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Date: Wed, 03 Feb 2021 08:16:30 +0100
From: Florian Weimer <>
To: Dominic Chen <>
Subject: Re: Incorrect thread TID caching

* Dominic Chen:

> From a quick skim of other libc implementations, both bionic and glibc
> don't seem to cache TID, and directly call the gettid system call
> inside raise().

Of course glibc has a TID cache.  It doesn't use it in raise (mostly to
get abort working after vfork), but it's definitely needed in other

If you use the clone system call wrapper in threading (not fork/vfork)
mode, you cannot call any libc functions afterwards, including the
syscall function.  Instead, you have to issue direct system calls.

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