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=-15.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 39CD1C433B4 for ; Fri, 16 Apr 2021 12:36:04 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 016806117A for ; Fri, 16 Apr 2021 12:36:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 016806117A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=kMj5TyyBCb2EzHB45R2vUCC/+A/tNUTrh9dB7Zjgb3A=; b=Cr6eq4B1E54adctCz02I0IQFm a5A/h9r2xQC3EnOsdRWPTl8nXKwLMBM/9Zti5AKpMQB3hfgo1kMhTHs4g8ypYE8mn0xohIrgGinKR GdttLtPDhhiVsoOCfOfbbTbH2kz769O0fqPpD8M7Gh2vKaBYX/lgaRl46uop1uEThwLQMIKD7FvDr 3qAZKIguJyhA9+xHZibfQG1b9YdfpXbwVPDQDQF8jqxC8a89rxdNIKikTsoMamsbt03+MNBClD1FC b3Zn/DySM/ykeDydW5/qGUvCzpXShACwIZYkBc9nnUUtaTHARDodeZtlLbA3Rc28Afu629lET2wPN J7ePxkUlg==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lXNfX-0025Cu-2G; Fri, 16 Apr 2021 12:33:55 +0000 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lXNf8-00259o-Is for linux-arm-kernel@desiato.infradead.org; Fri, 16 Apr 2021 12:33:31 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=CvLYpshOWyYfW7FDTUcK8sHghemyvXnkpswAS2OzTqI=; b=Vvh8RN5mHWcSg3vaJy9UifS4fo TRxZfrbpYEPCBrI2bOgafg3RHJNb5ARWF/PdlSlC+EzZWXp+m8uD0l8pNTfRpTihDkEVdk14187qs d+f0+uoLNgnmn+psA9NjwQjaTp9srOtl+yly1rZ8RXRiwx8Ug0EXFz3eR++AjfUaQdnM9eycL8rKn BkJuZCoi3rDRITPwI8I3nFYBVj1NnQQJNDPFWwGn9wAVIk695tAYkrL0XL+lyrzisD/2qMdjQp6UT c5iyTQJ+qmn6Q1HqDIqevU+Fwbp7uQf6+mD89l0kaXRzVlspAP12R6W5oZOF2toiIjmCEadcA3rY6 j0EYoO/g==; Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lXNf5-009MaZ-M9 for linux-arm-kernel@lists.infradead.org; Fri, 16 Apr 2021 12:33:29 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 67EF2610E6; Fri, 16 Apr 2021 12:33:25 +0000 (UTC) Date: Fri, 16 Apr 2021 13:33:22 +0100 From: Catalin Marinas To: He Zhe Cc: oleg@redhat.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, paul@paul-moore.com, eparis@redhat.com, linux-audit@redhat.com, linux-kernel@vger.kernel.org, Mark Rutland Subject: Re: [PATCH 1/3] arm64: ptrace: Add is_syscall_success to handle compat Message-ID: <20210416123322.GA23184@arm.com> References: <20210416075533.7720-1-zhe.he@windriver.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210416075533.7720-1-zhe.he@windriver.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210416_053327_789835_94BE3271 X-CRM114-Status: GOOD ( 20.71 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Apr 16, 2021 at 03:55:31PM +0800, He Zhe wrote: > The general version of is_syscall_success does not handle 32-bit > compatible case, which would cause 32-bit negative return code to be > recoganized as a positive number later and seen as a "success". > > Since is_compat_thread is defined in compat.h, implementing > is_syscall_success in ptrace.h would introduce build failure due to > recursive inclusion of some basic headers like mutex.h. We put the > implementation to ptrace.c > > Signed-off-by: He Zhe > --- > arch/arm64/include/asm/ptrace.h | 3 +++ > arch/arm64/kernel/ptrace.c | 10 ++++++++++ > 2 files changed, 13 insertions(+) > > diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h > index e58bca832dff..3c415e9e5d85 100644 > --- a/arch/arm64/include/asm/ptrace.h > +++ b/arch/arm64/include/asm/ptrace.h > @@ -328,6 +328,9 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) > regs->regs[0] = rc; > } > > +extern inline int is_syscall_success(struct pt_regs *regs); > +#define is_syscall_success(regs) is_syscall_success(regs) > + > /** > * regs_get_kernel_argument() - get Nth function argument in kernel > * @regs: pt_regs of that context > diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c > index 170f42fd6101..3266201f8c60 100644 > --- a/arch/arm64/kernel/ptrace.c > +++ b/arch/arm64/kernel/ptrace.c > @@ -1909,3 +1909,13 @@ int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task) > else > return valid_native_regs(regs); > } > + > +inline int is_syscall_success(struct pt_regs *regs) > +{ > + unsigned long val = regs->regs[0]; > + > + if (is_compat_thread(task_thread_info(current))) > + val = sign_extend64(val, 31); > + > + return !IS_ERR_VALUE(val); > +} It's better to use compat_user_mode(regs) here instead of is_compat_thread(). It saves us from worrying whether regs are for the current context. I think we should change regs_return_value() instead. This function seems to be called from several other places and it has the same potential problems if called on compat pt_regs. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel