From patchwork Wed Feb 17 16:03:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 42084 X-Patchwork-Delegate: carlos@redhat.com Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 063E03894428; Wed, 17 Feb 2021 16:03:05 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 063E03894428 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1613577785; bh=wkeq4UjxByvKdbIa54Y9UdliGjaGQa+cVpkSaw6Solo=; h=To:Subject:In-Reply-To:References:Date:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=NptPLLH77CMClLbyNdUoKGBc6Sc0V+bbIxfpHDMu92+34GuFcySulIiYaLbmTIBwR fPe8LDt0PTHLE2P8K3zOOTUGCwZHpBL2e7xZqI5fuHrtd62/GRok4wZ0CCzOndyzqZ JSsOj6ngh0l5yUzv80bAG7cEyR8Ilk7m0Tn9DiCw= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by sourceware.org (Postfix) with ESMTP id AE5243834416 for ; Wed, 17 Feb 2021 16:03:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org AE5243834416 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-599-47jVH0G0O6OJeBo5UzPSyA-1; Wed, 17 Feb 2021 11:02:59 -0500 X-MC-Unique: 47jVH0G0O6OJeBo5UzPSyA-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 A0EB71020C21 for ; Wed, 17 Feb 2021 16:02:58 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-113-131.ams2.redhat.com [10.36.113.131]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C658B19C47 for ; Wed, 17 Feb 2021 16:02:57 +0000 (UTC) To: libc-alpha@sourceware.org Subject: [PATCH 09/10] Implement _Unwind_Resume in libc on top of In-Reply-To: References: Message-Id: <0eb99b38cfa9be318413373f08da472caab51e52.1613577607.git.fweimer@redhat.com> Date: Wed, 17 Feb 2021 17:03:29 +0100 User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-12.4 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Florian Weimer via Libc-alpha From: Florian Weimer Reply-To: Florian Weimer Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" Temporarily move the arm _Unwind_Resume implementation to the file used by libpthread. It will be ported to along with the rest of nptl. Reviewed-by: Carlos O'Donell --- sysdeps/arm/arm-unwind-resume.S | 26 +++++++------- sysdeps/arm/pt-arm-unwind-resume.S | 48 ++++++++++++++++++++++++-- sysdeps/arm/unwind-arch.h | 4 +++ sysdeps/arm/unwind-resume.c | 25 ++++++++++++++ sysdeps/generic/unwind-resume.c | 55 +++++------------------------- 5 files changed, 97 insertions(+), 61 deletions(-) create mode 100644 sysdeps/arm/unwind-resume.c diff --git a/sysdeps/arm/arm-unwind-resume.S b/sysdeps/arm/arm-unwind-resume.S index 22525f4db0..92c171fe0f 100644 --- a/sysdeps/arm/arm-unwind-resume.S +++ b/sysdeps/arm/arm-unwind-resume.S @@ -18,29 +18,29 @@ #include -/* This is just implementing exactly what the C version does. +/* This is equivalent to the following C implementation: + + void + _Unwind_Resume (struct _Unwind_Exception *exc) + { + __unwind_link_get_resume () (exc); + } + We do it in assembly just to ensure that we get an unmolested tail call to the libgcc function, which is necessary for the ARM unwinder. */ ENTRY (_Unwind_Resume) - LDR_HIDDEN (ip, ip, __libgcc_s_resume, 0) - cmp ip, #0 - beq 1f -0: PTR_DEMANGLE (ip, ip, r2, r3) - bx ip - /* We need to save and restore LR (for our own return address) and R0 (for the argument to _Unwind_Resume) around the call. */ -1: push {r0, lr} + push {r0, lr} cfi_adjust_cfa_offset (8) cfi_rel_offset (r0, 0) cfi_rel_offset (lr, 4) - bl __libgcc_s_init + bl __unwind_link_get_resume + mov r3, r0 pop {r0, lr} cfi_adjust_cfa_offset (-8) - cfi_restore (r0) + cfi_restore (r4) cfi_restore (lr) - - LDR_HIDDEN (ip, ip, __libgcc_s_resume, 0) - b 0b + bx r3 END (_Unwind_Resume) diff --git a/sysdeps/arm/pt-arm-unwind-resume.S b/sysdeps/arm/pt-arm-unwind-resume.S index 7cb555c02b..d579848696 100644 --- a/sysdeps/arm/pt-arm-unwind-resume.S +++ b/sysdeps/arm/pt-arm-unwind-resume.S @@ -1,2 +1,46 @@ -#define __libgcc_s_init pthread_cancel_init -#include +/* _Unwind_Resume wrapper for ARM EABI. + Copyright (C) 2015-2021 