From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 708CDC433F5 for ; Mon, 7 Mar 2022 15:52:56 +0000 (UTC) Received: from localhost ([::1]:58282 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nRFfL-00022I-J5 for qemu-devel@archiver.kernel.org; Mon, 07 Mar 2022 10:52:55 -0500 Received: from eggs.gnu.org ([209.51.188.92]:40560) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nRFSB-0000v9-6K for qemu-devel@nongnu.org; Mon, 07 Mar 2022 10:39:19 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:28821) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nRFS9-0004Cb-5T for qemu-devel@nongnu.org; Mon, 07 Mar 2022 10:39:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646667556; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=w0lwfbgakbDPz2F1Wm8I8jfyO4wDR1n9q2xO5avVkiI=; b=WOYUYLL5rJeOYJcRRXERCIUFxa/LBJxlH7j3axem5lbFFlnnrR/wu4e1UeamjQ+JjX2mmo QGc6UO5MMWxlpTjNIR32fkHJcV8A62Y6LFrmf0em0RruzQA+oGeZYefceURjOpE481zO7E +IXRN0itcQb6B3kmGeu13eMfmPYFTAg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-609-0F83zgenPTSO_wkMvPDUfg-1; Mon, 07 Mar 2022 10:39:13 -0500 X-MC-Unique: 0F83zgenPTSO_wkMvPDUfg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9BDD11006AA8; Mon, 7 Mar 2022 15:39:12 +0000 (UTC) Received: from localhost (unknown [10.39.193.253]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9E48C26343; Mon, 7 Mar 2022 15:39:07 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Subject: [PATCH 1/3] coroutine-ucontext: use QEMU_DEFINE_STATIC_CO_TLS() Date: Mon, 7 Mar 2022 15:38:51 +0000 Message-Id: <20220307153853.602859-2-stefanha@redhat.com> In-Reply-To: <20220307153853.602859-1-stefanha@redhat.com> References: <20220307153853.602859-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=stefanha@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, Stefan Weil , Stefan Hajnoczi Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 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 --- 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 #include "qemu/coroutine_int.h" +#include "qemu/coroutine-tls.h" #ifdef CONFIG_VALGRIND_H #include @@ -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; } -- 2.35.1