1. 23 Oct, 2008 1 commit
  2. 13 Oct, 2008 1 commit
  3. 22 Jul, 2008 1 commit
    • Vegard Nossum's avatar
      x86: consolidate header guards · 77ef50a5
      Vegard Nossum authored
      
      
      This patch is the result of an automatic script that consolidates the
      format of all the headers in include/asm-x86/.
      
      The format:
      
      1. No leading underscore. Names with leading underscores are reserved.
      2. Pathname components are separated by two underscores. So we can
         distinguish between mm_types.h and mm/types.h.
      3. Everything except letters and numbers are turned into single
         underscores.
      Signed-off-by: default avatarVegard Nossum <vegard.nossum@gmail.com>
      77ef50a5
  4. 11 Jul, 2008 1 commit
    • Ingo Molnar's avatar
      x86: fix savesegment() bug causing crashes on 64-bit · d9fc3fd3
      Ingo Molnar authored
      
      
      i spent a fair amount of time chasing a 64-bit bootup crash that manifested
      itself as bootup segfaults:
      
        S10network[1825]: segfault at 7f3e2b5d16b8 ip 00000031108748c9 sp 00007fffb9c14c70 error 4 in libc-2.7.so[3110800000+14d000]
      
      eventually causing init to die and panic the system:
      
        Kernel panic - not syncing: Attempted to kill init!
        Pid: 1, comm: init Not tainted 2.6.26-rc9-tip #13878
      
      after a maratonic bisection session, the bad commit turned out to be:
      
      | b7675791859075418199c7af86a116ea34eaf5bd is first bad commit
      | commit b7675791859075418199c7af86a116ea34eaf5bd
      | Author: Jeremy Fitzhardinge <jeremy@goop.org>
      | Date:   Wed Jun 25 00:19:00 2008 -0400
      |
      |     x86: remove open-coded save/load segment operations
      |
      |     This removes a pile of buggy open-coded implementations of savesegment
      |     and loadsegment.
      
      after some more bisection of this patch itself, it turns out that what
      makes the difference are the savesegment() changes to __switch_to().
      
      Taking a look at this portion of arch/x86/kernel/process_64.o revealed
      this crutial difference:
      
      | good:    99c:       8c e0                   mov    %fs,%eax
      |          99e:       89 45 cc                mov    %eax,-0x34(%rbp)
      |
      | bad:     99c:       8c 65 cc                mov    %fs,-0x34(%rbp)
      
      which is due to:
      
      |                 unsigned fsindex;
      | -               asm volatile("movl %%fs,%0" : "=r" (fsindex));
      | +               savesegment(fs, fsindex);
      
      savesegment() is implemented as:
      
       #define savesegment(seg, value)                                \
                asm("mov %%" #seg ",%0":"=rm" (value) : : "memory")
      
      note the "m" modifier - it allows GCC to generate the segment move
      into a memory operand as well.
      
      But regarding segment operands there's a subtle detail in the x86
      instruction set: the above 16-bit moves are zero-extend, but only
      if it goes to a register.
      
      If it goes to a memory operand, -0x34(%rbp) in the above case, there's
      no zero-extend to 32-bit and the instruction will only save 16 bits
      instead of the intended 32-bit.
      
      The other 16 bits is random data - which can cause problems when that
      value is used later on.
      
      The solution is to only allow segment operands to go to registers.
      This fix allows my test-system to boot up without crashing.
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      d9fc3fd3
  5. 08 Jul, 2008 2 commits
  6. 27 May, 2008 1 commit
  7. 25 May, 2008 1 commit
  8. 17 Apr, 2008 4 commits
  9. 04 Feb, 2008 3 commits
  10. 30 Jan, 2008 9 commits
  11. 11 Oct, 2007 1 commit