+++ /dev/null
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Stefan Hajnoczi <stefanha@redhat.com>
-Date: Mon, 7 Mar 2022 15:38:51 +0000
-Subject: [PATCH] coroutine-ucontext: use QEMU_DEFINE_STATIC_CO_TLS()
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-Thread-Local Storage variables cannot be used directly from coroutine
-code because the compiler may optimize TLS variable accesses across
-qemu_coroutine_yield() calls. When the coroutine is re-entered from
-another thread the TLS variables from the old thread must no longer be
-used.
-
-Use QEMU_DEFINE_STATIC_CO_TLS() for the current and leader variables.
-
-Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-Message-Id: <20220307153853.602859-2-stefanha@redhat.com>
-Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
-Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-(cherry-picked from commit 34145a307d849d0b6734d0222a7aa0bb9eef7407)
-Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
----
- util/coroutine-ucontext.c | 38 ++++++++++++++++++++++++--------------
- 1 file changed, 24 insertions(+), 14 deletions(-)
-
-diff --git a/util/coroutine-ucontext.c b/util/coroutine-ucontext.c
-index 904b375192..127d5a13c8 100644
---- a/util/coroutine-ucontext.c
-+++ b/util/coroutine-ucontext.c
-@@ -25,6 +25,7 @@
- #include "qemu/osdep.h"
- #include <ucontext.h>
- #include "qemu/coroutine_int.h"
-+#include "qemu/coroutine-tls.h"
-
- #ifdef CONFIG_VALGRIND_H
- #include <valgrind/valgrind.h>
-@@ -66,8 +67,8 @@ typedef struct {
- /**
- * Per-thread coroutine bookkeeping
- */
--static __thread CoroutineUContext leader;
--static __thread Coroutine *current;
-+QEMU_DEFINE_STATIC_CO_TLS(Coroutine *, current);
-+QEMU_DEFINE_STATIC_CO_TLS(CoroutineUContext, leader);
-
- /*
- * va_args to makecontext() must be type 'int', so passing
-@@ -97,14 +98,15 @@ static inline __attribute__((always_inline))
- void finish_switch_fiber(void *fake_stack_save)
- {
- #ifdef CONFIG_ASAN
-+ CoroutineUContext *leaderp = get_ptr_leader();
- const void *bottom_old;
- size_t size_old;
-
- __sanitizer_finish_switch_fiber(fake_stack_save, &bottom_old, &size_old);
-
-- if (!leader.stack) {
-- leader.stack = (void *)bottom_old;
-- leader.stack_size = size_old;
-+ if (!leaderp->stack) {
-+ leaderp->stack = (void *)bottom_old;
-+ leaderp->stack_size = size_old;
- }
- #endif
- #ifdef CONFIG_TSAN
-@@ -161,8 +163,10 @@ static void coroutine_trampoline(int i0, int i1)
-
- /* Initialize longjmp environment and switch back the caller */
- if (!sigsetjmp(self->env, 0)) {
-- start_switch_fiber_asan(COROUTINE_YIELD, &fake_stack_save, leader.stack,
-- leader.stack_size);
-+ CoroutineUContext *leaderp = get_ptr_leader();
-+
-+ start_switch_fiber_asan(COROUTINE_YIELD, &fake_stack_save,
-+ leaderp->stack, leaderp->stack_size);
- start_switch_fiber_tsan(&fake_stack_save, self, true); /* true=caller */
- siglongjmp(*(sigjmp_buf *)co->entry_arg, 1);
- }
-@@ -297,7 +301,7 @@ qemu_coroutine_switch(Coroutine *from_, Coroutine *to_,
- int ret;
- void *fake_stack_save = NULL;
-
-- current = to_;
-+ set_current(to_);
-
- ret = sigsetjmp(from->env, 0);
- if (ret == 0) {
-@@ -315,18 +319,24 @@ qemu_coroutine_switch(Coroutine *from_, Coroutine *to_,
-
- Coroutine *qemu_coroutine_self(void)
- {
-- if (!current) {
-- current = &leader.base;
-+ Coroutine *self = get_current();
-+ CoroutineUContext *leaderp = get_ptr_leader();
-+
-+ if (!self) {
-+ self = &leaderp->base;
-+ set_current(self);
- }
- #ifdef CONFIG_TSAN
-- if (!leader.tsan_co_fiber) {
-- leader.tsan_co_fiber = __tsan_get_current_fiber();
-+ if (!leaderp->tsan_co_fiber) {
-+ leaderp->tsan_co_fiber = __tsan_get_current_fiber();
- }
- #endif
-- return current;
-+ return self;
- }
-
- bool qemu_in_coroutine(void)
- {
-- return current && current->caller;
-+ Coroutine *self = get_current();
-+
-+ return self && self->caller;
- }