[PATCH] Fix memory leak in solib-svr4.c

[Kevin Buettner <kevinb@redhat.com>]

I've just committed the patch below.

It fixes a memory leak in solib-svr4.c.  In enable_break(), the memory
allocated by svr4_current_sos() was never being freed.

I could have iterated over the list returned by this function and
freed each entry, but, instead, I chose to eliminate the call to
svr4_current_sos() altogether.  It appears to me that the call to
svr4_current_sos() was being used for two purposes: 1) to determine
whether or not to call solib_add(), and 2) as a means for finding
the dynamic linker's base address.  solib_add() makes its own call
to svr4_current_sos(), which means that svr4_current_sos() was
being invoked an extra time for no good reason (that I can see).
The code has been reorganized to instead use the master list
operated on by solib_add().

Kevin

	* solist.h (master_so_list): New function.
	* solib.c (master_so_list): Likewise.
	* solib-svr4.c (enable_break): Iterate over so_list entries
	obtained from master list instead of entries obtained directly
	via svr4_current_sos().

Index: solib-svr4.c
===================================================================
RCS file: /cvs/src/src/gdb/solib-svr4.c,v
retrieving revision 1.41
diff -c -p -r1.41 solib-svr4.c
*** solib-svr4.c	21 Feb 2004 18:34:45 -0000	1.41
--- solib-svr4.c	11 Mar 2004 16:57:35 -0000
*************** enable_break (void)
*** 1004,1010 ****
        char *buf;
        CORE_ADDR load_addr = 0;
        int load_addr_found = 0;
!       struct so_list *inferior_sos;
        bfd *tmp_bfd = NULL;
        struct target_ops *tmp_bfd_target;
        int tmp_fd = -1;
--- 1004,1010 ----
        char *buf;
        CORE_ADDR load_addr = 0;
        int load_addr_found = 0;
!       struct so_list *so;
        bfd *tmp_bfd = NULL;
        struct target_ops *tmp_bfd_target;
        int tmp_fd = -1;
*************** enable_break (void)
*** 1047,1069 ****
           target will also close the underlying bfd.  */
        tmp_bfd_target = target_bfd_reopen (tmp_bfd);
  
!       /* If the entry in _DYNAMIC for the dynamic linker has already
!          been filled in, we can read its base address from there. */
!       inferior_sos = svr4_current_sos ();
!       if (inferior_sos)
  	{
! 	  /* Connected to a running target.  Update our shared library table. */
! 	  solib_add (NULL, 0, NULL, auto_solib_add);
! 	}
!       while (inferior_sos)
! 	{
! 	  if (strcmp (buf, inferior_sos->so_original_name) == 0)
  	    {
  	      load_addr_found = 1;
! 	      load_addr = LM_ADDR (inferior_sos);
  	      break;
  	    }
! 	  inferior_sos = inferior_sos->next;
  	}
  
        /* Otherwise we find the dynamic linker's base address by examining
--- 1047,1065 ----
           target will also close the underlying bfd.  */
        tmp_bfd_target = target_bfd_reopen (tmp_bfd);
  
!       /* On a running target, we can get the dynamic linker's base
!          address from the shared library table.  */
!       solib_add (NULL, 0, NULL, auto_solib_add);
!       so = master_so_list ();
!       while (so)
  	{
! 	  if (strcmp (buf, so->so_original_name) == 0)
  	    {
  	      load_addr_found = 1;
! 	      load_addr = LM_ADDR (so);
  	      break;
  	    }
! 	  so = so->next;
  	}
  
        /* Otherwise we find the dynamic linker's base address by examining
Index: solib.c
===================================================================
RCS file: /cvs/src/src/gdb/solib.c,v
retrieving revision 1.63
diff -c -p -r1.63 solib.c
*** solib.c	28 Feb 2004 18:04:37 -0000	1.63
--- solib.c	11 Mar 2004 16:57:35 -0000
*************** free_so (struct so_list *so)
*** 333,338 ****
--- 333,346 ----
  }
  
  
+ /* Return address of first so_list entry in master shared object list.  */
+ struct so_list *
+ master_so_list (void)
+ {
+   return so_list_head;
+ }
+ 
+ 
  /* A small stub to get us past the arg-passing pinhole of catch_errors.  */
  
  static int
Index: solist.h
===================================================================
RCS file: /cvs/src/src/gdb/solist.h,v
retrieving revision 1.8
diff -c -p -r1.8 solist.h
*** solist.h	24 Feb 2003 19:11:04 -0000	1.8
--- solist.h	11 Mar 2004 16:57:35 -0000
*************** struct target_so_ops
*** 107,113 ****
--- 107,117 ----
      
    };
  
+ /* Free the memory associated with a (so_list *).  */
  void free_so (struct so_list *so);
+ 
+ /* Return address of first so_list entry in master shared object list.  */
+ struct so_list *master_so_list (void);
  
  /* Find solib binary file and open it.  */
  extern int solib_open (char *in_pathname, char **found_pathname);