diff --git a/changelogs/unreleased/ghqa-321-segfault-with-clang-16-asan.md b/changelogs/unreleased/ghqa-321-segfault-with-clang-16-asan.md
new file mode 100644
index 0000000000000000000000000000000000000000..1d03d1588f3d2bde37e1f754030f4207f5e6a218
--- /dev/null
+++ b/changelogs/unreleased/ghqa-321-segfault-with-clang-16-asan.md
@@ -0,0 +1,5 @@
+## bugfix/core
+
+* Fixed a crash that could happen when Tarantool is compiled by `clang`
+ version 15 and above with enabled AddressSanitizer
+ (tarantool/tarantool-qa#321).
diff --git a/src/lib/core/fiber.c b/src/lib/core/fiber.c
index 0e281b49b2adaa17e5fda73a5c34ada652b6aa18..3694e0bbdcc72923a78a290def1f2724309f4d82 100644
--- a/src/lib/core/fiber.c
+++ b/src/lib/core/fiber.c
@@ -143,21 +143,27 @@ static int (*fiber_invoke)(fiber_func f, va_list ap);
#if ENABLE_ASAN
#include <sanitizer/asan_interface.h>
-#define ASAN_START_SWITCH_FIBER(var_name, will_switch_back, bottom, size) \
- void *var_name = NULL; \
- __sanitizer_start_switch_fiber((will_switch_back) ? &var_name : NULL, \
+#define ASAN_START_SWITCH_FIBER(fake_stack_save, will_switch_back, bottom, \
+ size) \
+ /* \
+ * When leaving a fiber definitely, NULL must be passed as the first \
+ * argument so that the fake stack is destroyed. \
+ */ \
+ void *fake_stack_save = NULL; \
+ __sanitizer_start_switch_fiber((will_switch_back) ? &fake_stack_save \
+ : NULL, \
(bottom), (size))
#if ASAN_INTERFACE_OLD
-#define ASAN_FINISH_SWITCH_FIBER(var_name) \
- __sanitizer_finish_switch_fiber(var_name);
+#define ASAN_FINISH_SWITCH_FIBER(fake_stack_save) \
+ __sanitizer_finish_switch_fiber(fake_stack_save)
#else
-#define ASAN_FINISH_SWITCH_FIBER(var_name) \
- __sanitizer_finish_switch_fiber(var_name, 0, 0);
+#define ASAN_FINISH_SWITCH_FIBER(fake_stack_save) \
+ __sanitizer_finish_switch_fiber(fake_stack_save, NULL, NULL)
#endif
#else
-#define ASAN_START_SWITCH_FIBER(var_name, will_switch_back, bottom, size)
-#define ASAN_FINISH_SWITCH_FIBER(var_name)
+#define ASAN_START_SWITCH_FIBER(fake_stack_save, will_switch_back, bottom, size)
+#define ASAN_FINISH_SWITCH_FIBER(fake_stack_save)
#endif
static inline int
@@ -396,6 +402,17 @@ cord_reset_slice(struct fiber *f)
cord()->slice = new_slice;
}
+/**
+ * True if a fiber with `fiber_flags` can be reused.
+ * A fiber can not be reused if it is somehow non-standard.
+ */
+static bool
+fiber_is_reusable(uint32_t fiber_flags)
+{
+ /* For now we can not reuse fibers with custom stack size. */
+ return (fiber_flags & FIBER_CUSTOM_STACK) == 0;
+}
+
/**
* Transfer control to callee fiber.
*/
@@ -678,12 +695,11 @@ fiber_join_timeout(struct fiber *fiber, double timeout)
}
/**
- * @note: this is not a cancellation point (@sa fiber_testcancel())
- * but it is considered good practice to call testcancel()
- * after each yield.
+ * Implementation of `fiber_yield()` and `fiber_yield_final()`.
+ * `will_switch_back` argument is used only by ASAN.
