Re: [RFA] Resubmit process record and replay, 7/10

[Michael Snyder <msnyder@vmware.com>]

teawater wrote:
> This patch add code to make GNU/Linux native-dependent code can record
> execute log with itself.
> 
> 2008-11-16  Hui Zhu  <teawater@gmail.com>
> 
> 	Record execute log in linux-nat.
> 
> 	* linux-nat.c (my_waitpid_record): New function. This function
> 	can resume and wait inferior and record execute log of it.
> 	(linux_nat_wait): If process record and replay target is used
> 	and this is not a step resume, call function
> 	"my_waitpid_record" instead function "my_waitpid".

Hui, another name change suggestion:
Instead of "my_waitpid_record", how about "process_record_waitpid"?

I don't think it needs to have "linux" in the name, since it is
a static function and can only be invoked from linux-nat.c.

> 
>  linux-nat.c |  122 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 121 insertions(+), 1 deletion(-)
> 
> 
> ------------------------------------------------------------------------
> 
> --- a/linux-nat.c
> +++ b/linux-nat.c
> @@ -50,6 +50,8 @@
>  #include "event-loop.h"
>  #include "event-top.h"
>  
> +#include "record.h"
> +
>  #ifdef HAVE_PERSONALITY
>  # include <sys/personality.h>
>  # if !HAVE_DECL_ADDR_NO_RANDOMIZE
> @@ -518,6 +520,115 @@ my_waitpid (int pid, int *status, int fl
>    return ret;
>  }
>  
> +extern struct bp_location *bp_location_chain;
> +static struct lwp_info * find_lwp_pid (ptid_t ptid);
> +static int
> +my_waitpid_record (int pid, int *status, int flags)
> +{
> +  int ret;
> +  struct bp_location *bl;
> +  struct breakpoint *b;
> +  CORE_ADDR pc;
> +  CORE_ADDR decr_pc_after_break;
> +  struct lwp_info *lp;
> +  int is_breakpoint = 1;
> +
> +wait_begin:
> +  ret = my_waitpid (pid, status, flags);
> +  if (ret == -1)
> +    {
> +      return ret;
> +    }
> +
> +  if (ret == 0)
> +    {
> +      goto wait_begin;
> +    }
> +
> +  if (WIFSTOPPED (*status) && WSTOPSIG (*status) == SIGTRAP)
> +    {
> +      /* Check if there is a breakpoint.  */
> +      pc = 0;
> +      registers_changed ();
> +      for (bl = bp_location_chain; bl; bl = bl->global_next)
> +	{
> +	  b = bl->owner;
> +	  gdb_assert (b);
> +	  if (b->enable_state != bp_enabled
> +	      && b->enable_state != bp_permanent)
> +	    continue;
> +	  if (!pc)
> +	    {
> +	      pc = regcache_read_pc (get_thread_regcache (pid_to_ptid (ret)));
> +	    }
> +	  switch (b->type)
> +	    {
> +	    default:
> +	      if (bl->address == pc)
> +		{
> +		  goto out;
> +		}
> +	      break;
> +
> +	    case bp_watchpoint:
> +	      /*XXX teawater: I still not very clear how to deal with it.  */
> +	      goto out;
> +	      break;
> +
> +	    case bp_catchpoint:
> +	      gdb_assert (b->ops != NULL && b->ops->breakpoint_hit != NULL);
> +	      if (b->ops->breakpoint_hit (b))
> +		{
> +		  goto out;
> +		}
> +	      break;
> +
> +	    case bp_hardware_watchpoint:
> +	    case bp_read_watchpoint:
> +	    case bp_access_watchpoint:
> +	      if (STOPPED_BY_WATCHPOINT (0))
> +		{
> +		  goto out;
> +		}
> +	      break;
> +	    }
> +	}
> +
> +      lp = find_lwp_pid (pid_to_ptid (ret));
> +      if (lp)
> +        lp->stopped = 1;
> +
> +      /* record message */
> +      record_message (current_gdbarch);
> +
> +      /* resume program */
> +      linux_ops->to_resume (pid_to_ptid (ret), 1, TARGET_SIGNAL_0);
> +      goto wait_begin;
> +    }
> +
> +  is_breakpoint = 0;
> +
> +out:
> +  /* Add gdbarch_decr_pc_after_break to pc because pc will be break at address
> +     add gdbarch_decr_pc_after_break when inferior non-step execute.  */
> +  if (is_breakpoint)
> +    {
> +      decr_pc_after_break = gdbarch_decr_pc_after_break
> +	(get_regcache_arch (get_thread_regcache (pid_to_ptid (ret))));
> +      if (decr_pc_after_break)
> +	{
> +	  if (!pc)
> +	    {
> +	      pc = regcache_read_pc (get_thread_regcache (pid_to_ptid (ret)));
> +	    }
> +	  regcache_write_pc (get_thread_regcache (pid_to_ptid (ret)),
> +			     pc + decr_pc_after_break);
> +	}
> +    }
> +
> +  return ret;
> +}
> +
>  /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
>  
>     First, we try to enable fork tracing on ORIGINAL_PID.  If this fails,
> @@ -2876,7 +2987,16 @@ retry:
>  	   queued events.  */
>  	lwpid = queued_waitpid (pid, &status, options);
>        else
> -	lwpid = my_waitpid (pid, &status, options);
> +	{
> +	  if (RECORD_IS_USED && !record_resume_step)
> +	    {
> +	      lwpid = my_waitpid_record (pid, &status, options);
> +	    }
> +	  else
> +	    {
> +	      lwpid = my_waitpid (pid, &status, options);
> +	    }
> +	}
>  
>        if (lwpid > 0)
>  	{