[RFA] rs6000-nat.c fix for large symtabs.

[Chris Faylor]

On Fri, Apr 07, 2000 at 02:42:45PM -0700, glen mccready wrote:
>
>Some processes have more than 64 load segments; in the past gdb
>would fail under these circumstances.  This patch should alleviate
>that problem by expanding the buffer if the ld_info won't fit.

Would it be feasible to do this with malloc/realloc instead of alloca in
this case?  Otherwise you could be wasting a lot of stack space.

cgf

>Fri Apr  7 13:44:38 2000  glen mccready  <gkm@pobox.com>
>
>	* rs6000-nat.c (xcoff_relocate_symtab): Grow buffer if ptrace()
>	  fails due to lack of space.
>
>Index: rs6000-nat.c
>===================================================================
>retrieving revision 2.41.60.1
>diff -c -b -r2.41.60.1 rs6000-nat.c
>*** rs6000-nat.c	2000/02/14 04:31:53	2.41.60.1
>--- rs6000-nat.c	2000/04/07 21:41:41
>***************
>*** 639,649 ****
>  xcoff_relocate_symtab (pid)
>       unsigned int pid;
>  {
>! #define	MAX_LOAD_SEGS 64	/* maximum number of load segments */
>  
>    struct ld_info *ldi;
>  
>!   ldi = (void *) alloca (MAX_LOAD_SEGS * sizeof (*ldi));
>  
>    /* According to my humble theory, AIX has some timing problems and
>       when the user stack grows, kernel doesn't update stack info in time
>--- 639,654 ----
>  xcoff_relocate_symtab (pid)
>       unsigned int pid;
>  {
>!   int load_segs = 64; /* number of load segments */
>!   int rc;
>  
>+   do
>+     {
>    struct ld_info *ldi;
>  
>!       ldi = (void *) alloca (load_segs * sizeof (*ldi));
>!       if (ldi == 0)
>! 	perror_with_name ("xcoff_relocate_symtab");
>  
>    /* According to my humble theory, AIX has some timing problems and
>       when the user stack grows, kernel doesn't update stack info in time
>***************
>*** 653,667 ****
>    usleep (36000);
>  
>    errno = 0;
>!   ptrace (PT_LDINFO, pid, (PTRACE_ARG3_TYPE) ldi,
>! 	  MAX_LOAD_SEGS * sizeof (*ldi), (int *) ldi);
>!   if (errno)
>      perror_with_name ("ptrace ldinfo");
>! 
>    vmap_ldinfo (ldi);
>! 
>!   /* relocate the exec and core sections as well. */
>!   vmap_exec ();
>  }
>  
>  /* Core file stuff.  */
>--- 658,678 ----
>    usleep (36000);
>  
>    errno = 0;
>!       rc = ptrace (PT_LDINFO, pid, (PTRACE_ARG3_TYPE) ldi,
>! 	      load_segs * sizeof (*ldi), (int *) ldi);
>!       if (rc == -1)
>!         {
>! 	if (errno == ENOMEM)
>! 	  load_segs *= 2;
>! 	else
>      perror_with_name ("ptrace ldinfo");
>!         }
>!       else
>! 	{
>    vmap_ldinfo (ldi);
>! 	  vmap_exec (); /* relocate the exec and core sections as well. */
>! 	}
>!     } while (rc == -1);
>  }
>  
>  /* Core file stuff.  */

-- 
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