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Valgrind again: strlen() redirection

Christian Kruse,

I ran into another problem with Valgrind:

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-linux-x86-64.so.2 valgrind: was not found whilst processing
valgrind: symbols from the object with soname: ld-linux-x86-64.so.2 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. valgrind: valgrind: Cannot continue -- exiting now. Sorry.

I already was familiar with this problem and I knew using FEATURES="nostrip" and a re-emerge of sys-libs/glibc should help. But after doing that the problem was not gone. After some research I found out that with -O2 the GCC inlines strlen(). It is a code optimization, but in this case it causes valgrind to stop working. The solution is somewhat messy: you have to create a portage overlay of sys-libs/glibc and patch files/eblits/common.eblit: find the line containing append-flags -O2 -fno-strict-aliasing and append -fno-builtin-strlen. Then re-emerge glibc (do not forget to run ebuild glibc-ver.ebuild digest) and everything should work.