1. 27 Feb, 2012 2 commits
    • Linus Torvalds's avatar
      i387: make irq_fpu_usable() tests more robust · 42f2560e
      Linus Torvalds authored
      commit 5b1cbac3 upstream.
      
      Some code - especially the crypto layer - wants to use the x86
      FP/MMX/AVX register set in what may be interrupt (typically softirq)
      context.
      
      That *can* be ok, but the tests for when it was ok were somewhat
      suspect.  We cannot touch the thread-specific status bits either, so
      we'd better check that we're not going to try to save FP state or
      anything like that.
      
      Now, it may be that the TS bit is always cleared *before* we set the
      USEDFPU bit (and only set when we had already cleared the USEDFP
      before), so the TS bit test may actually have been sufficient, but it
      certainly was not obviously so.
      
      So this explicitly verifies that we will not touch the TS_USEDFPU bit,
      and adds a few related sanity-checks.  Because it seems that somehow
      AES-NI is corrupting user FP state.  The cause is not clear, and this
      patch doesn't fix it, but while debugging it I really wanted the code to
      be more obviously correct and robust.
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      42f2560e
    • Linus Torvalds's avatar
      i387: math_state_restore() isn't called from asm · 4733009d
      Linus Torvalds authored
      commit be98c2cd upstream.
      
      It was marked asmlinkage for some really old and stale legacy reasons.
      Fix that and the equally stale comment.
      
      Noticed when debugging the irq_fpu_usable() bugs.
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4733009d
  2. 20 Feb, 2012 30 commits
  3. 13 Feb, 2012 8 commits