Program received signal SIGINT, Interrupt.
0x9242d4a6 in mach_msg_trap ()
Error while running hook_stop:
Invalid type combination in ordering comparison.

This behavior happens regardless of the program being debugged.

also whenever I type context on I get:

————————————————————————–[regs]
EAX: 10004005 EBX: 91D849E7 ECX: BFFFE8BC EDX: 9242D4A6 o d I t s z a P c
ESI: 00000000 EDI: 00000000 EBP: BFFFE8F8 ESP: BFFFE8BC EIP: 9242D4A6
CS: 0007 DS: 001F ES: 001F FS: 0000 GS: 0037 SS: 001F
[001F:BFFFE8BC]———————————————————-[stack]
Invalid type combination in ordering comparison.

Any suggestions? Please???

Just execute gdb without any parameters.
Then you can attach to a process via PID or debug a new executable with the command “exec-file path_to_executable”
Setup a breakpoint where you want and start program with “run” command.
Help user displays the custom commands provided by this gdbinit.

fG!

i put the .gdbinit file in my home folder but don’t work.

how to use ?
gdb command ?

I didn’t knew where to write this, so i’m putting it in first news comment. I was wondering do you guys have some form of IRC channel or forum where you can discuss/ask different types of things about RCE on MacOS ? I have quite few questions (mainly regarding remote debugging using IDA) and i would gladly discuss about mac rce

Cheers, and keep up the good work.

/gln

The bug was something like:
If (condition)
do something here
else
end

Leaving the else empty makes gdb segfault ! Crazyyyyyy…..!

– beowulf

Can you mail me your binary to reverse AT put.as ?

Thanks for the code, just included it in this version.

“set $SHOWOBJECTIVEC = 0″ does the trick for me, works like a charm. Thanks!
Btw, here’s a modified version of the “nop” command which allows you to patch a series of bytes instead of just one. Hope it comes in handy, enjoy.
—————————-8<—————————-
define nop
if ($argc 2)
help nop
end

if ($argc == 1)
set *(unsigned char *)$arg0 = 0×90
else
set $addr = $arg0
while ($addr < $arg1)
set *(unsigned char *)$addr = 0×90
set $addr = $addr + 1
end
end
end
document nop
Patch a single byte at address ADDR1, or a series of bytes between ADDR1 and
ADDR2 to a nop (0×90) instruction.
Usage: nop ADDR1 ADDR2
end
—————————-8<—————————-

Try to change this option to 0 in gdbinit: set $SHOWOBJECTIVEC = 0

– beowulf

Of course, I’m using OS X 10.5.6 with GNU gdb 6.3.50-20050815 (Apple version gdb-962).

$ cat test.c
#include
int main(void) { return 0; }
$ make test >/dev/null
$ gdb -silent
gdb$ exec-file test
Reading symbols for shared libraries … done
gdb$ break *0x00001ff5
Breakpoint 1 at 0x1ff5
gdb$ r
Reading symbols for shared libraries …. done

Breakpoint 1, 0x00001ff5 in main ()
————————————————————————–[regs]
EAX: 00000000 EBX: BFFFFA58 ECX: BFFFF9F0 EDX: 00000000 o d I t s Z a P c
ESI: 00000000 EDI: 00000000 EBP: BFFFF9C8 ESP: BFFFF9C8 EIP: 00001FF5
CS: 0017 DS: 001F ES: 001F FS: 0000 GS: 0037 SS: 001F
[001F:BFFFF9C8]———————————————————-[stack]
BFFFFA18 : 88 FB FF BF 93 FB FF BF – A9 FB FF BF D4 FB FF BF …………….
BFFFFA08 : F5 FA FF BF 00 FB FF BF – 3A FB FF BF 6F FB FF BF ……..:…o…
BFFFF9F8 : 86 FA FF BF BF FA FF BF – DB FA FF BF E5 FA FF BF …………….
BFFFF9E8 : 00 00 00 00 01 00 00 00 – 74 FA FF BF 00 00 00 00 ……..t…….
BFFFF9D8 : F8 F9 FF BF 58 FA FF BF – 00 00 00 00 00 00 00 00 ….X………..
BFFFF9C8 : E8 F9 FF BF C6 1F 00 00 – 01 00 00 00 F0 F9 FF BF …………….
Segmentation fault
$

Quite annoying… But as i said before, if i use “context-off”, it works flawlessly, i’m guessing it crashes when displaying the disassembly.

I’m using OS X 10.4.11 with Apple gdb 7.68 (GNU gdb 6.3.50-20050815 (Apple version gdb-696) (Sat Oct 20 18:16:54 GMT 2007)).
What versions are you using ? What program are you trying to debug ? Can you paste the segfault ?

Thx,
fG!

Are you (or anybody else) experiencing crashes on OS X with this gdbinit? It works fine for me on Linux, but on OS X it makes gdb segfault (but only when im running with context-on). Any ideas?

– beowulf