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + . */ + +#include + +/* This is just implementing exactly what the C version does. + We do it in assembly just to ensure that we get an unmolested tail + call to the libgcc function, which is necessary for the ARM unwinder. */ + +ENTRY (_Unwind_Resume) + LDR_HIDDEN (ip, ip, __libgcc_s_resume, 0) + cmp ip, #0 + beq 1f +0: PTR_DEMANGLE (ip, ip, r2, r3) + bx ip + + /* We need to save and restore LR (for our own return address) + and R0 (for the argument to _Unwind_Resume) around the call. */ +1: push {r0, lr} + cfi_adjust_cfa_offset (8) + cfi_rel_offset (r0, 0) + cfi_rel_offset (lr, 4) + bl pthread_cancel_init + pop {r0, lr} + cfi_adjust_cfa_offset (-8) + cfi_restore (r0) + cfi_restore (lr) + + LDR_HIDDEN (ip, ip, __libgcc_s_resume, 0) + b 0b +END (_Unwind_Resume) diff --git a/sysdeps/arm/unwind-arch.h b/sysdeps/arm/unwind-arch.h index fcf889b3c7..62f643b221 100644 --- a/sysdeps/arm/unwind-arch.h +++ b/sysdeps/arm/unwind-arch.h @@ -32,4 +32,8 @@ assert (local.ptr__Unwind_VRS_Get != NULL); \ PTR_MANGLE (local.ptr__Unwind_VRS_Get); +/* This is used by the _Unwind_Resume assembler implementation to + obtain the address to jump to. */ +void *__unwind_link_get_resume (void) attribute_hidden; + #endif /* _ARCH_UNWIND_LINK_H */ diff --git a/sysdeps/arm/unwind-resume.c b/sysdeps/arm/unwind-resume.c new file mode 100644 index 0000000000..169d5c30e6 --- /dev/null +++ b/sysdeps/arm/unwind-resume.c @@ -0,0 +1,25 @@ +/* Unwinder function forwarders for libc. Arm version. + Copyright (C) 2021 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; see the file COPYING.LIB. If + not, see . */ + +#include + +void * +__unwind_link_get_resume (void) +{ + return UNWIND_LINK_PTR (link (), _Unwind_Resume); +} diff --git a/sysdeps/generic/unwind-resume.c b/sysdeps/generic/unwind-resume.c index 09533d6992..9e63762bf1 100644 --- a/sysdeps/generic/unwind-resume.c +++ b/sysdeps/generic/unwind-resume.c @@ -16,68 +16,31 @@ License along with the GNU C Library; see the file COPYING.LIB. If not, see . */ -#include #include -#include #include +#include #include #include - -void (*__libgcc_s_resume) (struct _Unwind_Exception *exc) - attribute_hidden __attribute__ ((noreturn)); - -static _Unwind_Reason_Code (*libgcc_s_personality) PERSONALITY_PROTO; - -void attribute_hidden __attribute__ ((cold)) -__libgcc_s_init (void) +static struct unwind_link * +link (void) { - void *resume, *personality; - void *handle; - - /* See include/dlfcn.h. Use of __libc_dlopen requires RTLD_NOW. */ - handle = __libc_dlopen (LIBGCC_S_SO); - - if (handle == NULL - || (resume = __libc_dlsym (handle, "_Unwind_Resume")) == NULL - || (personality = __libc_dlsym (handle, "__gcc_personality_v0")) == NULL) - __libc_fatal (LIBGCC_S_SO - " must be installed for unwinding to work\n"); - -#ifdef PTR_MANGLE - PTR_MANGLE (resume); -#endif - __libgcc_s_resume = resume; -#ifdef PTR_MANGLE - PTR_MANGLE (personality); -#endif - libgcc_s_personality = personality; + struct unwind_link *unwind_link = __libc_unwind_link_get (); + if (unwind_link == NULL) + __libc_fatal (LIBGCC_S_SO " must be installed for unwinding to work\n"); + return unwind_link; } #if !HAVE_ARCH_UNWIND_RESUME void _Unwind_Resume (struct _Unwind_Exception *exc) { - if (__glibc_unlikely (__libgcc_s_resume == NULL)) - __libgcc_s_init (); - - __typeof (__libgcc_s_resume) resume = __libgcc_s_resume; -#ifdef PTR_DEMANGLE - PTR_DEMANGLE (resume); -#endif - (*resume) (exc); + UNWIND_LINK_PTR (link (), _Unwind_Resume) (exc); } #endif _Unwind_Reason_Code __gcc_personality_v0 PERSONALITY_PROTO { - if (__glibc_unlikely (libgcc_s_personality == NULL)) - __libgcc_s_init (); - - __typeof (libgcc_s_personality) personality = libgcc_s_personality; -#ifdef PTR_DEMANGLE - PTR_DEMANGLE (personality); -#endif - return (*personality) PERSONALITY_ARGS; + return UNWIND_LINK_PTR (link (), personality) PERSONALITY_ARGS; }