gdb bug report

[David J. Roberts]

There are a couple bugs with the Solaris port of gdb in the area of
signal handling.  

   )  gdb is mapping several different SIGNALS to SIGSEGV.  Instead of
      reporting the real error type.  Like SIGBUS and SIGILL.
   )  gdb is not properly setting up arguments for a registered signal
      handler.

I have been playing around a CVS checked out version of the code
(gdb-5.3).  The latest update was 12/18/02.  The configuration is for
sparc-sun-solaris2.8.

Below is the output from "cvs idff -c" on src/gdb/procfs.c
which shows the changes needed to fix the above mentioned bugs.

   --David Roberts


Index: procfs.c
===================================================================
RCS file: /cvs/src/src/gdb/procfs.c,v
retrieving revision 1.41
diff -c -r1.41 procfs.c
*** procfs.c    11 Sep 2002 00:13:58 -0000      1.41
--- procfs.c    19 Dec 2002 02:14:56 -0000
***************
*** 42,47 ****
--- 42,48 ----
  #include <sys/wait.h>
  #include <signal.h>
  #include <ctype.h>
+ #include <assert.h>
  
  /* 
   * PROCFS.C
***************
*** 669,675 ****
  static procinfo *
  create_procinfo (int pid, int tid)
  {
!   procinfo *pi, *parent;
  
    if ((pi = find_procinfo (pid, tid)))
      return pi;                        /* Already exists, nothing to do. */
--- 670,676 ----
  static procinfo *
  create_procinfo (int pid, int tid)
  {
!   procinfo *pi, *parent = NULL;
  
    if ((pi = find_procinfo (pid, tid)))
      return pi;                        /* Already exists, nothing to do. */
***************
*** 1339,1344 ****
--- 1340,1380 ----
  }
  
  /*
+  * Function: proc_cursig:
+  *
+  * returns the pr_cursig field (current signal).
+  */
+ 
+ 
+ int
+ proc_curilltrapno (struct procinfo *pi)
+ {
+   if (!pi->status_valid)
+     if (!proc_get_status (pi))
+       return 0;       /* FIXME: not a good failure value (but what is?) */
+ 
+ #ifdef NEW_PROC_API
+   return pi->prstatus.pr_lwp.pr_info.si_trapno;
+ #else
+   assert(0);
+ #endif
+ }
+ 
+ void *
+ proc_curilladdr (struct procinfo *pi)
+ {
+   if (!pi->status_valid)
+     if (!proc_get_status (pi))
+       return 0;       /* FIXME: not a good failure value (but what is?) */
+ 
+ #ifdef NEW_PROC_API
+   return pi->prstatus.pr_lwp.pr_info.si_addr;
+ #else
+   assert(0);
+ #endif
+ }
+ 
+ /*
   * Function: proc_modify_flag 
   *
   *  === I appologize for the messiness of this function. 
***************
*** 2497,2505 ****
    mysinfo = (gdb_siginfo_t *) &arg.sinfo;
    mysinfo->si_signo = signo;
    mysinfo->si_code  = 0;
    mysinfo->si_pid   = getpid ();       /* ?why? */
    mysinfo->si_uid   = getuid ();       /* ?why? */
! 
  #ifdef NEW_PROC_API
    arg.cmd = PCSSIG;
    win = (write (pi->ctl_fd, (void *) &arg, sizeof (arg))  == sizeof (arg));
--- 2533,2560 ----
    mysinfo = (gdb_siginfo_t *) &arg.sinfo;
    mysinfo->si_signo = signo;
    mysinfo->si_code  = 0;
+   switch(signo)
+                                         
+   {
+ #ifdef SIGSEGV
+   case SIGSEGV:
+         /* Need to setup trapno and address */
+         mysinfo->si_trapno = proc_curilltrapno(pi);
+         mysinfo->si_addr = proc_curilladdr(pi);
+         break;
+ #endif
+ #ifdef SIGILL
+   case SIGILL:
+         /* Need to setup trapno and address */
+         mysinfo->si_trapno = proc_curilltrapno(pi);
+         mysinfo->si_addr = proc_curilladdr(pi);
+         break;
+ #endif
+   default:
    mysinfo->si_pid   = getpid ();       /* ?why? */
    mysinfo->si_uid   = getuid ();       /* ?why? */
!   break;
!   }
  #ifdef NEW_PROC_API
    arg.cmd = PCSSIG;
    win = (write (pi->ctl_fd, (void *) &arg, sizeof (arg))  == sizeof (arg));
***************
*** 4166,4173 ****
  #endif
                  wstat = (SIGTRAP << 8) | 0177;
                  break;
-               case FLTSTACK:
                case FLTACCESS:
  #if (FLTBOUNDS != FLTSTACK)   /* avoid "duplicate case" error */
                case FLTBOUNDS:
  #endif
--- 4221,4230 ----
  #endif
                  wstat = (SIGTRAP << 8) | 0177;
                  break;
                case FLTACCESS:
+                 wstat = (SIGBUS << 8) | 0177;
+                 break;
+               case FLTSTACK:
  #if (FLTBOUNDS != FLTSTACK)   /* avoid "duplicate case" error */
                case FLTBOUNDS:
  #endif