Re: [PATCH 02/15] Remove some GDBSERVER checks from linux-ptrace

[Doug Evans <dje at google dot com>]

Gary Benson writes:
 > This patch removes some GDBSERVER checks from nat/linux-ptrace.c.
 > Currently the code uses a compile-time check to decide whether some
 > flags should be used.  This changes the code to instead let users of
 > the module specify an additional set of flags; and then changes gdb's
 > linux-nat.c to call this function.  At some later date, when the back
 > ends are fully merged, we will be able to remove this function again.
 > 
 > gdb/
 > 2014-07-09  Tom Tromey  <tromey@redhat.com>
 > 	    Gary Benson  <gbenson@redhat.com>
 > 
 > 	* nat/linux-ptrace.c (additional_flags): New global.
 > 	(linux_test_for_tracesysgood, linux_test_for_tracefork): Use
 > 	additional_flags; don't check GDBSERVER.
 > 	(linux_ptrace_set_additional_flags): New function.
 > 	* nat/linux-ptrace.h (linux_ptrace_set_additional_flags):
 > 	Declare.
 > 	* linux-nat.c (_initialize_linux_nat): Call
 > 	linux_ptrace_set_additional_flags.

Hi.  Recognizing that this is a temporary hack, the patch is ok with me.
One nit below.

 > @@ -433,18 +435,7 @@ linux_test_for_tracefork (int child_pid)
 >  
 >  	  /* We got the PID from the grandchild, which means fork
 >  	     tracing is supported.  */
 > -#ifdef GDBSERVER
 > -	  /* Do not enable all the options for now since gdbserver does not
 > -	     properly support them.  This restriction will be lifted when
 > -	     gdbserver is augmented to support them.  */
 > -	  current_ptrace_options |= PTRACE_O_TRACECLONE;
 > -#else
 > -	  current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK
 > -	    | PTRACE_O_TRACECLONE | PTRACE_O_TRACEEXEC;
 > -
 > -	  /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to
 > -	     support read-only process state.  */
 > -#endif
 > +	  current_ptrace_options |= PTRACE_O_TRACECLONE | additional_flags;
 >  
 >  	  /* Do some cleanup and kill the grandchild.  */
 >  	  my_waitpid (second_pid, &second_status, 0);

I can't tell if the PTRACE_O_TRACEEXIT comment was accidentally
or intentionally dropped.
I'm not sure it's important enough to keep, but it would be
good to verify its deletion was intentional.