From patchwork Fri Mar 22 15:44:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 10866135 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 549B0139A for ; Fri, 22 Mar 2019 15:47:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2F62B28E48 for ; Fri, 22 Mar 2019 15:47:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2383129182; Fri, 22 Mar 2019 15:47:29 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id AA1B52A8BD for ; Fri, 22 Mar 2019 15:47:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=r8x8TAVCPrPV4h/+5QiXTnw/0L5QC4+hOC/F7G9pfPk=; b=hnJXSviQB5739B vXT5yqe5UCqwfnVlc/N9s2vnSPT/hb2i2594/Rca4JCOV8yl3OhSqZYtiXcO+jKph0uCesMywmjgC 6GuLuCdUbLboJWe5+l9LAr1BJ+nuQegmHqUgIuBpnsO4WldBtK/YcqUSmPlfNKGE0bmUfK/MGsBv3 S5Sgjp9FQEQESjlwia9flnU43Ts7RBX58EcGVYlZ6QEA/Z0OocIQi6eqw+qTiXAq2WinVjERayIIA qSpbYjC8v7kZyysMcO8JXYcWnwsMP28q1mjIw6E8FPmQN9d3qOei6C+HAWlGFESfgzHipY9vE1Joh 8E74kzeyYgQ3nDASE+NQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h7MOF-0003lv-3L; Fri, 22 Mar 2019 15:47:27 +0000 Received: from mout.kundenserver.de ([212.227.17.10]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1h7MOA-0003Z0-SY for linux-arm-kernel@lists.infradead.org; Fri, 22 Mar 2019 15:47:24 +0000 Received: from wuerfel.lan ([149.172.19.189]) by mrelayeu.kundenserver.de (mreue108 [212.227.15.145]) with ESMTPA (Nemesis) id 1Mz9hF-1glrBT0Dlz-00wEbJ; Fri, 22 Mar 2019 16:46:56 +0100 From: Arnd Bergmann To: stable@vger.kernel.org, Catalin Marinas , Will Deacon , "Eric W. Biederman" , Mark Rutland , "Rafael J. Wysocki" , Anshuman Khandual , James Morse , Peter Maydell , Andrey Konovalov Subject: [BACKPORT 4.4.y 10/25] arm64: mm: Add trace_irqflags annotations to do_debug_exception() Date: Fri, 22 Mar 2019 16:44:01 +0100 Message-Id: <20190322154425.3852517-11-arnd@arndb.de> X-Mailer: git-send-email 2.20.0 In-Reply-To: <20190322154425.3852517-1-arnd@arndb.de> References: <20190322154425.3852517-1-arnd@arndb.de> MIME-Version: 1.0 X-Provags-ID: V03:K1:ZFpF8CAe8AmBwG8PGJWPFop0PRfjbeBIlad56HwVq67hsFHJ0tt /vTMl2X1z7FjJcfBD0yN8KM2IpfFg+j50kqftvc8+oe9L9ijCZIB96BSaGpzYkwAB3tKm5x QsQSsWeUgJ4gewKBKXcbAFOG+noCIE8Jlpu1KFR853UTVguO/qJWsuPHpuFMH4tfXZccPsR OKODfg19h+O9i3y9U71xQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:vhym0IdyrDA=:IagoDTjJ/AZm8MOUQihw/h lfjIfsiKuAjcr0YkJUa3nKwnT87irDoj13onxU3W5TDW0hf4b9zn9hX/tbM+y3Kd3QZY9nW4P ENXHg/s6eOeXdL/57nJ3gRv4nWemwtl58VGfkAJ/9GQRdeb4RZO3oaMPLSBP6XDcsIdZ+Idp4 jXvlvemWe6/NVlMZMALxF3//wuKh9mj0yT0WuAeKNOJ0BYycfiAxtLPnnJr8rJnw58QvCZ0ZF MK26TbIvudgq7V25j37GDFSAUKSfLEhsaFJEPlHPH0eO+OeycXf2dsU4DhLSVSXw59ibyHzwU SEni14uvrS8VhclQLU6h69oKllWXhaY2F+GpDcxxdxPb+KglXhXgMOFZO/IrrjUlZPzx0nDud cf6sj3qJA69QviQTQgygrApzKDiROW/IS1pABbOvyJoMLmyfP4b7ykMmYlWnorrgqwdh0+KSH OU3zPAxbKIWvkr2g+XuRnAa9d9lC005SfdyTJjBwS2PuBjfWJpNBRgISiNe82vigjFLRYl0gP m736lhhI/A7M2uTQBr/PhBhc+UsBteTXBV5ZG+7u/fx7jIRqNVOChl+BElMvlbSrgkbbVKIGq y86Da3naDGq/+sZryHTJZ143Z1/7CHhrrG7g00LrJ7pJoIu7jiyjVVUPIdQVv5LEgAW6HE20B Bjs4+SlMn0PTY8zvXnTC7v+YAPGsRnOWEKL1Y0kMjEc/X2G1vOMH91h1y3J+fc2lVvvHsiFT9 ccvN6lPlR10SMbWu8ROHz45cwbajO7eTSOlrjw== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190322_084723_229545_8BFE3CAA X-CRM114-Status: GOOD ( 15.80 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arm-kernel@lists.infradead.org, Arnd Bergmann , linux-kernel@vger.kernel.