Support separate loading debug symbols

[XVilka]

For example in Gentoo with 'splitdebug' option: https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces#Stripping

r2 -d /bin/ls
Process with PID 28255 started...
= attach 28255 28255
bin.baddr 0x00400000
Assuming filepath /bin/ls
asm.bits 64
[0x7f2895c79c80]> dm
sys 120K 0x0000000000400000 - 0x000000000041e000 s -r-x /bin/ls /bin/ls
sys   8K 0x000000000061d000 - 0x000000000061f000 s -rw- /bin/ls /bin/ls
sys   4K 0x000000000061f000 - 0x0000000000620000 s -rw- unk0 unk0
sys 140K 0x00007f2895c79000 * 0x00007f2895c9c000 s -r-x /lib64/ld-2.23.so /lib64/ld-2.23.so
sys   8K 0x00007f2895e9c000 - 0x00007f2895e9e000 s -rw- /lib64/ld-2.23.so /lib64/ld-2.23.so
sys   4K 0x00007f2895e9e000 - 0x00007f2895e9f000 s -rw- unk1 unk1
sys 136K 0x00007ffd8b8ff000 - 0x00007ffd8b921000 s -rw- [stack] [stack]
sys  12K 0x00007ffd8b9ac000 - 0x00007ffd8b9af000 s -r-- [vvar] [vvar]
sys   8K 0x00007ffd8b9af000 - 0x00007ffd8b9b1000 s -r-x [vdso] [vdso]
sys   4K 0xffffffffff600000 - 0xffffffffff601000 s -r-x [vsyscall] [vsyscall]
[0x7f2895c79c80]> dmh
Warning: Is glibc mapped in memory? (see dm command)
[0x7f2895c79c80]> db main
[0x7f2895c79c80]> dc
hit breakpoint at: 4027e0
= attach 28255 1
[0x004027e0]> dm
sys 120K 0x0000000000400000 * 0x000000000041e000 s -r-x /bin/ls /bin/ls
sys   4K 0x000000000061d000 - 0x000000000061e000 s -r-- /bin/ls /bin/ls
sys   4K 0x000000000061e000 - 0x000000000061f000 s -rw- /bin/ls /bin/ls
sys   4K 0x000000000061f000 - 0x0000000000620000 s -rw- unk0 unk0
sys 1.6M 0x00007f28958df000 - 0x00007f2895a6f000 s -r-x /lib64/libc-2.23.so /lib64/libc-2.23.so
sys   2M 0x00007f2895a6f000 - 0x00007f2895c6f000 s ---- /lib64/libc-2.23.so /lib64/libc-2.23.so
sys  16K 0x00007f2895c6f000 - 0x00007f2895c73000 s -r-- /lib64/libc-2.23.so /lib64/libc-2.23.so
sys   8K 0x00007f2895c73000 - 0x00007f2895c75000 s -rw- /lib64/libc-2.23.so /lib64/libc-2.23.so
sys  16K 0x00007f2895c75000 - 0x00007f2895c79000 s -rw- unk1 unk1
sys 140K 0x00007f2895c79000 - 0x00007f2895c9c000 s -r-x /lib64/ld-2.23.so /lib64/ld-2.23.so
sys  12K 0x00007f2895e5d000 - 0x00007f2895e60000 s -rw- unk2 unk2
sys   4K 0x00007f2895e9b000 - 0x00007f2895e9c000 s -rw- unk3 unk3
sys   4K 0x00007f2895e9c000 - 0x00007f2895e9d000 s -r-- /lib64/ld-2.23.so /lib64/ld-2.23.so
sys   4K 0x00007f2895e9d000 - 0x00007f2895e9e000 s -rw- /lib64/ld-2.23.so /lib64/ld-2.23.so
sys   4K 0x00007f2895e9e000 - 0x00007f2895e9f000 s -rw- unk4 unk4
sys 136K 0x00007ffd8b8ff000 - 0x00007ffd8b921000 s -rw- [stack] [stack]
sys  12K 0x00007ffd8b9ac000 - 0x00007ffd8b9af000 s -r-- [vvar] [vvar]
sys   8K 0x00007ffd8b9af000 - 0x00007ffd8b9b1000 s -r-x [vdso] [vdso]
sys   4K 0xffffffffff600000 - 0xffffffffff601000 s -r-x [vsyscall] [vsyscall]
[0x004027e0]> dmh
Is a custom library? (LD_PRELOAD=..) Enter full path glibc: /lib/libc.so.6
Warning: Symbol main_arena could not be found. Is libc6-dbg installed?
[0x004027e0]>

[XVilka]

@n4x0r

[XVilka]

It's located at /usr/lib/debug/lib64/libc-2.23.so.debug, since /lib/libc.so.6 is a symlink to /lib/libc-2.23.so, so the 'prefix' is /usr/lib/debug

[radare]

This is already possible with oa command, please confirm i did this last week

[radare]

this can be done with ob and oa, but its just not done "automatically". so considered fixed, but keeping it open until someone writes a test

[XVilka]

I know it can be done in manual mode, but it's just a few distributives, gdb does that automatically, would be nice to have that for r2. I'll fix it by myself when I have time (since nobody even cares except me), should be very easy.

[ulexec]

Im restricted on time atm if not i would have done it already. is not that u are the only one that cares xvilka cmon :_(

[jduck]

@XVilka I care too!