cvs commit: src/sys/amd64/amd64 exception.S trap.c src/sys/amd64/include frame.h signal.h ucontext.h

[Peter Wemm]

peter       2003/10/14 19:04:52 PDT

  FreeBSD src repository

  Modified files:
    sys/amd64/amd64      exception.S trap.c 
    sys/amd64/include    frame.h signal.h ucontext.h 
  Log:
  Pull the tier-2 card one last time and break the get/setcontext and
  sigreturn() ABI and the signal context on the stack.
  
  Make the trapframe (and its shadows in the ucontext and sigframe etc)
  8 bytes larger in order to preserve 16 byte stack alignment for the
  following C code calls.  I could have done some padding after the
  trapframe was saved, but some of the C code still expects an argument of
  'struct trapframe'.  Anyway, this gives me a spare field that can be used
  to store things like 'partial trapframe' status or something else in
  the future.
  
  The runtime impact is fairly small, *except* for threaded apps and things
  that decode contexts and the signal stack (eg: cvsup binary).  Signal
  delivery isn't too badly affected because the kernel generates the
  sigframe that sigreturn uses after the handler has been called.
  
  The size of mcontext_t and struct sigframe hasn't changed.  Only
  the last few fields (sc_eip etc) got moved a little and I eliminated
  a spare field.  mc_len/sc_len did change location though so the
  sanity checks there will still trap it.
  
  Revision  Changes    Path
  1.113     +1 -1      src/sys/amd64/amd64/exception.S
  1.266     +9 -0      src/sys/amd64/amd64/trap.c
  1.25      +3 -0      src/sys/amd64/include/frame.h
  1.24      +2 -2      src/sys/amd64/include/signal.h
  1.16      +2 -2      src/sys/amd64/include/ucontext.h