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: James Morse With CONFIG_PROVE_LOCKING, CONFIG_DEBUG_LOCKDEP and CONFIG_TRACE_IRQFLAGS enabled, lockdep will compare current->hardirqs_enabled with the flags from local_irq_save(). When a debug exception occurs, interrupts are disabled in entry.S, but lockdep isn't told, resulting in: DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled) ------------[ cut here ]------------ WARNING: at ../kernel/locking/lockdep.c:3523 Modules linked in: CPU: 3 PID: 1752 Comm: perf Not tainted 4.5.0-rc4+ #2204 Hardware name: ARM Juno development board (r1) (DT) task: ffffffc974868000 ti: ffffffc975f40000 task.ti: ffffffc975f40000 PC is at check_flags.part.35+0x17c/0x184 LR is at check_flags.part.35+0x17c/0x184 pc : [] lr : [] pstate: 600003c5 [...] ---[ end trace 74631f9305ef5020 ]--- Call trace: [] check_flags.part.35+0x17c/0x184 [] lock_acquire+0xa8/0xc4 [] breakpoint_handler+0x118/0x288 [] do_debug_exception+0x3c/0xa8 [] el1_dbg+0x18/0x6c [] do_filp_open+0x64/0xdc [] do_sys_open+0x140/0x204 [] SyS_openat+0x10/0x18 [] el0_svc_naked+0x24/0x28 possible reason: unannotated irqs-off. irq event stamp: 65857 hardirqs last enabled at (65857): [] lookup_mnt+0xf4/0x1b4 hardirqs last disabled at (65856): [] lookup_mnt+0xbc/0x1b4 softirqs last enabled at (65790): [] __do_softirq+0x1f8/0x290 softirqs last disabled at (65757): [] irq_exit+0x9c/0xd0 This patch adds the annotations to do_debug_exception(), while trying not to call trace_hardirqs_off() if el1_dbg() interrupted a task that already had irqs disabled. Signed-off-by: James Morse Signed-off-by: Will Deacon (cherry picked from commit 6afedcd23cfd7ac56c011069e4a8db37b46e4623) Signed-off-by: Arnd Bergmann --- arch/arm64/mm/fault.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index be7f8416809f..04c4b88706d8 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -595,20 +595,33 @@ asmlinkage int __exception do_debug_exception(unsigned long addr, { const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr); struct siginfo info; + int rv; - if (!inf->fn(addr, esr, regs)) - return 1; + /* + * Tell lockdep we disabled irqs in entry.S. Do nothing if they were + * already disabled to preserve the last enabled/disabled addresses. + */ + if (interrupts_enabled(regs)) + trace_hardirqs_off(); - pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n", - inf->name, esr, addr); + if (!inf->fn(addr, esr, regs)) { + rv = 1; + } else { + pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n", + inf->name, esr, addr); + + info.si_signo = inf->sig; + info.si_errno = 0; + info.si_code = inf->code; + info.si_addr = (void __user *)addr; + arm64_notify_die("", regs, &info, 0); + rv = 0; + } - info.si_signo = inf->sig; - info.si_errno = 0; - info.si_code = inf->code; - info.si_addr = (void __user *)addr; - arm64_notify_die("", regs, &info, 0); + if (interrupts_enabled(regs)) + trace_hardirqs_on(); - return 0; + return rv; } #ifdef CONFIG_ARM64_PAN