From owner-dev-commits-src-branches@freebsd.org Sat Feb 20 20:44:47 2021 Return-Path: Delivered-To: dev-commits-src-branches@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id EBCA1553DFD; Sat, 20 Feb 2021 20:44:47 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4DjgRg6M7Zz4hHH; Sat, 20 Feb 2021 20:44:47 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id CCFF425C69; Sat, 20 Feb 2021 20:44:47 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 11KKillY058495; Sat, 20 Feb 2021 20:44:47 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 11KKilel058494; Sat, 20 Feb 2021 20:44:47 GMT (envelope-from git) Date: Sat, 20 Feb 2021 20:44:47 GMT Message-Id: <202102202044.11KKilel058494@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Dimitry Andric Subject: git: 9418450e056f - stable/11 - Revert "Revert 3c4fd2463bb2 since upstream libcxxrt fixed it in another way" MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: dim X-Git-Repository: src X-Git-Refname: refs/heads/stable/11 X-Git-Reftype: branch X-Git-Commit: 9418450e056f8a75c0e5d0b1197d94745da0c18d Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-branches@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commits to the stable branches of the FreeBSD src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 20 Feb 2021 20:44:48 -0000 The branch stable/11 has been updated by dim: URL: https://cgit.FreeBSD.org/src/commit/?id=9418450e056f8a75c0e5d0b1197d94745da0c18d commit 9418450e056f8a75c0e5d0b1197d94745da0c18d Author: Dimitry Andric AuthorDate: 2021-02-20 20:41:13 +0000 Commit: Dimitry Andric CommitDate: 2021-02-20 20:41:13 +0000 Revert "Revert 3c4fd2463bb2 since upstream libcxxrt fixed it in another way" This reverts commit 49e7d3fee6ac52d1c65160a71b1f2be70e43c5e1, since I messed up and didn't merge the earlier libcxxrt changes first. --- contrib/libcxxrt/exception.cc | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-) diff --git a/contrib/libcxxrt/exception.cc b/contrib/libcxxrt/exception.cc index 0fb26ddb4ed2..0de878e9e6db 100644 --- a/contrib/libcxxrt/exception.cc +++ b/contrib/libcxxrt/exception.cc @@ -572,6 +572,19 @@ static void free_exception(char *e) } } +#ifdef __LP64__ +/** + * There's an ABI bug in __cxa_exception: unwindHeader requires 16-byte + * alignment but it was broken by the addition of the referenceCount. + * The unwindHeader is at offset 0x58 in __cxa_exception. In order to keep + * compatibility with consumers of the broken __cxa_exception, explicitly add + * padding on allocation (and account for it on free). + */ +static const int exception_alignment_padding = 8; +#else +static const int exception_alignment_padding = 0; +#endif + /** * Allocates an exception structure. Returns a pointer to the space that can * be used to store an object of thrown_size bytes. This function will use an @@ -580,16 +593,19 @@ static void free_exception(char *e) */ extern "C" void *__cxa_allocate_exception(size_t thrown_size) { - size_t size = thrown_size + sizeof(__cxa_exception); + size_t size = exception_alignment_padding + sizeof(__cxa_exception) + + thrown_size; char *buffer = alloc_or_die(size); - return buffer+sizeof(__cxa_exception); + return buffer + exception_alignment_padding + sizeof(__cxa_exception); } extern "C" void *__cxa_allocate_dependent_exception(void) { - size_t size = sizeof(__cxa_dependent_exception); + size_t size = exception_alignment_padding + + sizeof(__cxa_dependent_exception); char *buffer = alloc_or_die(size); - return buffer+sizeof(__cxa_dependent_exception); + return buffer + exception_alignment_padding + + sizeof(__cxa_dependent_exception); } /** @@ -617,7 +633,8 @@ extern "C" void __cxa_free_exception(void *thrown_exception) } } - free_exception(reinterpret_cast(ex)); + free_exception(reinterpret_cast(ex) - + exception_alignment_padding); } static void releaseException(__cxa_exception *exception) @@ -644,7 +661,8 @@ void __cxa_free_dependent_exception(void *thrown_exception) { releaseException(realExceptionFromException(reinterpret_cast<__cxa_exception*>(ex))); } - free_exception(reinterpret_cast(ex)); + free_exception(reinterpret_cast(ex) - + exception_alignment_padding); } /**