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I checked and the .data.rel.ro section does indeed have the SHF_WRITE flag set. My understanding is that the section would need to be read-only and the SHF_MERGE flag would need to be set for the linker to try merging things. >> diff --git a/sysdeps/nptl/dl-tls_init_tp.c b/sysdeps/nptl/dl-tls_init_tp.c >> index 092c274f36..80eb0107b5 100644 >> --- a/sysdeps/nptl/dl-tls_init_tp.c >> +++ b/sysdeps/nptl/dl-tls_init_tp.c >> @@ -45,8 +45,10 @@ rtld_mutex_dummy (pthread_mutex_t *lock) >> #endif >> >> const unsigned int __rseq_flags; >> -const unsigned int __rseq_size attribute_relro; >> -const ptrdiff_t __rseq_offset attribute_relro; >> + >> +/* The variables are in .data.relro but are not yet write-protected. */ >> +extern unsigned int _rseq_size attribute_relro attribute_hidden; >> +extern ptrdiff_t _rseq_offset attribute_relro attribute_hidden; > > er, extern *and* hidden? And relro? > > In theory the relro one is harmless but meaningless, as externs don't > have sections in the local compilation unit. > > The hidden one will mark the symbol hidden, but does that really matter > as long as it's marked hidden where it's defined? Both attributes can be removed, the definition in the assembly file is what matters. I'll clean this in the next patch series.