Gentoo fPIE & Ubuntu addr2line issue for executable about malt HOT 10 CLOSED

In case someone want to look :

from malt.

Seems to have improvement with -j .text on addr2line but that does not solve all.

from malt.

That should be due to KASLR, solution might be to inspirate from what is one in : https://github.com/torvalds/linux/blob/master/scripts/faddr2line

from malt.

Solution might be coming from here : https://jvns.ca/blog/2018/01/09/resolving-symbol-addresses/

At least in code on my exemple it works by doing this by hand :

addr2lineCmd << ' '  << (void*)(((size_t)it->first - (size_t)procMapEntry->lower) + (size_t)0x402270);

With 0x402270 coming from readelf -h simple-case-finstr-linked or objdump (Entry point address or vaddr).

from malt.

This should also fix on other distro which now also enable by default fPIE and ASLR

from malt.

Damn, still get issue on Gentoo, there is a gap with what happen on Centos/Redhat.

On Centos/Redhat, this is OK for the main binary:

addr2lineCmd << ' '  << (void*)(((size_t)it->first - (size_t)procMapEntry->lower));

On Gentoo I need:

addr2lineCmd << ' '  << (void*)(((size_t)it->first - (size_t)procMapEntry->lower + elfVaddr));

Need to find a way to automatically detect case or add an option for last resort.

Possibility:

• OS version checking (not nice)
• Test the two case and check which one return a valid line (also not nice, can return another location on big binaries).
• really understand (would be nice).

from malt.

Also have issue on Ubuntu 19/04

from malt.

Other infos related : https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=860394

from malt.

One can temporarily solve the issue vy --no-pie the compilation of the executables to be profiled. But that's not a real solution for long term.

from malt.

Finally found a solution by looking here : https://stackoverflow.com/questions/55066749/how-to-find-load-relocation-for-a-pie-binary

from malt.