1. 26 9月, 2011 17 次提交
  2. 21 9月, 2011 2 次提交
  3. 20 9月, 2011 2 次提交
  4. 16 9月, 2011 1 次提交
    • L
      asm alternatives: remove incorrect alignment notes · a7f934d4
      Linus Torvalds 提交于
      On x86-64, they were just wasteful: with the explicitly added (now
      unnecessary) padding, the size of the alternatives structure was 16
      bytes, and an alignment of 8 bytes didn't hurt much.
      
      However, it was still silly, since the natural size and alignment for
      the structure is actually just 12 bytes, 4-byte aligned since commit
      59e97e4d ("x86: Make alternative instruction pointers relative").
      So removing the padding, and removing the extra alignment is just a good
      idea.
      
      On x86-32, the alignment of 4 bytes was correct, but was incorrectly
      hardcoded as 8 bytes in <asm/alternative-asm.h>.  That header file had
      used to be an x86-64 only header file, but various unification efforts
      have made it be used for x86-32 too (ie the unification of rwlock and
      rwsem).
      
      That in turn caused x86-32 boot failures, because the extra alignment
      would result in random zero-filled words in the altinstructions section,
      causing oopses early at boot when doing alternative instruction
      replacement.
      
      So just remove all the alignment noise entirely.  It's wrong, and it's
      unnecessary.  The section itself is already properly aligned by the
      linker scripts, and all additions to the section had better be of the
      proper 12-byte format, keeping it aligned.  So if the align directive
      were to ever make a difference, that would be an indication of a serious
      bug to begin with.
      Reported-by: NWerner Landgraf <w.landgraf@ru.r>
      Acked-by: NAndrew Lutomirski <luto@mit.edu>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a7f934d4
  5. 15 9月, 2011 18 次提交