From d9945ccda08ef83b09ac7725b6ee2d1959f2c0c0 Mon Sep 17 00:00:00 2001 From: Akihiko Odaki Date: Wed, 17 Jan 2024 16:06:02 +0900 Subject: [PATCH] coroutine-ucontext: Save fake stack for pooled coroutine MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Coroutine may be pooled even after COROUTINE_TERMINATE if CONFIG_COROUTINE_POOL is enabled and fake stack should be saved in such a case to keep AddressSanitizerUseAfterReturn working. Even worse, I'm seeing stack corruption without fake stack being saved. Signed-off-by: Akihiko Odaki Reviewed-by: Marc-André Lureau Signed-off-by: Stefan Hajnoczi Message-ID: <20240117-asan-v2-1-26f9e1ea6e72@daynix.com> --- util/coroutine-ucontext.c | 35 ++++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 9 deletions(-) diff --git a/util/coroutine-ucontext.c b/util/coroutine-ucontext.c index 7b304c79d942..8ef603d081ea 100644 --- a/util/coroutine-ucontext.c +++ b/util/coroutine-ucontext.c @@ -119,13 +119,11 @@ void finish_switch_fiber(void *fake_stack_save) /* always_inline is required to avoid TSan runtime fatal errors. */ static inline __attribute__((always_inline)) -void start_switch_fiber_asan(CoroutineAction action, void **fake_stack_save, +void start_switch_fiber_asan(void **fake_stack_save, const void *bottom, size_t size) { #ifdef CONFIG_ASAN - __sanitizer_start_switch_fiber( - action == COROUTINE_TERMINATE ? NULL : fake_stack_save, - bottom, size); + __sanitizer_start_switch_fiber(fake_stack_save, bottom, size); #endif } @@ -165,7 +163,7 @@ static void coroutine_trampoline(int i0, int i1) if (!sigsetjmp(self->env, 0)) { CoroutineUContext *leaderp = get_ptr_leader(); - start_switch_fiber_asan(COROUTINE_YIELD, &fake_stack_save, + start_switch_fiber_asan(&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); @@ -226,8 +224,7 @@ Coroutine *qemu_coroutine_new(void) /* swapcontext() in, siglongjmp() back out */ if (!sigsetjmp(old_env, 0)) { - start_switch_fiber_asan(COROUTINE_YIELD, &fake_stack_save, co->stack, - co->stack_size); + start_switch_fiber_asan(&fake_stack_save, co->stack, co->stack_size); start_switch_fiber_tsan(&fake_stack_save, co, false); /* false=not caller */ @@ -269,10 +266,28 @@ static inline void valgrind_stack_deregister(CoroutineUContext *co) #endif #endif +#if defined(CONFIG_ASAN) && defined(CONFIG_COROUTINE_POOL) +static void coroutine_fn terminate_asan(void *opaque) +{ + CoroutineUContext *to = DO_UPCAST(CoroutineUContext, base, opaque); + + set_current(opaque); + start_switch_fiber_asan(NULL, to->stack, to->stack_size); + G_STATIC_ASSERT(!IS_ENABLED(CONFIG_TSAN)); + siglongjmp(to->env, COROUTINE_ENTER); +} +#endif + void qemu_coroutine_delete(Coroutine *co_) { CoroutineUContext *co = DO_UPCAST(CoroutineUContext, base, co_); +#if defined(CONFIG_ASAN) && defined(CONFIG_COROUTINE_POOL) + co_->entry_arg = qemu_coroutine_self(); + co_->entry = terminate_asan; + qemu_coroutine_switch(co_->entry_arg, co_, COROUTINE_ENTER); +#endif + #ifdef CONFIG_VALGRIND_H valgrind_stack_deregister(co); #endif @@ -305,8 +320,10 @@ qemu_coroutine_switch(Coroutine *from_, Coroutine *to_, ret = sigsetjmp(from->env, 0); if (ret == 0) { - start_switch_fiber_asan(action, &fake_stack_save, to->stack, - to->stack_size); + start_switch_fiber_asan(IS_ENABLED(CONFIG_COROUTINE_POOL) || + action != COROUTINE_TERMINATE ? + &fake_stack_save : NULL, + to->stack, to->stack_size); start_switch_fiber_tsan(&fake_stack_save, to, false); /* false=not caller */ siglongjmp(to->env, action);