From patchwork Mon Dec 11 19:06:50 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella Netto X-Patchwork-Id: 24863 Received: (qmail 41213 invoked by alias); 11 Dec 2017 19:07:23 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 41188 invoked by uid 89); 11 Dec 2017 19:07:22 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-25.8 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mail-qt0-f194.google.com 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=dDx1LeN6LkMETtkjqt/IYdk5RljfTjHXK3uQHILN+Ec=; b=dWY3ff3p8V2rUEGWX+ywgfEUUXf5y6O9Ag1124fAA5Z3+9oP5L1Mi/LJMDHx7Vx/2U LF91VwX/pBolq0PCPyN7Y957M+X1Xp/PH0TBpV/Svifh5c+/5aNLGSO0m2DOLtb4OJXU I/SrUriSnUBaWA84IE+RS3+yNaAIbh7a0wv24VsMNUh1JHprT7K8EmqzpFelR6zmr+ek 5ru7EG7tkKQKUNu1SGOMQlQ1MjlvKurXUBUlyEv/mQoqDN1G5WSJ3zyfnATfp7KeLJy3 2ZjX7LqyFLftNZ/m+bpzI/rKXdGhAT7pVUI9aHok1KKo5d22yEcLITRxVSovTNjUDj1e snAg== X-Gm-Message-State: AKGB3mKSeoWUn0NDvdiAJcg5PBZUxx+jWNWFAK106y/nKrxU7VEOTXP7 6mP+S3ldOb+qd80ILG0Jvc+HHY3zp3w= X-Google-Smtp-Source: ACJfBovI+eKBbkOmjDQwt+EFtlyEVKdOxE9c8V0JvyVZCfuvS5LiwekFoAkdfPnlPdHWMEdVjV5fxQ== X-Received: by 10.55.182.129 with SMTP id g123mr1825499qkf.243.1513019239376; Mon, 11 Dec 2017 11:07:19 -0800 (PST) From: Adhemerval Zanella To: libc-alpha@sourceware.org Subject: [PATCH 06/19] nptl: powerpc: Fix Race conditions in pthread cancellation (BZ#12683) Date: Mon, 11 Dec 2017 17:06:50 -0200 Message-Id: <1513019223-7603-7-git-send-email-adhemerval.zanella@linaro.org> In-Reply-To: <1513019223-7603-1-git-send-email-adhemerval.zanella@linaro.org> References: <1513019223-7603-1-git-send-email-adhemerval.zanella@linaro.org> This patches adds the powerpc64 modification required for the BZ#12683. It basically adds the required __pthread_get_pc function and a arch specific syscall_cancel implementation. The powerpc requires an arch-specific syscall_cancel because INTERNAL_SYSCALL_NCS adds a mfcr just after the sc instruction to get the CR0.SO bit information from kernel (which signals the error return status). So for cancelled syscalls with side effects, __pthread_get_pc will point to mcfr and thus invalidating the checks on sigcancel_handler. Checked on powerpc64le-linux-gnu and powerpc-linux-gnu. * sysdeps/unix/sysv/linux/powerpc/syscall_cancel.S: New file. * sysdeps/unix/sysv/linux/powerpc/sysdep-cancel.h (__pthread_get_pc): New function. Signed-off-by: Adhemerval Zanella --- ChangeLog | 4 ++ sysdeps/unix/sysv/linux/powerpc/sigcontextinfo.h | 16 ++++++ sysdeps/unix/sysv/linux/powerpc/syscall_cancel.S | 64 ++++++++++++++++++++++++ 3 files changed, 84 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/powerpc/syscall_cancel.S diff --git a/sysdeps/unix/sysv/linux/powerpc/sigcontextinfo.h b/sysdeps/unix/sysv/linux/powerpc/sigcontextinfo.h index b8b5997..aada838 100644 --- a/sysdeps/unix/sysv/linux/powerpc/sigcontextinfo.h +++ b/sysdeps/unix/sysv/linux/powerpc/sigcontextinfo.h @@ -15,7 +15,11 @@ License along with the GNU C Library; if not, see . */ +#ifndef _SIGCONTEXTINFO_H +#define _SIGCONTEXTINFO_H + #include +#include #define SIGCONTEXT struct sigcontext * #define SIGCONTEXT_EXTRA_ARGS @@ -24,3 +28,15 @@ #define GET_STACK(ctx) ((void *)((ctx)->regs->gpr[1])) #define CALL_SIGHANDLER(handler, signo, ctx) \ (handler)((signo), SIGCONTEXT_EXTRA_ARGS (ctx)) + +static inline uintptr_t +ucontext_get_pc (const ucontext_t *uc) +{ +#ifdef __powerpc64__ + return uc->uc_mcontext.gp_regs[PT_NIP]; +#else + return uc->uc_mcontext.uc_regs->gregs[PT_NIP]; +#endif +} + +#endif /* _SIGCONTEXTINFO_H */ diff --git a/sysdeps/unix/sysv/linux/powerpc/syscall_cancel.S b/sysdeps/unix/sysv/linux/powerpc/syscall_cancel.S new file mode 100644 index 0000000..bda2199 --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/syscall_cancel.S @@ -0,0 +1,64 @@ +/* Cancellable syscall wrapper. Linux/powerpc version. + Copyright (C) 2017 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 [r3] __syscall_cancel_arch (int *cancelhandling [r3], + long int nr [r4], + long int arg1 [r5], + long int arg2 [r6], + long int arg3 [r7], + long int arg4 [r8], + long int arg5 [r9], + long int arg6 [r10]) */ + +ENTRY (__syscall_cancel_arch) + + .globl __syscall_cancel_arch_start + .type __syscall_cancel_arch_start,@function +__syscall_cancel_arch_start: + + /* if (*cancelhandling & CANCELED_BITMASK) + __syscall_do_cancel() */ + lwz r0,0(r3) + rldicl. r0,r0,62,63 + beq 1f + b __syscall_do_cancel + nop +1: + /* Issue a 6 argument syscall, the nr [r4] being the syscall + number. */ + mr r0,r4 + mr r3,r5 + mr r4,r6 + mr r5,r7 + mr r6,r8 + mr r7,r9 + mr r8,r10 + ABORT_TRANSACTION + sc + + .globl __syscall_cancel_arch_end + .type __syscall_cancel_arch_end,@function +__syscall_cancel_arch_end: + + bnslr+ + neg r3,r3 + blr +END (__syscall_cancel_arch) +libc_hidden_def (__syscall_cancel_arch)