1. 20 Mar, 2006 1 commit
  2. 03 Feb, 2006 1 commit
  3. 10 Jan, 2006 1 commit
  4. 12 Dec, 2005 1 commit
  5. 07 Nov, 2005 1 commit
  6. 17 Oct, 2005 1 commit
    • Herbert Xu's avatar
      [PATCH] list: add missing rcu_dereference on first element · b24d18aa
      Herbert Xu authored
      
      
      It seems that all the list_*_rcu primitives are missing a memory barrier
      on the very first dereference.  For example,
      
      #define list_for_each_rcu(pos, head) \
      	for (pos = (head)->next; prefetch(pos->next), pos != (head); \
      		pos = rcu_dereference(pos->next))
      
      It will go something like:
      
      	pos = (head)->next
      
      	prefetch(pos->next)
      
      	pos != (head)
      
      	do stuff
      
      We're missing a barrier here.
      
      	pos = rcu_dereference(pos->next)
      
      		fetch pos->next
      
      		barrier given by rcu_dereference(pos->next)
      
      		store pos
      
      Without the missing barrier, the pos->next value may turn out to be stale.
      In fact, if "do stuff" were also dereferencing pos and relying on
      list_for_each_rcu to provide the barrier then it may also break.
      
      So here is a patch to make sure that we have a barrier for the first
      element in the list.
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Acked-by: default avatar"Paul E. McKenney" <paulmck@us.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      b24d18aa
  7. 29 Aug, 2005 4 commits
  8. 25 Jun, 2005 1 commit
    • Paul E. McKenney's avatar
      [PATCH] RCU: clean up a few remaining synchronize_kernel() calls · b2b18660
      Paul E. McKenney authored
      
      
      2.6.12-rc6-mm1 has a few remaining synchronize_kernel()s, some (but not
      all) in comments.  This patch changes these synchronize_kernel() calls (and
      comments) to synchronize_rcu() or synchronize_sched() as follows:
      
      - arch/x86_64/kernel/mce.c mce_read(): change to synchronize_sched() to
        handle races with machine-check exceptions (synchronize_rcu() would not cut
        it given RCU implementations intended for hardcore realtime use.
      
      - drivers/input/serio/i8042.c i8042_stop(): change to synchronize_sched() to
        handle races with i8042_interrupt() interrupt handler.  Again,
        synchronize_rcu() would not cut it given RCU implementations intended for
        hardcore realtime use.
      
      - include/*/kdebug.h comments: change to synchronize_sched() to handle races
        with NMIs.  As before, synchronize_rcu() would not cut it...
      
      - include/linux/list.h comment: change to synchronize_rcu(), since this
        comment is for list_del_rcu().
      
      - security/keys/key.c unregister_key_type(): change to synchronize_rcu(),
        since this is interacting with RCU read side.
      
      - security/keys/process_keys.c install_session_keyring(): change to
        synchronize_rcu(), since this is interacting with RCU read side.
      Signed-off-by: default avatar"Paul E. McKenney" <paulmck@us.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      b2b18660
  9. 16 Apr, 2005 2 commits