1. 06 May, 2014 2 commits
    • 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
    • Joonsoo Kim's avatar
      slab: fix the type of the index on freelist index accessor · 7cc68973
      Joonsoo Kim authored
      Commit a41adfaa ("slab: introduce byte sized index for the freelist
      of a slab") changes the size of freelist index and also changes
      prototype of accessor function to freelist index.  And there was a
      mistake.
      
      The mistake is that although it changes the size of freelist index
      correctly, it changes the size of the index of freelist index
      incorrectly.  With patch, freelist index can be 1 byte or 2 bytes, that
      means that num of object on on a slab can be more than 255.  So we need
      more than 1 byte for the index to find the index of free object on
      freelist.  But, above patch makes this index type 1 byte, so slab which
      have more than 255 objects cannot work properly and in consequence of
      it, the system cannot boot.
      
      This issue was reported by Steven King on m68knommu which would use
      2 bytes freelist index:
      
        https://lkml.org/lkml/2014/4/16/433
      
      To fix is easy.  To change the type of the index of freelist index on
      accessor functions is enough to fix this bug.  Although 2 bytes is
      enough, I use 4 bytes since it have no bad effect and make things more
      easier.  This fix was suggested and tested by Steven in his original
      report.
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Reported-and-acked-by: default avatarSteven King <sfking@fdwdc.com>
      Acked-by: default avatarChristoph Lameter <cl@linux.com>
      Tested-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Tested-by: default avatarDavid Miller <davem@davemloft.net>
      Cc: Pekka Enberg <penberg@kernel.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7cc68973
  2. 05 May, 2014 36 commits
  3. 04 May, 2014 2 commits