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| author | Stefan Hajnoczi <stefanha@redhat.com> | 2022-02-22 14:01:47 +0000 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2022-03-04 18:14:40 +0100 |
| commit | 7d29c341c9d402cf0bcb3a3b76fce0c09dd24e94 (patch) | |
| tree | 46d04234051c29163330e5bdb6e1015eca3133be /util/async.c | |
| parent | 11d0c9b37e94959662f6bcd640aa33137e11dcac (diff) | |
| download | focaccia-qemu-7d29c341c9d402cf0bcb3a3b76fce0c09dd24e94.tar.gz focaccia-qemu-7d29c341c9d402cf0bcb3a3b76fce0c09dd24e94.zip | |
tls: add macros for coroutine-safe TLS variables
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. The compiler can still optimize based on analyzing noinline code, so an asm volatile barrier with an output constraint is required to prevent unwanted optimizations. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1952483 Suggested-by: Serge Guelton <sguelton@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20220222140150.27240-2-stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'util/async.c')
0 files changed, 0 insertions, 0 deletions