Re: [patch 7/8] Agent capability for static tracepoint

[Pedro Alves <palves@redhat.com>]

On 01/23/2012 02:07 PM, Yao Qi wrote:
> Current libinproctrace.so agent is able to do operations on static
> tracepoint, which can be treated as one capability.  This patch is to
> teach gdbserver to check agent's capability when performing operations
> related to static tracepoint.
> 

Hmm, not sure.  Why aren't these being hooked at the same places
where we already check/call maybe_write_ipa_ust_not_loaded and
in_process_agent_loaded_ust?

> -- Yao (齐尧)
> 
> 
> 0007-gdb-agent-for-static-tracepoint.patch
> 
> 
> 2012-01-23  Yao Qi  <yao@codesourcery.com>
> 
> 	* tracepoint.c (gdb_agent_capability): New global.
> 	(clear_installed_tracepoints): Check whether agent has capability
> 	for static tracepoint.
> 	(install_tracepoint): Likewise.
> 	(cmd_qtstart): Likewise.
> 	(handle_tracepoint_query): Likewise.
> ---
>  gdb/gdbserver/tracepoint.c |   68 +++++++++++++++++++++++++++++--------------
>  1 files changed, 46 insertions(+), 22 deletions(-)
> 
> diff --git a/gdb/gdbserver/tracepoint.c b/gdb/gdbserver/tracepoint.c
> index 7f462bc..9527d74 100644
> --- a/gdb/gdbserver/tracepoint.c
> +++ b/gdb/gdbserver/tracepoint.c
> @@ -2314,7 +2314,11 @@ clear_installed_tracepoints (void)
>  	    ;
>  	  else
>  	    {
> -	      unprobe_marker_at (tpoint->address);
> +	      if (agent_check_capability (AGENT_CAPA_STATIC_TRACE) == 0)
> +		warning ("Agent does not have capability"
> +			 "for static tracepoint.");
> +	      else
> +		unprobe_marker_at (tpoint->address);
>  	      prev_stpoint = tpoint;
>  	    }
>  	  break;
> @@ -2989,8 +2993,8 @@ install_tracepoint (struct tracepoint *tpoint, char *own_buf)
>  	}
>        else
>  	{
> -	  if (tp)
> -	    tpoint->handle = (void *) -1;
> +	  if (agent_check_capability (AGENT_CAPA_STATIC_TRACE) == 0)
> +	    warning ("Agent does not have capability for static tracepoint.");
>  	  else
>  	    {
>  	      if (probe_marker_at (tpoint->address, own_buf) == 0)
> @@ -3094,13 +3098,19 @@ cmd_qtstart (char *packet)
>  	    }
>  	  else
>  	    {
> -	      if (probe_marker_at (tpoint->address, packet) == 0)
> +	      if (agent_check_capability (AGENT_CAPA_STATIC_TRACE) == 0)
> +		warning ("Agent does not have capability"
> +			 "for static tracepoint.");
> +	      else
>  		{
> -		  tpoint->handle = (void *) -1;
> -
> -		  /* So that we can handle multiple static tracepoints
> -		     at the same address easily.  */
> -		  prev_stpoint = tpoint;
> +		  if (probe_marker_at (tpoint->address, packet) == 0)
> +		    {
> +		      tpoint->handle = (void *) -1;
> +
> +		      /* So that we can handle multiple static tracepoints
> +			 at the same address easily.  */
> +		      prev_stpoint = tpoint;
> +		    }
>  		}
>  	    }
>  	}
> @@ -3968,20 +3978,32 @@ handle_tracepoint_query (char *packet)
>        cmd_qtbuffer (packet);
>        return 1;
>      }
> -  else if (strcmp ("qTfSTM", packet) == 0)
> -    {
> -      cmd_qtfstm (packet);
> -      return 1;
> -    }
> -  else if (strcmp ("qTsSTM", packet) == 0)
> +  else if (strcmp ("qTfSTM", packet) == 0 || strcmp ("qTsSTM", packet) == 0
> +	   || strncmp ("qTSTMat:", packet, strlen ("qTSTMat:")) == 0)
>      {
> -      cmd_qtsstm (packet);
> -      return 1;
> -    }
> -  else if (strncmp ("qTSTMat:", packet, strlen ("qTSTMat:")) == 0)
> -    {
> -      cmd_qtstmat (packet);
> -      return 1;
> +      if (agent_check_capability (AGENT_CAPA_STATIC_TRACE) == 0)
> +	{
> +	  warning ("Agent does not have capability for static tracepoint.");
> +	  return 0;
> +	}
> +      else
> +	{
> +	  if (strcmp ("qTfSTM", packet) == 0)
> +	    {
> +	      cmd_qtfstm (packet);
> +	      return 1;
> +	    }
> +	  else if (strcmp ("qTsSTM", packet) == 0)
> +	    {
> +	      cmd_qtsstm (packet);
> +	      return 1;
> +	    }
> +	  else if (strncmp ("qTSTMat:", packet, strlen ("qTSTMat:")) == 0)
> +	    {
> +	      cmd_qtstmat (packet);
> +	      return 1;
> +	    }
> +	}
>      }
>    else if (strcmp ("qTMinFTPILen", packet) == 0)
>      {
> @@ -7986,6 +8008,8 @@ gdb_ust_thread (void *arg)
>  
>  #include <signal.h>
>  
> +IP_AGENT_EXPORT int gdb_agent_capability = AGENT_CAPA_STATIC_TRACE;
> +
>  static void
>  gdb_ust_init (void)
>  {
> -- 1.7.0.4


-- 
Pedro Alves