1. 28 May, 2013 1 commit
  2. 21 May, 2013 1 commit
    • Mikael Pettersson's avatar
      m68k: implement futex.h to support userspace robust futexes and PI mutexes · e4f2dfbb
      Mikael Pettersson authored
      Linux/M68K currently doesn't support robust futexes or PI mutexes.
      The problem is that the futex code needs to perform certain ops
      (cmpxchg, set, add, or, andn, xor) atomically on user-space
      addresses, and M68K's lack of a futex.h causes those operations
      to be unsupported and disabled.
      
      This patch adds that support, but only for uniprocessor machines,
      which is adequate for M68K.  For UP it's enough to disable preemption
      to ensure mutual exclusion (futexes don't need to care about other
      hardware agents), and the mandatory pagefault_disable() does just that.
      
      This patch is closely based on the one I co-wrote for UP ARM back
      in August 2008.  The main change is that this patch uses the C
      get_user/put_user accessors instead of inline assembly code with
      exception table fixups.
      
      For non-MMU machines the new futex.h simply redirects to the generic
      futex.h, so there is no functional change for them.
      
      Tested on aranym with the glibc-2.17 test suite: no regressions, and
      a number of mutex/condvar test cases went from failing to succeeding
      (tst-mutexpi{5,5a,6,9}, tst-cond2[45], tst-robust[1-9], tst-robustpi[1-8]).
      Also tested with glibc-2.18 HEAD and a local glibc patch to enable PI
      mutexes: no regressions.
      Signed-off-by: default avatarMikael Pettersson <mikpe@it.uu.se>
      Acked-by: default avatarAndreas Schwab <schwab@linux-m68k.org>
      [geert: Added removal of ""generic-y += futex.h"]
      Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
      e4f2dfbb
  3. 20 May, 2013 10 commits
  4. 19 May, 2013 3 commits
  5. 18 May, 2013 25 commits