*/
-void
-fiber_yield(void)
+static void
+fiber_yield_impl(MAYBE_UNUSED bool will_switch_back)
{
struct cord *cord = cord();
struct fiber *caller = cord->fiber;
@@ -710,14 +726,28 @@ fiber_yield(void)
cord->fiber = callee;
callee->flags = (callee->flags & ~FIBER_IS_READY) | FIBER_IS_RUNNING;
- ASAN_START_SWITCH_FIBER(asan_state,
- (caller->flags & FIBER_IS_DEAD) == 0,
- callee->stack,
+ ASAN_START_SWITCH_FIBER(asan_state, will_switch_back, callee->stack,
callee->stack_size);
coro_transfer(&caller->ctx, &callee->ctx);
ASAN_FINISH_SWITCH_FIBER(asan_state);
}
+void
+fiber_yield(void)
+{
+ fiber_yield_impl(true);
+}
+
+/**
+ * Like `fiber_yield()`, but should be used when this is the last switch from
+ * a dead fiber to the scheduler.
+ */
+static void
+fiber_yield_final(void)
+{
+ fiber_yield_impl(false);
+}
+
struct fiber_watcher_data {
struct fiber *f;
bool timed_out;
@@ -882,7 +912,7 @@ fiber_reset(struct fiber *fiber)
clock_stat_reset(&fiber->clock_stat);
}
-/** Destroy an active fiber and prepare it for reuse. */
+/** Destroy an active fiber and prepare it for reuse or delete it. */
static void
fiber_recycle(struct fiber *fiber)
{
@@ -891,7 +921,6 @@ fiber_recycle(struct fiber *fiber)
assert(diag_is_empty(&fiber->diag));
/* no pending wakeup */
assert(rlist_empty(&fiber->state));
- bool has_custom_stack = fiber->flags & FIBER_CUSTOM_STACK;
fiber_stack_recycle(fiber);
fiber_reset(fiber);
fiber->name[0] = '\0';
@@ -910,7 +939,7 @@ fiber_recycle(struct fiber *fiber)
fiber->first_alloc_bt = NULL;
region_set_callbacks(&fiber->gc, NULL, NULL, NULL);
#endif
- if (!has_custom_stack) {
+ if (fiber_is_reusable(fiber->flags)) {
rlist_move_entry(&cord()->dead, fiber, link);
} else {
cord_add_garbage(cord(), fiber);
@@ -1037,7 +1066,14 @@ fiber_loop(MAYBE_UNUSED void *data)
* function again, ap is garbage by now.
*/
fiber->f = NULL;
- fiber_yield(); /* give control back to scheduler */
+ /*
+ * Give control back to the scheduler.
+ * If the fiber is not reusable, this is its final yield.
+ */
+ if (fiber_is_reusable(fiber->flags))
+ fiber_yield();
+ else
+ fiber_yield_final();
}
}
@@ -1330,13 +1366,10 @@ fiber_new_ex(const char *name, const struct fiber_attr *fiber_attr,
assert(fiber_attr != NULL);
cord_collect_garbage(cord);
- /* Now we can not reuse fiber if custom attribute was set */
- if (!(fiber_attr->flags & FIBER_CUSTOM_STACK) &&
- !rlist_empty(&cord->dead)) {
- fiber = rlist_first_entry(&cord->dead,
- struct fiber, link);
+ if (fiber_is_reusable(fiber_attr->flags) && !rlist_empty(&cord->dead)) {
+ fiber = rlist_first_entry(&cord->dead, struct fiber, link);
rlist_move_entry(&cord->alive, fiber, link);
- assert((fiber->flags | FIBER_IS_DEAD) != 0);
+ assert(fiber_is_dead(fiber));
} else {
fiber = (struct fiber *)
mempool_alloc(&cord->fiber_mempool);
diff --git a/src/lib/core/fiber.h b/src/lib/core/fiber.h
index 1b170c9fc0fb99f85664aaf3eae7df9def3c4704..1d6f0078b4e9f512567f183ac43bfdff5401061b 100644
--- a/src/lib/core/fiber.h
+++ b/src/lib/core/fiber.h
@@ -269,6 +269,9 @@ fiber_new_ex(const char *name, const struct fiber_attr *fiber_attr, fiber_func f
/**
* Return control to another fiber and wait until it'll be woken.
*
+ * \note this is not a cancellation point (\sa fiber_testcancel()), but it is
+ * considered a good practice to call fiber_testcancel() after each yield.
+ *
* \sa fiber_wakeup
*/
API_EXPORT void