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Re: TLS question
STT_TLS is not set for my extern __thread symbol.
and my linker ends up emitting:
TLS definition in /tmp/cccF5k6P.o section .tbss mismatches non-TLS
reference in /tmp/ccMzRAeS.o
What is responsible for setting this flag? the compiler? or it is set
while the elf is being read? I'm sure I have failed to implement
something in my port.
On Thu, 2012-03-22 at 14:53 -0400, Ian Lance Taylor wrote:
> Alireza Moshtaghi <email@example.com> writes:
> > An extern variable is defined as an UND symbol in the elf file, however,
> > when it is classified with __thread, the linker needs to match it up
> > with the correct definition from another object file.
> > The way that I have implemented TLS support in my port of binutils, the
> > linker complains that the extern symbol is not TLS and it can not link
> > it to the definition from the other object file.
> > The only thing that I can think of is to teach ld to look at the
> > relocation for that symbol and if it is a TLS relocation, it should be
> > able to match the two, but I don't know how to teach ld to do so.
> > Question is: where in the linker I must modify?
> An extern __thread variable should be SHN_UNDEF, STB_GLOBAL, STT_TLS.
> In other words, you don't have to look at relocations, you just have to
> look at the symbol type.