Re: [Fwd: Re: gdb/725: Crash using debug target and regcaches (in 5.3 branch?)]

[Michael Snyder <msnyder@redhat.com>]

Daniel Jacobowitz wrote:
> 
> On Thu, Nov 21, 2002 at 09:37:24PM -0500, Daniel Jacobowitz wrote:
> > 2002-11-21  Daniel Jacobowitz  <drow@mvista.com>
> >
> >       Fix PR gdb/725
> >       * lin-lwp.c (lin_lwp_fetch_registers): Remove.
> >       (lin_lwp_store_registers): Remove.
> >       (init_lin_lwp_ops): Use fetch_inferior_registers
> >       and store_inferior_registers directly.
> >       * sparc-nat.c (fetch_inferior_registers): Honor LWP ID.
> >       (store_inferior_registers): Likewise.
> 
> Any comments on this patch?  If you like it, feel free to commit it for
> 5.3 - I'll be out of town this week.

Seems like the spirit is in the right place.
Mark is probably in a better position than I am to comment on
the implementation.

> 
> >
> > Index: lin-lwp.c
> > ===================================================================
> > RCS file: /cvs/src/src/gdb/lin-lwp.c,v
> > retrieving revision 1.36
> > diff -u -p -r1.36 lin-lwp.c
> > --- lin-lwp.c 31 Oct 2002 21:00:08 -0000      1.36
> > +++ lin-lwp.c 22 Nov 2002 02:35:31 -0000
> > @@ -1343,32 +1343,6 @@ lin_lwp_mourn_inferior (void)
> >    child_ops.to_mourn_inferior ();
> >  }
> >
> > -static void
> > -lin_lwp_fetch_registers (int regno)
> > -{
> > -  struct cleanup *old_chain = save_inferior_ptid ();
> > -
> > -  if (is_lwp (inferior_ptid))
> > -    inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid));
> > -
> > -  fetch_inferior_registers (regno);
> > -
> > -  do_cleanups (old_chain);
> > -}
> > -
> > -static void
> > -lin_lwp_store_registers (int regno)
> > -{
> > -  struct cleanup *old_chain = save_inferior_ptid ();
> > -
> > -  if (is_lwp (inferior_ptid))
> > -    inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid));
> > -
> > -  store_inferior_registers (regno);
> > -
> > -  do_cleanups (old_chain);
> > -}
> > -
> >  static int
> >  lin_lwp_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
> >                    struct mem_attrib *attrib,
> > @@ -1426,8 +1400,10 @@ init_lin_lwp_ops (void)
> >    lin_lwp_ops.to_detach = lin_lwp_detach;
> >    lin_lwp_ops.to_resume = lin_lwp_resume;
> >    lin_lwp_ops.to_wait = lin_lwp_wait;
> > -  lin_lwp_ops.to_fetch_registers = lin_lwp_fetch_registers;
> > -  lin_lwp_ops.to_store_registers = lin_lwp_store_registers;
> > +  /* fetch_inferior_registers and store_inferior_registers will
> > +     honor the LWP id, so we can use them directly.  */
> > +  lin_lwp_ops.to_fetch_registers = fetch_inferior_registers;
> > +  lin_lwp_ops.to_store_registers = store_inferior_registers;
> >    lin_lwp_ops.to_xfer_memory = lin_lwp_xfer_memory;
> >    lin_lwp_ops.to_kill = lin_lwp_kill;
> >    lin_lwp_ops.to_create_inferior = lin_lwp_create_inferior;
> > Index: sparc-nat.c
> > ===================================================================
> > RCS file: /cvs/src/src/gdb/sparc-nat.c,v
> > retrieving revision 1.15
> > diff -u -p -r1.15 sparc-nat.c
> > --- sparc-nat.c       14 Nov 2002 20:37:29 -0000      1.15
