TLSDESC is the default on aarch64. Clang doesn't support -mtls-dialect=trad. Its integrated assembler doesn't support the markers. LLD's doesn't support R_AARCH64_TLSGD_*/R_AARCH64_TLSLD_* relocations. Supporting the model has nearly zero value. These tests use TLS_GD/TLS_LD macros: M elf/tst-tls1.c M elf/tst-tls2.c M elf/tst-tls3.c M elf/tst-tlsmod1.c M elf/tst-tlsmod2.c M elf/tst-tlsmod3.c M elf/tst-tlsmod4.c They can be disabled when CC is Clang or LD is LLD.
https://sourceware.org/pipermail/libc-alpha/2021-August/129912.html [PATCH] aarch64: Skip traditional GD/LD TLS which are unsupported by Clang and LLD [BZ #28205] can skip these tests if either CC or LD doesn't support traditional GD/LD.
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=33c50ef42878b07ee6ead8b3f1a81d8c2c74697c (elf: Drop elf/tls-macros.h in favor of __thread and tls_model attributes [BZ #28152] [BZ #28205]) Fixed for 2.35.