[PATCH] D61824: [ARM][AArch64] Overalign SHF_TLS instead of PT_TLS (Android Bionic hack) to make glibc happy

[Rich Felker via Phabricator via llvm-commits]

dalias added a comment.

I do not see how .tdata happening to be the first thing in the LOAD segment is relevant or helpful at all. Any "accidental alignment" as a result of that is not part of the alignment that will affect the runtime addresses of TLS objects.

I find the whole approach of using ridiculous amounts of alignment to produce a gap for Bionic to be highly misguided. It imposes significant amounts of wasted memory, and is a roundabout way of doing what you really want to do, which is just *allocating* 8 words of reserved TLS at the beginning of the main program's TLS image, for Bionic. This could be done directly either in Bionic's crt files, or in LLD as a Bionic-specific hack that just emits 8 words at the beginning of .tdata. Nowhere is there any reason to touch alignment or impose these costs on non-buggy (non-Bionic) implementations.


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https://reviews.llvm.org/D61824