1. 09 Mar, 2008 3 commits
  2. 08 Mar, 2008 1 commit
    • Roland McGrath's avatar
      x86_64: make ptrace always sign-extend orig_ax to 64 bits · 84c6f604
      Roland McGrath authored
      This makes 64-bit ptrace calls setting the 64-bit orig_ax field for a
      32-bit task sign-extend the low 32 bits up to 64.  This matches what a
      64-bit debugger expects when tracing a 32-bit task.
      
      This follows on my "x86_64 ia32 syscall restart fix".  This didn't
      matter until that was fixed.
      
      The debugger ignores or zeros the high half of every register slot it
      sets (including the orig_rax pseudo-register) uniformly.  It expects
      that the setting of the low 32 bits always has the same meaning as a
      32-bit debugger setting those same 32 bits with native 32-bit
      facilities.
      
      This never arose before because the syscall restart check never
      matched any -ERESTART* values due to lack of sign extension.  Before
      that fix, even 32-bit ptrace setting orig_eax to -1 failed to trigger
      the restart check anyway.  So this was never noticed as a regression
      of 64-bit debuggers vs 32-bit debuggers on the same 64-bit kernel.
      Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
      [ Changed to just do the sign-extension unconditionally on x86-64,
        since orig_ax is always just a small integer and doesn't need
        the full 64-bit range ]
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      84c6f604
  3. 07 Mar, 2008 36 commits