> > +++ sparc-nat.c       22 Nov 2002 02:35:31 -0000
> > @@ -1,5 +1,6 @@
> >  /* Functions specific to running gdb native on a SPARC running SunOS4.
> > -   Copyright 1989, 1992, 1993, 1994, 1996, 1997, 1998, 1999, 2000, 2001
> > +   Copyright 1989, 1992, 1993, 1994, 1996, 1997, 1998, 1999, 2000, 2001,
> > +   2002
> >     Free Software Foundation, Inc.
> >
> >     This file is part of GDB.
> > @@ -58,6 +59,11 @@ fetch_inferior_registers (int regno)
> >    struct regs inferior_registers;
> >    struct fp_status inferior_fp_registers;
> >    int i;
> > +  int fetch_pid;
> > +
> > +  fetch_pid = TIDGET (inferior_ptid);
> > +  if (fetch_pid == 0)
> > +    fetch_pid = PIDGET (inferior_ptid);
> >
> >    /* We should never be called with deferred stores, because a prerequisite
> >       for writing regs is to have fetched them all (PREPARE_TO_STORE), sigh.  */
> > @@ -75,7 +81,7 @@ fetch_inferior_registers (int regno)
> >        || regno >= Y_REGNUM
> >        || (!deprecated_register_valid[SP_REGNUM] && regno < I7_REGNUM))
> >      {
> > -      if (0 != ptrace (PTRACE_GETREGS, PIDGET (inferior_ptid),
> > +      if (0 != ptrace (PTRACE_GETREGS, fetch_pid,
> >                      (PTRACE_ARG3_TYPE) & inferior_registers, 0))
> >       perror ("ptrace_getregs");
> >
> > @@ -108,7 +114,7 @@ fetch_inferior_registers (int regno)
> >        regno == FPS_REGNUM ||
> >        (regno >= FP0_REGNUM && regno <= FP0_REGNUM + 31))
> >      {
> > -      if (0 != ptrace (PTRACE_GETFPREGS, PIDGET (inferior_ptid),
> > +      if (0 != ptrace (PTRACE_GETFPREGS, fetch_pid,
> >                      (PTRACE_ARG3_TYPE) & inferior_fp_registers,
> >                      0))
> >       perror ("ptrace_getfpregs");
> > @@ -153,6 +159,11 @@ store_inferior_registers (int regno)
> >    struct regs inferior_registers;
> >    struct fp_status inferior_fp_registers;
> >    int wanna_store = INT_REGS + STACK_REGS + FP_REGS;
> > +  int store_pid;
> > +
> > +  store_pid = TIDGET (inferior_ptid);
> > +  if (store_pid == 0)
> > +    store_pid = PIDGET (inferior_ptid);
> >
> >    /* First decide which pieces of machine-state we need to modify.
> >       Default for regno == -1 case is all pieces.  */
> > @@ -236,7 +247,7 @@ store_inferior_registers (int regno)
> >        inferior_registers.r_y =
> >       *(int *) &deprecated_registers[REGISTER_BYTE (Y_REGNUM)];
> >
> > -      if (0 != ptrace (PTRACE_SETREGS, PIDGET (inferior_ptid),
> > +      if (0 != ptrace (PTRACE_SETREGS, store_pid,
> >                      (PTRACE_ARG3_TYPE) & inferior_registers, 0))
> >       perror ("ptrace_setregs");
> >      }
> > @@ -252,7 +263,7 @@ store_inferior_registers (int regno)
> >             &deprecated_registers[REGISTER_BYTE (FPS_REGNUM)],
> >             sizeof (FPU_FSR_TYPE));
> >        if (0 !=
> > -       ptrace (PTRACE_SETFPREGS, PIDGET (inferior_ptid),
> > +       ptrace (PTRACE_SETFPREGS, store_pid,
> >                 (PTRACE_ARG3_TYPE) & inferior_fp_registers, 0))
> >       perror ("ptrace_setfpregs");
> >      }
> >
> 
> --
> Daniel Jacobowitz
> MontaVista Software                         Debian GNU/Linux Developer