From patchwork Fri Apr 3 20:31:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella X-Patchwork-Id: 38734 Return-Path: X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mail-qk1-x742.google.com (mail-qk1-x742.google.com [IPv6:2607:f8b0:4864:20::742]) by sourceware.org (Postfix) with ESMTPS id B8BB5388A02A for ; Fri, 3 Apr 2020 20:32:22 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org B8BB5388A02A Received: by mail-qk1-x742.google.com with SMTP id l25so1476041qkk.3 for ; Fri, 03 Apr 2020 13:32:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references; bh=Cslwsc5JnI7g5U5Ib8S1A0sHR50bg1P6k7zFmHgEkQ4=; b=U8TBx2kKWwW6d5c6otA0yCpJkwtTpHnlGufasRWeU7m1oLIhgwop8dMfOaIvQAbpDu j4lArjlUsRzISg4ZeElT1sn2nAQ3DPl6Gsv7SCutHHx1wXgkzysA9HcU1HrrcLb4wg0V cnid/vDgrYA/+b5Xzf8EVA09m7KT43IXSBRNPj//jrBq3NcOIzRzkt2yGt2Azr82dHIs wbuzkGbqlEO4XEikhYWcnllCzpnt9ic7DvOc9+oYGVVHPVhZj7l/o+BG/22Jm7DnDq2q 2JHyF4m/3/JnehqqlaVa6T1DZgGlcaBgGhYKOK0MKFynJ8qWSd6Q58C46Q48o1bfUYLS CS4g== X-Gm-Message-State: AGi0PuYmq+lFHlo0wktTupIexav9DNbQrw2FIAyDzmmkA0eQOl3iCQn/ qSqgS4n0I/eb0QKZfiF8unHu4y/qtf8= X-Google-Smtp-Source: APiQypKIQHe+vbE6pE6E83dcUgs6TVz8lD45kL/MqjhVU+sZU0bJYODtogKUXj7N9eM5f5h+zTu5+A== X-Received: by 2002:a37:ac0b:: with SMTP id e11mr10681996qkm.342.1585945942046; Fri, 03 Apr 2020 13:32:22 -0700 (PDT) Received: from localhost.localdomain ([177.194.48.209]) by smtp.googlemail.com with ESMTPSA id d141sm7063535qke.68.2020.04.03.13.32.20 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Apr 2020 13:32:21 -0700 (PDT) From: Adhemerval Zanella To: libc-alpha@sourceware.org Subject: [PATCH v4 09/21] nptl: arm: Fix Race conditions in pthread cancellation [BZ#12683] Date: Fri, 3 Apr 2020 17:31:49 -0300 Message-Id: <20200403203201.7494-10-adhemerval.zanella@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200403203201.7494-1-adhemerval.zanella@linaro.org> References: <20200403203201.7494-1-adhemerval.zanella@linaro.org> X-Spam-Status: No, score=-26.5 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_SHORT, RCVD_IN_DNSWL_NONE, 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-List-Received-Date: Fri, 03 Apr 2020 20:32:24 -0000 This patch adds the arm modifications required for the BZ#12683 fix by adding the arch-specific cancellation syscall bridge. Checked on arm-linux-gnueabihf. --- sysdeps/arm/nptl/tcb-offsets.sym | 3 + sysdeps/unix/sysv/linux/arm/syscall_cancel.S | 78 ++++++++++++++++++++ 2 files changed, 81 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/arm/syscall_cancel.S diff --git a/sysdeps/arm/nptl/tcb-offsets.sym b/sysdeps/arm/nptl/tcb-offsets.sym index bf9c0a1c17..c0e25630a2 100644 --- a/sysdeps/arm/nptl/tcb-offsets.sym +++ b/sysdeps/arm/nptl/tcb-offsets.sym @@ -8,3 +8,6 @@ MULTIPLE_THREADS_OFFSET thread_offsetof (header.multiple_threads) TID_OFFSET thread_offsetof (tid) + +-- Not strictly offsets, used on syscall_cancel.S +TCB_CANCELED_BITMASK CANCELED_BITMASK diff --git a/sysdeps/unix/sysv/linux/arm/syscall_cancel.S b/sysdeps/unix/sysv/linux/arm/syscall_cancel.S new file mode 100644 index 0000000000..3410bfc0f2 --- /dev/null +++ b/sysdeps/unix/sysv/linux/arm/syscall_cancel.S @@ -0,0 +1,78 @@ +/* Cancellable syscall wrapper. Linux/arm version. + Copyright (C) 2020 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 + +/* long int [r0] __syscall_cancel_arch (int *cancelhandling [r0], + long int nr [r1], + long int arg1 [r2], + long int arg2 [r3], + long int arg3 [SP], + long int arg4 [SP+4], + long int arg5 [SP+8], + long int arg6 [SP+12]) */ + + .syntax unified + +ENTRY (__syscall_cancel_arch) + .fnstart + mov ip, sp + stmfd sp!, {r4, r5, r6, r7, lr} + .save {r4, r5, r6, r7, lr} + + cfi_adjust_cfa_offset (20) + cfi_rel_offset (r4, 0) + cfi_rel_offset (r5, 4) + cfi_rel_offset (r6, 8) + cfi_rel_offset (r7, 12) + cfi_rel_offset (lr, 16) + + .globl __syscall_cancel_arch_start +__syscall_cancel_arch_start: + + /* if (*cancelhandling & CANCELED_BITMASK) + __syscall_do_cancel() */ + ldr r0, [r0] + tst r0, #TCB_CANCELED_BITMASK + bne 1f + + /* Issue a 6 argument syscall, the nr [r1] being the syscall + number. */ + mov r7, r1 + mov r0, r2 + mov r1, r3 + ldmfd ip, {r2, r3, r4, r5, r6} + svc 0x0 + + .globl __syscall_cancel_arch_end +__syscall_cancel_arch_end: + ldmfd sp!, {r4, r5, r6, r7, lr} + cfi_adjust_cfa_offset (-20) + cfi_restore (r4) + cfi_restore (r5) + cfi_restore (r6) + cfi_restore (r7) + cfi_restore (lr) + BX (lr) + +1: + ldmfd sp!, {r4, r5, r6, r7, lr} + b __syscall_do_cancel + .fnend +END (__syscall_cancel_arch) +libc_hidden_def (__syscall_cancel_arch)