On Mon, Oct 25, 2021 at 03:07:15PM +0100, Stefan Hajnoczi wrote: > Compiler optimizations can cache TLS values across coroutine yield > points, resulting in stale values from the previous thread when a > coroutine is re-entered by a new thread. > > Serge Guelton developed an __attribute__((noinline)) wrapper and tested > it with clang and gcc. I formatted his idea according to QEMU's coding > style and wrote documentation. > > These macros must be used instead of __thread from now on to prevent > coroutine TLS bugs.
Does this apply to all __thread usage in the QEMU process that can be used from coroutine context, or just certain __thread usage ? Mostly I'm wondering if this is going to have implications on external libraries we use. eg if block layer is using librbd.so APIs, is librbd.sp safe to use __thread directly in any way it desires ? Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
