From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE446C07E85 for ; Fri, 7 Dec 2018 15:58:07 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3917420673 for ; Fri, 7 Dec 2018 15:58:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3917420673 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=altlinux.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 43BHDr51bbzDr2P for ; Sat, 8 Dec 2018 02:58:04 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=altlinux.org Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=altlinux.org (client-ip=194.107.17.57; helo=vmicros1.altlinux.org; envelope-from=ldv@altlinux.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=altlinux.org Received: from vmicros1.altlinux.org (vmicros1.altlinux.org [194.107.17.57]) by lists.ozlabs.org (Postfix) with ESMTP id 43BHBb49zgzDrqd for ; Sat, 8 Dec 2018 02:56:07 +1100 (AEDT) Received: from mua.local.altlinux.org (mua.local.altlinux.org [192.168.1.14]) by vmicros1.altlinux.org (Postfix) with ESMTP id 0952672CC59; Fri, 7 Dec 2018 18:56:06 +0300 (MSK) Received: by mua.local.altlinux.org (Postfix, from userid 508) id EB8CE7CE9F4; Fri, 7 Dec 2018 18:56:05 +0300 (MSK) Date: Fri, 7 Dec 2018 18:56:05 +0300 From: "Dmitry V. Levin" To: Michael Ellerman Subject: [PATCH v5] powerpc/ptrace: replace ptrace_report_syscall() with a tracehook call Message-ID: <20181207155605.GB28964@altlinux.org> References: <20181116121701.14359da0@akathisia> <87ftw12nyn.fsf@concordia.ellerman.id.au> <20181119210139.GA8360@altlinux.org> <87efbe166y.fsf@concordia.ellerman.id.au> <20181203031823.GE11573@altlinux.org> <20181207011946.GA18558@altlinux.org> <87y391k2tq.fsf@concordia.ellerman.id.au> <20181207154255.GA28964@altlinux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181207154255.GA28964@altlinux.org> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Oleg Nesterov , Eugene Syromyatnikov , Elvira Khabirova , Paul Mackerras , Andy Lutomirski , Breno Leitao , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Elvira Khabirova Arch code should use tracehook_*() helpers, as documented in include/linux/tracehook.h, ptrace_report_syscall() is not expected to be used outside that file. The patch does not look very nice, but at least it is correct and opens the way for PTRACE_GET_SYSCALL_INFO API. Co-authored-by: Dmitry V. Levin Fixes: 5521eb4bca2d ("powerpc/ptrace: Add support for PTRACE_SYSEMU") Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Oleg Nesterov Cc: Breno Leitao Cc: Andy Lutomirski Cc: Eugene Syromyatnikov Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Elvira Khabirova Signed-off-by: Dmitry V. Levin --- v5: reverted to a simple approach, compile- and run-tested v4: rewritten to call tracehook_report_syscall_entry() once, compile-tested v3: add a descriptive comment v2: explicitly ignore tracehook_report_syscall_entry() return code arch/powerpc/kernel/ptrace.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index afb819f4ca68..714c3480c52d 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -3266,12 +3266,17 @@ long do_syscall_trace_enter(struct pt_regs *regs) user_exit(); if (test_thread_flag(TIF_SYSCALL_EMU)) { - ptrace_report_syscall(regs); /* + * A nonzero return code from tracehook_report_syscall_entry() + * tells us to prevent the syscall execution, but we are not + * going to execute it anyway. + * * Returning -1 will skip the syscall execution. We want to * avoid clobbering any register also, thus, not 'gotoing' * skip label. */ + if (tracehook_report_syscall_entry(regs)) + ; return -1; } -- ldv