Currently, we are incorrectly building ld.so on x86-64 with SSE2 string functions. We want to fix this and switch to AVX2 strcmp, but this breaks valgrind. This was actually observed upstream, and papered over in the glibc test suite:

• [PATCH] x86_64: Suppress false positive valgrind error

However, this is just adding a suppression file to the glibc test suite, so it does not help when a properly built x86-64-v3 ld-linux-x86-64.so.2 is installed for distribution use.

I can provide a test system with a special glibc installed, or perhaps provide test RPMs.