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From: Tavis Ormandy <taviso@gmail.com>
Subject: making stabs visible to gdb
Date: Wed, 3 Aug 2022 05:11:46 -0000 (UTC)
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Hello, I have a stripped binary I don't have the source for that I would
like to debug in gdb. I thought writing some .stabs statements in gas
would be a nice easy way to record the symbols I know about, like this:

.equ N_FUN, 0x24
.equ N_PSYM, 0xa0
.stabs "example:f-11", N_FUN, 0, 0, 0x8005bba
.stabs "foo:p*-8", N_PSYM, 0, 0, 8
.stabs "bar:p-10", N_PSYM, 0, 0, 12

https://sourceware.org/binutils/docs/as/Stab.html

I think this describes a function like this at address 0x8005bba:

void example(unsigned int *foo, unsigned long bar)

If I assemble that (as -gstabs), then add-symbol-file a.out, gdb knows
about it but won't resolve it in backtraces.

(gdb) add-symbol-file a.out
(gdb) info address example
Symbol "example" is a function at address 0x8005bba.
(gdb) pt example
type = void (unsigned int *, unsigned long)
(gdb) bt
..
#1  0x0000000008005bba in ?? ()     <-- unresolved
..

What am I doing wrong?

Also, is there a better way to accomplish what I'm trying to do?

Tavis.

-- 
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