• David Miller's avatar
    slab: Fix off by one in object max number tests. · 30321c7b
    David Miller authored
    If freelist_idx_t is a byte, SLAB_OBJ_MAX_NUM should be 255 not 256, and
    likewise if freelist_idx_t is a short, then it should be 65535 not
    65536.
    
    This was leading to all kinds of random crashes on sparc64 where
    PAGE_SIZE is 8192.  One problem shown was that if spinlock debugging was
    enabled, we'd get deadlocks in copy_pte_range() or do_wp_page() with the
    same cpu already holding a lock it shouldn't hold, or the lock belonging
    to a completely unrelated process.
    
    Fixes: a41adfaa ("slab: introduce byte sized index for the freelist of a slab")
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    30321c7b
slab.c 111 KB