1. 24 Jun, 2005 5 commits
    • David Howells's avatar
      [PATCH] keys: Discard key spinlock and use RCU for key payload · 76d8aeab
      David Howells authored
      The attached patch changes the key implementation in a number of ways:
      
       (1) It removes the spinlock from the key structure.
      
       (2) The key flags are now accessed using atomic bitops instead of
           write-locking the key spinlock and using C bitwise operators.
      
           The three instantiation flags are dealt with with the construction
           semaphore held during the request_key/instantiate/negate sequence, thus
           rendering the spinlock superfluous.
      
           The key flags are also now bit numbers not bit masks.
      
       (3) The key payload is now accessed using RCU. This permits the recursive
           keyring search algorithm to be simplified greatly since no locks need be
           taken other than the usual RCU preemption disablement. Searching now does
           not require any locks or semaphores to be held; merely that the starting
           keyring be pinned.
      
       (4) The keyring payload now includes an RCU head so that it can be disposed
           of by call_rcu(). This requires that the payload be copied on unlink to
           prevent introducing races in copy-down vs search-up.
      
       (5) The user key payload is now a structure with the data following it. It
           includes an RCU head like the keyring payload and for the same reason. It
           also contains a data length because the data length in the key may be
           changed on another CPU whilst an RCU protected read is in progress on the
           payload. This would then see the supposed RCU payload and the on-key data
           length getting out of sync.
      
           I'm tempted to drop the key's datalen entirely, except that it's used in
           conjunction with quota management and so is a little tricky to get rid
           of.
      
       (6) Update the keys documentation.
      Signed-Off-By: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      76d8aeab
    • Andrea Arcangeli's avatar
      [PATCH] ppc64: fix seccomp with 32-bit userland · 7286aa9b
      Andrea Arcangeli authored
      The seccomp check has to happen when entering the syscall and not when
      exiting it or regs->gpr[0] contains garabge during signal handling in
      ppc64_rt_sigreturn (this actually might be a bug too, but an orthogonal
      one, since we really have to run the check before invoking the syscall and
      not after it).
      Signed-off-by: default avatarAndrea Arcangeli <andrea@cpushare.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      7286aa9b
    • Linus Torvalds's avatar
    • Linus Torvalds's avatar
    • Linus Torvalds's avatar
      adb7ee37
  2. 23 Jun, 2005 35 commits