• Julia Lawall's avatar
    [ARM] eliminate NULL test and memset after alloc_bootmem · 6ce1b871
    Julia Lawall authored
    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>
    6ce1b871
mmu.c 25.2 KB