
* allocate the zero page. Note that we count on this going ok. * allocate the zero page. Note that this always succeeds and
* returns a zeroed result.
*/ */
zero_page = alloc_bootmem_low_pages(PAGE_SIZE); zero_page = alloc_bootmem_low_pages(PAGE_SIZE);
memset(zero_page, 0, PAGE_SIZE);
empty_zero_page = virt_to_page(zero_page); empty_zero_page = virt_to_page(zero_page);
flush_dcache_page(empty_zero_page); flush_dcache_page(empty_zero_page);
} }
......
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