🚀 go-pugleaf

Here is what I get if I try to run GDB on itself:



wollman@sal(25)$ ./gdb ./gdb
GDB is free software and you are welcome to distribute copies of it
 under certain conditions; type "show copying" to see the conditions.
There is absolutely no warranty for GDB; type "show warranty" for details.
GDB 4.6, Copyright 1992 Free Software Foundation, Inc...
Setting up the environment for debugging gdb.
During symbol reading, guessed tag type of struct sigaction incorrectly.
During symbol reading, stEnd with storage class 1 not handled.
Breakpoint 1 at 0x42af78: file ../../gdb/gdb/utils.c, line 294.
Breakpoint 2 at 0x40217c: file ../../gdb/gdb/main.c, line 1667.
(top-gdb) i break
Num Type           Disp Enb Address    What
1   breakpoint     keep y   0x0042af78 in fatal_dump_core at ../../gdb/gdb/utils.c:294
2   breakpoint     keep y   0x0040217c in show_command at ../../gdb/gdb/main.c:1667
        silent
        return

Note that breakpoint 2 is supposed to be in `info_command', *not*
`show_command'.  If I set a breakpoint at `main', run the program, and
then try to `next' it when the breakpoint gets hit, the inferior runs
for a while and hangs; if I interrupt it and then continue with
`signal 0' it starts running.  (It never stops for what should have
been the `next' line.)  Entering `show' in the inferior gdb causes the
parent GDB to hang, and if I kill it with a SIGILL, it leaves an
interesting core file.

Here's the rest of the transcript...

(top-gdb) br main
Breakpoint 3 at 0x400548: file ../../gdb/gdb/main.c, line 415.
(top-gdb) run
Starting program: /a/trantor/usr/src/tools/checkout/gdb.iris/gdb/gdb

Breakpoint 3, 0x400548 in main (argc=0, argv=0x0) at ../../gdb/gdb/main.c:415
415          int argc;
(top-gdb) n

Program received signal 2, Interrupt
getcwd () at getcwd.c:40
getcwd.c:40: No such file or directory.
(top-gdb) bt
#0  getcwd () at getcwd.c:40
#1  0x400604 in main (argc=1, argv=0x7fffc764) at ../../gdb/gdb/main.c:415
(top-gdb) signal 0
Continuing with signal 0.
GDB is free software and you are welcome to distribute copies of it
 under certain conditions; type "show copying" to see the conditions.
There is absolutely no warranty for GDB; type "show warranty" for details.
GDB 4.6, Copyright 1992 Free Software Foundation, Inc.
Setting up the environment for debugging gdb.
No symbol table is loaded.  Use the "file" command.
(gdb) show

[2]+  Stop signal from tty    ./gdb ./gdb
wollman@sal(26)$ kill -ILL %2

[. . .]

wollman@sal(30)$ dbx ./gdb core
dbx version 2.10 11/15/91 2:02
Type 'help' for help.
Reading symbolic information of `./gdb' . . .
Process name from core dump: gdb
Process died at pc 0x431b30 of signal : Segmentation fault
[using memory image in core]
(dbx) where
>  0 mips_pop_frame(0x1005b010, 0x1, 0x1a, 0x1006d108, 0x0, 0x1) ["../../gdb/gdb/mips-tdep.c":501, 0x431b2c]
   1 return_command(retval_exp = (nil), from_tty = 0) ["../../gdb/gdb/stack.c":1123, 0x40a548]
   2 execute_command(p = 0x10059f5e = "", from_tty = 0) ["../../gdb/gdb/main.c":865, 0x401178]
   3 bpstat_do_actions(bsp = 0x10032be0) ["../../gdb/gdb/breakpoint.c":665, 0x404c60]
   4 command_loop(0x1005b010, 0x1, 0x1a, 0x1006d108, 0x38, 0x402658) ["../../gdb/gdb/main.c":958, 0x401338]
   5 .main.main(argc = 2, argv = 0x7fffc76c) ["../../gdb/gdb/main.c":415, 0x400f84]
   6 mips_pop_frame(0x1005b010, 0x1, 0x1a, 0x1006d108, 0x7fffc89a, 0x7fffc8d1) ["../../gdb/gdb/mips-tdep.c":501, 0x431b20]
   7 <past end of a.out text>(0x1005b010, 0x1, 0x1a, 0x1006d108, 0xffffffff, 0xffffffff) [0x7fffc7ec]

warning: address 0xfffffffc for 4 bytes is not in the core file

warning: address 0xfffffffc for 4 bytes is not in the core file
(dbx)

sal.emba.uvm.edu is a 4D/310 Power Series machine with an IP7
processor card (R3000 3.0, R3010 4.0).  It currently runs Irix 4.0.
GDB was compiled using GCC 2.2.2, running on the same machine.

I can provide a copy of the binary for anyone who is interested; if I
get the time I will look int othis problem myself, starting with a
diff between 4.4 and 4.5 procfs.c...

-GAWollman

-- 
   Garrett A. Wollman  = wollman@emba.uvm.edu = UVM is welcome to my opinions
                       =    uvm-gen!wollman   =
   That's what being alive is all about.  No deity, no higher goal
   exists, than to bring joy to another person.    - Elf Sternberg