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Re: [PATCH] Async signal safe TLS accesses


On Thu, Jan 2, 2014 at 11:45 PM, Rich Felker <dalias@aerifal.cx> wrote:
> No, you can't; you cannot prove that the application did not already
> save the address of a thread-local object for later usage. If it did,
> moving the object to a different address would be illegal.
>
> Rich

Oh yeah, duh.  So it's not just a terrible idea, it also just doesn't work.

In practice, I *believe* this exclusively happens in the case I
detailed far upthread (where one object makes a reference to an extern
TLS variable as init-exec) which is fairly contrived and I'm not too
worried about the fact that it's unreliable.  And I don't believe this
patch actually changes the behavior there, anyway.


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