Valgrind can't find debug symbols, even with --extra-debuginfo-path
I'm attempting to install Valgrind on an embedded Debian-based PowerPC system. I've managed to cross-compile it successfully, but now it's complaining that it can't find debug information. I've put non-stripped copies of the relevant shared objects onto the filesystem and informed Valgrind of this directory, but it's still not working.
Invocation:
[email protected]:/# /root/valgrind/bin/valgrind --extra-debuginfo-path=/root/valgrind/usr/lib/debug /path/to/my_program -log
==6000== Memcheck, a memory error detector
==6000== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==6000== Using Valgrind-3.10.0.SVN and LibVEX; rerun with -h for copyright info
==6000== Command: /path/to/my_program -log
==6000==
valgrind: Fatal error at startup: a function redirection
valgrind: which is mandatory for this platform-tool combination
valgrind: cannot be set up. Details of the redirection are:
valgrind:
valgrind: A must-be-redirected function
valgrind: whose name matches the pattern: strlen
valgrind: in an object with soname matching: ld.so.1
valgrind: was not found whilst processing
valgrind: symbols from the object with soname: ld.so.1
valgrind:
valgrind: Possible fixes: (1, short term): install glibc's debuginfo
valgrind: package on this machine. (2, longer term): ask the packagers
valgrind: for your Linux distribution to please in future ship a non-
valgrind: stripped ld.so (or whatever the dynamic linker .so is called)
valgrind: that exports the above-named function using the standard
valgrind: calling conventions for this platform. The package you need
valgrind: to install for fix (1) is called
valgrind:
valgrind: On Debian, Ubuntu: libc6-dbg
valgrind: On SuSE, openSuSE, Fedora, RHEL: glibc-debuginfo
valgrind:
valgrind: Cannot continue -- exiting now. Sorry.
The offending file, ld.so.1, is in /lib, and my non-stripped copies are in a separate directory:
[email protected]:/# find / -name ld.so.1
/lib/ld.so.1
/root/valgrind/usr/lib/debug/ld.so.1
/root/valgrind/usr/lib/debug/lib/ld.so.1
My non-stripped copies from libc6-dbg_2.7-10ubuntu3_powerpc.deb appear to be compatible:
[email protected]:/# file /lib/ld.so.1 /root/valgrind/usr/lib/debug/ld.so.1 /root/valgrind/usr/lib/debug/lib/ld.so.1
/lib/ld.so.1: symbolic link to `ld-2.7.so'
/root/valgrind/usr/lib/debug/ld.so.1: symbolic link to `ld-2.7.so'
/root/valgrind/usr/lib/debug/lib/ld.so.1: symbolic link to `ld-2.7.so'
[email protected]:/# file /lib/ld-2.7.so /root/valgrind/usr/lib/debug/ld-2.7.so /root/valgrind/usr/lib/debug/lib/ld-2.7.so
/lib/ld-2.7.so: ELF 32-bit MSB shared object, PowerPC or cisco 4500, version 1 (SYSV), dynamically linked, with unknown capability 0x41000000 = 0x11676e75, with unknown capability 0x10000 = 0x90401, stripped
/root/valgrind/usr/lib/debug/ld-2.7.so: ELF 32-bit MSB shared object, PowerPC or cisco 4500, version 1 (SYSV), dynamically linked, not stripped
/root/valgrind/usr/lib/debug/lib/ld-2.7.so: ELF 32-bit MSB shared object, PowerPC or cisco 4500, version 1 (SYSV), statically linked, not stripped
And if I understand how objdump works, it seems like the "must-be-redirected function" mentioned by Valgrind does indeed have an entry in the debug copy:
[email protected]:/# objdump -x /lib/ld-2.7.so | grep strlen
[email protected]:/# objdump -x /root/valgrind/usr/lib/debug/lib/ld-2.7.so | grep strlen
0002f734 l O .data.rel.ro 00000004 max_capstrlen
00018ff0 l F .text 000000b8 strlen
And yet the --extra-debuginfo-path argument has no effect. There's a brief mention of this switch in the manual, but this is practically all the information I've been able to find about it. Am I missing something else?
For the record, this machine cannot connect to the Internet, so letting apt / dpkg take care of things is sadly out of the question. /lib and most other system directories are also mounted read-only, so I can't just drop in a non-stripped replacement for ld-2.7.so (not that I would take such a risk).
I had a similar issue, and adding --allow-mismatched-debuginfo=yes parameter to valgrind solved the problem.