From nobody Tue Oct 28 12:16:27 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1515082774824133.45128308619155; Thu, 4 Jan 2018 08:19:34 -0800 (PST) Received: from localhost ([::1]:47313 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eX8Ev-0002eV-Uv for importer@patchew.org; Thu, 04 Jan 2018 11:19:34 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38448) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eX855-0000pk-W0 for qemu-devel@nongnu.org; Thu, 04 Jan 2018 11:09:25 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eX852-0005gX-GY for qemu-devel@nongnu.org; Thu, 04 Jan 2018 11:09:23 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51095) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eX852-0005fn-8H for qemu-devel@nongnu.org; Thu, 04 Jan 2018 11:09:20 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7F72A5B2FD for ; Thu, 4 Jan 2018 16:09:19 +0000 (UTC) Received: from localhost (ovpn-112-61.ams2.redhat.com [10.36.112.61]) by smtp.corp.redhat.com (Postfix) with ESMTP id 304906017B; Thu, 4 Jan 2018 16:09:16 +0000 (UTC) From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= To: qemu-devel@nongnu.org Date: Thu, 4 Jan 2018 17:05:20 +0100 Message-Id: <20180104160523.22995-16-marcandre.lureau@redhat.com> In-Reply-To: <20180104160523.22995-1-marcandre.lureau@redhat.com> References: <20180104160523.22995-1-marcandre.lureau@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Thu, 04 Jan 2018 16:09:19 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v3 15/18] ucontext: annotate coroutine stack for ASAN X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , famz@redhat.com, Stefan Hajnoczi , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , pbonzini@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" It helps ASAN to detect more leaks on coroutine stacks, as found in the following patch. A similar work would need to be done for sigaltstack & windows fibers to have similar coverage. Since ucontext is preferred, I didn't bother checking the other coroutine implementations for now. Signed-off-by: Marc-Andr=C3=A9 Lureau Reviewed-by: Philippe Mathieu-Daud=C3=A9 Reviewed-by: Stefan Hajnoczi --- include/qemu/compiler.h | 4 ++++ util/coroutine-ucontext.c | 46 +++++++++++++++++++++++++++++++++++++++++++= +++ 2 files changed, 50 insertions(+) diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h index 340e5fdc09..5fcc4f7ec7 100644 --- a/include/qemu/compiler.h +++ b/include/qemu/compiler.h @@ -111,4 +111,8 @@ #define GCC_FMT_ATTR(n, m) #endif =20 +#ifndef __has_feature +#define __has_feature(x) 0 /* compatibility with non-clang compilers */ +#endif + #endif /* COMPILER_H */ diff --git a/util/coroutine-ucontext.c b/util/coroutine-ucontext.c index 6621f3f692..e78eae8766 100644 --- a/util/coroutine-ucontext.c +++ b/util/coroutine-ucontext.c @@ -31,6 +31,11 @@ #include #endif =20 +#if defined(__SANITIZE_ADDRESS__) || __has_feature(address_sanitizer) +#define CONFIG_ASAN 1 +#include +#endif + typedef struct { Coroutine base; void *stack; @@ -59,11 +64,37 @@ union cc_arg { int i[2]; }; =20 +static void finish_switch_fiber(void *fake_stack_save) +{ +#ifdef CONFIG_ASAN + const void *bottom_old; + size_t size_old; + + __sanitizer_finish_switch_fiber(fake_stack_save, &bottom_old, &size_ol= d); + + if (!leader.stack) { + leader.stack =3D (void *)bottom_old; + leader.stack_size =3D size_old; + } +#endif +} + +static void start_switch_fiber(void **fake_stack_save, + const void *bottom, size_t size) +{ +#ifdef CONFIG_ASAN + __sanitizer_start_switch_fiber(fake_stack_save, bottom, size); +#endif +} + static void coroutine_trampoline(int i0, int i1) { union cc_arg arg; CoroutineUContext *self; Coroutine *co; + void *fake_stack_save =3D NULL; + + finish_switch_fiber(NULL); =20 arg.i[0] =3D i0; arg.i[1] =3D i1; @@ -72,9 +103,13 @@ static void coroutine_trampoline(int i0, int i1) =20 /* Initialize longjmp environment and switch back the caller */ if (!sigsetjmp(self->env, 0)) { + start_switch_fiber(&fake_stack_save, + leader.stack, leader.stack_size); siglongjmp(*(sigjmp_buf *)co->entry_arg, 1); } =20 + finish_switch_fiber(fake_stack_save); + while (true) { co->entry(co->entry_arg); qemu_coroutine_switch(co, co->caller, COROUTINE_TERMINATE); @@ -87,6 +122,7 @@ Coroutine *qemu_coroutine_new(void) ucontext_t old_uc, uc; sigjmp_buf old_env; union cc_arg arg =3D {0}; + void *fake_stack_save =3D NULL; =20 /* The ucontext functions preserve signal masks which incurs a * system call overhead. sigsetjmp(buf, 0)/siglongjmp() does not @@ -122,8 +158,12 @@ Coroutine *qemu_coroutine_new(void) =20 /* swapcontext() in, siglongjmp() back out */ if (!sigsetjmp(old_env, 0)) { + start_switch_fiber(&fake_stack_save, co->stack, co->stack_size); swapcontext(&old_uc, &uc); } + + finish_switch_fiber(fake_stack_save); + return &co->base; } =20 @@ -169,13 +209,19 @@ qemu_coroutine_switch(Coroutine *from_, Coroutine *to= _, CoroutineUContext *from =3D DO_UPCAST(CoroutineUContext, base, from_); CoroutineUContext *to =3D DO_UPCAST(CoroutineUContext, base, to_); int ret; + void *fake_stack_save =3D NULL; =20 current =3D to_; =20 ret =3D sigsetjmp(from->env, 0); if (ret =3D=3D 0) { + start_switch_fiber(action =3D=3D COROUTINE_TERMINATE ? + NULL : &fake_stack_save, to->stack, to->stack_s= ize); siglongjmp(to->env, action); } + + finish_switch_fiber(fake_stack_save); + return ret; } =20 --=20 2.15.1.355.g36791d7216