Bug 505943

Description of problem:
Putting a future breakpoint on a library in a pie executable crashes gdb when library is loaded.

Version-Release number of selected component (if applicable):
GNU gdb (GDB) Fedora (6.8.50.20090302-23.fc11)

How reproducible:
Always

Steps to Reproduce:
1. cat main.c
#include <stdio.h>

// function from our library
int func (void);

int
main (int argc, char *argv[], char *envp[])
{
  printf("main\n");
  func ();
  return 0;
}

2. cat library.c
#include <stdio.h>

static void
lib_func ()
{
  printf("lib_func\n");
}

void
func ()
{
  printf("func\n");
}

3. gcc library.c -g -O0 -fPIC -shared -o liblibrary.so

4. gcc main.c -fPIE -pie -g -O0 -L. -llibrary -Wl,-rpath,. -o main

5. gdb main
(gdb) break lib_func
Function "lib_func" not defined.
Make breakpoint pending on future shared library load? (y or [n]) y

Breakpoint 1 (lib_func) pending.
(gdb) run
Starting program: /home/mark/src/tests/main 
Segmentation fault

If the executable isn't compile -pie future breakpoint works as expected.

Additional info:

Running gdb under gdb shows a segfault:

Program received signal SIGSEGV, Segmentation fault.
0x00000000004c63dd in disable_breakpoints_at_startup (silent=1)
    at ../../gdb/breakpoint.c:5026
5026		      !b->loc->duplicate)
(gdb) bt
#0  0x00000000004c63dd in disable_breakpoints_at_startup (silent=1)
    at ../../gdb/breakpoint.c:5026
#1  0x00000000005069c7 in post_create_inferior (target=0xa0e380, from_tty=0)
    at ../../gdb/infcmd.c:423
#2  0x0000000000507249 in run_command_1 (args=0x0, from_tty=1, 
    tbreak_at_main=<value optimized out>) at ../../gdb/infcmd.c:569
#3  0x0000000000451969 in execute_command (p=0xe0c103 "", from_tty=1)
    at ../../gdb/top.c:450
#4  0x000000000051c325 in command_handler (command=0xe0c100 "")
    at ../../gdb/event-top.c:519
#5  0x000000000051cfec in command_line_handler (rl=<value optimized out>)
    at ../../gdb/event-top.c:744
#6  0x000000389ce27e2c in rl_callback_read_char () at ../callback.c:205
#7  0x000000000051c469 in rl_callback_read_char_wrapper (client_data=0x0)
    at ../../gdb/event-top.c:179
#8  0x000000000051adc8 in process_event () at ../../gdb/event-loop.c:394
#9  0x000000000051bfba in gdb_do_one_event (data=<value optimized out>)
    at ../../gdb/event-loop.c:459
#10 0x00000000005160eb in catch_errors (func=<value optimized out>, 
    func_args=<value optimized out>, errstring=<value optimized out>, 
    mask=<value optimized out>) at ../../gdb/exceptions.c:516
#11 0x00000000004a6d28 in tui_command_loop (data=<value optimized out>)
    at ../../gdb/tui/tui-interp.c:156
#12 0x00000000004449c9 in captured_command_loop (data=0x0)
    at ../../gdb/main.c:183
#13 0x00000000005160eb in catch_errors (func=<value optimized out>, 
    func_args=<value optimized out>, errstring=<value optimized out>, 
    mask=<value optimized out>) at ../../gdb/exceptions.c:516
#14 0x000000000044533e in captured_main (data=<value optimized out>)
    at ../../gdb/main.c:989
#15 0x00000000005160eb in catch_errors (func=<value optimized out>, 
    func_args=<value optimized out>, errstring=<value optimized out>, 
    mask=<value optimized out>) at ../../gdb/exceptions.c:516
#16 0x00000000004449b4 in gdb_main (args=0x0) at ../../gdb/main.c:999
#17 0x0000000000444989 in main (argc=<value optimized out>, argv=0x0)
    at ../../gdb/gdb.c:47