[RFA] mips find_proc_desc()

[RFA] mips find_proc_desc()

[Martin M. Hunt]

In mips-tdep.c, we have

static mips_extra_func_info_t
find_proc_desc (CORE_ADDR pc, struct frame_info *next_frame, int cur_frame)
{
  mips_extra_func_info_t proc_desc;
  CORE_ADDR startaddr;

  proc_desc = non_heuristic_proc_desc (pc, &startaddr);
  if (proc_desc)
    {
      [...]
    }
 else
    {
      [...]
      if (startaddr == 0)
        startaddr = heuristic_proc_start (pc);
    }
}

and we have

static mips_extra_func_info_t
non_heuristic_proc_desc (CORE_ADDR pc, CORE_ADDR *addrptr)
{
  CORE_ADDR startaddr;
  mips_extra_func_info_t proc_desc;
  struct block *b = block_for_pc (pc);
  struct symbol *sym;
  struct obj_section *sec;
  struct mips_objfile_private *priv;

  if (PC_IN_CALL_DUMMY (pc, 0, 0))
    return NULL;
  [...]
}

Looking at "startaddr" in find_proc_desc(), it is passed into 
non_heuristic_proc_desc uninitialized and never initialized if 
PC_IN_CALL_DUMMY().  Nevertheless find_proc_desc attempts to use it anyway.

There are several simple fixes.  The easiest is to initialize it to 0 as it 
appears that is what find_proc_desc() expects.

-- 
Martin Hunt
GDB Engineer
Red Hat, Inc.


2002-09-26  Martin M. Hunt  <hunt@redhat.com>

        * mips-tdep.c (find_proc_desc): Initialize startaddr.


Index: mips-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/mips-tdep.c,v
retrieving revision 1.126
diff -u -u -r1.126 mips-tdep.c
--- mips-tdep.c 18 Sep 2002 15:37:18 -0000      1.126
+++ mips-tdep.c 26 Sep 2002 22:01:54 -0000
@@ -2336,7 +2336,7 @@
 find_proc_desc (CORE_ADDR pc, struct frame_info *next_frame, int cur_frame)
 {
   mips_extra_func_info_t proc_desc;
-  CORE_ADDR startaddr;
+  CORE_ADDR startaddr = 0;

   proc_desc = non_heuristic_proc_desc (pc, &startaddr);

Re: [RFA] mips find_proc_desc()

[Andrew Cagney]

Yes, ok.


> In mips-tdep.c, we have
> 
> static mips_extra_func_info_t
> find_proc_desc (CORE_ADDR pc, struct frame_info *next_frame, int cur_frame)
> {
>   mips_extra_func_info_t proc_desc;
>   CORE_ADDR startaddr;
> 
>   proc_desc = non_heuristic_proc_desc (pc, &startaddr);
>   if (proc_desc)
>     {
>       [...]
>     }
>  else
>     {
>       [...]
>       if (startaddr == 0)
>         startaddr = heuristic_proc_start (pc);
>     }
> }
> 
> and we have
> 
> static mips_extra_func_info_t
> non_heuristic_proc_desc (CORE_ADDR pc, CORE_ADDR *addrptr)
> {
>   CORE_ADDR startaddr;
>   mips_extra_func_info_t proc_desc;
>   struct block *b = block_for_pc (pc);
>   struct symbol *sym;
>   struct obj_section *sec;
>   struct mips_objfile_private *priv;
> 
>   if (PC_IN_CALL_DUMMY (pc, 0, 0))
>     return NULL;
>   [...]
> }
> 
> Looking at "startaddr" in find_proc_desc(), it is passed into 
> non_heuristic_proc_desc uninitialized and never initialized if 
> PC_IN_CALL_DUMMY().  Nevertheless find_proc_desc attempts to use it anyway.
> 
> There are several simple fixes.  The easiest is to initialize it to 0 as it 
> appears that is what find_proc_desc() expects.
> 
> -- Martin Hunt GDB Engineer Red Hat, Inc. 2002-09-26 Martin M. Hunt <hunt@redhat.com> * mips-tdep.c (find_proc_desc): Initialize startaddr. Index: mips-tdep.c =================================================================== RCS file: /cvs/src/src/gdb/mips-tdep.c,v retrieving revision 1.126 diff -u -u -r1.126 mips-tdep.c --- mips-tdep.c 18 Sep 2002 15:37:18 -0000 1.126 +++ mips-tdep.c 26 Sep 2002 22:01:54 -0000 @@ -2336,7 +2336,7 @@ find_proc_desc (CORE_ADDR pc, struct frame_info *next_frame, int cur_frame) { mips_extra_func_info_t proc_desc; - CORE_ADDR startaddr; + CORE_ADDR startaddr = 0; proc_desc = non_heuristic_proc_desc (pc, &startaddr);