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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 8E959C10F29 for ; Mon, 9 Mar 2020 16:59:57 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 586B920727 for ; Mon, 9 Mar 2020 16:59:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Pjh7S3QN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 586B920727 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject: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=tc5nKENGiimas8QrB4cyeOtjisxYVs95MZNB7CHC4dQ=; b=Pjh7S3QNw9VFge q3YHSPSF20DKzGopWpgbBKE9sJAwWbhPqWdrPyyENVP7MmeUf9jTKnBZ+669BOnIqlqFGazH4brIl Ct2Ezbd+ZSukAMAwhecLuvo+0CSYEjQp9N47sD5Rwgs4qlFFb+OpeKIyNqPZXCvw3udm6UIReVKXO naO+a2KWF6rAip1AK2oFk4NdZ81t3oJDvx+YRbTw+GbXagW+ftAslGthvML5oHf6Lg9vza55d+rAU lF9oignTPl1t4uUEgT1cxXPMPsLRwEVwmNliMx3ZDmt1rGOroEYtVO0Edk5cT8DY0h5pbizXVxFtB QomRzM0RJ+siWM4TJR0g==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jBLkv-0002w6-TS; Mon, 09 Mar 2020 16:59:53 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jBLks-0002vL-TO for linux-arm-kernel@lists.infradead.org; Mon, 09 Mar 2020 16:59:52 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 020081FB; Mon, 9 Mar 2020 09:59:50 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1926E3F534; Mon, 9 Mar 2020 09:59:47 -0700 (PDT) Date: Mon, 9 Mar 2020 16:59:46 +0000 From: Mark Rutland To: Alex Belits Subject: Re: [PATCH v2 06/12] task_isolation: arch/arm64: enable task isolation functionality Message-ID: <20200309165945.GB44566@lakrids.cambridge.arm.com> References: <4473787e1b6bc3cc226067e8d122092a678b63de.camel@marvell.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200309_095951_034964_1BBC1FBA X-CRM114-Status: GOOD ( 26.93 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "linux-arch@vger.kernel.org" , "catalin.marinas@arm.com" , "peterz@infradead.org" , Prasun Kapoor , "frederic@kernel.org" , "linux-kernel@vger.kernel.org" , "rostedt@goodmis.org" , "davem@davemloft.net" , "netdev@vger.kernel.org" , "linux-api@vger.kernel.org" , "tglx@linutronix.de" , "will@kernel.org" , "mingo@kernel.org" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sun, Mar 08, 2020 at 03:50:58AM +0000, Alex Belits wrote: > From: Chris Metcalf > > In do_notify_resume(), call task_isolation_start() for > TIF_TASK_ISOLATION tasks. Add _TIF_TASK_ISOLATION to _TIF_WORK_MASK, > and define a local NOTIFY_RESUME_LOOP_FLAGS to check in the loop, > since we don't clear _TIF_TASK_ISOLATION in the loop. > > We instrument the smp_send_reschedule() routine so that it checks for > isolated tasks and generates a suitable warning if needed. > > Finally, report on page faults in task-isolation processes in > do_page_faults(). > > Signed-off-by: Chris Metcalf > [abelits@marvell.com: simplified to match kernel 5.6] > Signed-off-by: Alex Belits > --- > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/thread_info.h | 5 ++++- > arch/arm64/kernel/ptrace.c | 10 ++++++++++ > arch/arm64/kernel/signal.c | 13 ++++++++++++- > arch/arm64/kernel/smp.c | 7 +++++++ > arch/arm64/mm/fault.c | 5 +++++ > 6 files changed, 39 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 0b30e884e088..93b6aabc8be9 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -129,6 +129,7 @@ config ARM64 > select HAVE_ARCH_PREL32_RELOCATIONS > select HAVE_ARCH_SECCOMP_FILTER > select HAVE_ARCH_STACKLEAK > + select HAVE_ARCH_TASK_ISOLATION > select HAVE_ARCH_THREAD_STRUCT_WHITELIST > select HAVE_ARCH_TRACEHOOK > select HAVE_ARCH_TRANSPARENT_HUGEPAGE > diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h > index f0cec4160136..7563098eb5b2 100644 > --- a/arch/arm64/include/asm/thread_info.h > +++ b/arch/arm64/include/asm/thread_info.h > @@ -63,6 +63,7 @@ void arch_release_task_struct(struct task_struct *tsk); > #define TIF_FOREIGN_FPSTATE 3 /* CPU's FP state is not current's */ > #define TIF_UPROBE 4 /* uprobe breakpoint or singlestep */ > #define TIF_FSCHECK 5 /* Check FS is USER_DS on return */ > +#define TIF_TASK_ISOLATION 6 > #define TIF_NOHZ 7 > #define TIF_SYSCALL_TRACE 8 /* syscall trace active */ > #define TIF_SYSCALL_AUDIT 9 /* syscall auditing */ > @@ -83,6 +84,7 @@ void arch_release_task_struct(struct task_struct *tsk); > #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) > #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) > #define _TIF_FOREIGN_FPSTATE (1 << TIF_FOREIGN_FPSTATE) > +#define _TIF_TASK_ISOLATION (1 << TIF_TASK_ISOLATION) > #define _TIF_NOHZ (1 << TIF_NOHZ) > #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) > #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) > @@ -96,7 +98,8 @@ void arch_release_task_struct(struct task_struct *tsk); > > #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \ > _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \ > - _TIF_UPROBE | _TIF_FSCHECK) > + _TIF_UPROBE | _TIF_FSCHECK | \ > + _TIF_TASK_ISOLATION) > > #define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ > _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \ > diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c > index cd6e5fa48b9c..b35b9b0c594c 100644 > --- a/arch/arm64/kernel/ptrace.c > +++ b/arch/arm64/kernel/ptrace.c > @@ -29,6 +29,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -1836,6 +1837,15 @@ int syscall_trace_enter(struct pt_regs *regs) > return -1; > } > > + /* > + * In task isolation mode, we may prevent the syscall from > + * running, and if so we also deliver a signal to the process. > + */ > + if (test_thread_flag(TIF_TASK_ISOLATION)) { > + if (task_isolation_syscall(regs->syscallno) == -1) Please use NO_SYSCALL rather than -1 here. > + return -1; > + } > + > /* Do the secure computing after ptrace; failures should be fast. */ > if (secure_computing() == -1) > return -1; > diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c > index 339882db5a91..d488c91a4877 100644 > --- a/arch/arm64/kernel/signal.c > +++ b/arch/arm64/kernel/signal.c > @@ -20,6 +20,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -898,6 +899,11 @@ static void do_signal(struct pt_regs *regs) > restore_saved_sigmask(); > } > > +#define NOTIFY_RESUME_LOOP_FLAGS \ > + (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \ > + _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \ > + _TIF_UPROBE | _TIF_FSCHECK) > + > asmlinkage void do_notify_resume(struct pt_regs *regs, > unsigned long thread_flags) > { > @@ -908,6 +914,8 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, > */ > trace_hardirqs_off(); > > + task_isolation_check_run_cleanup(); > + > do { > /* Check valid user FS if needed */ > addr_limit_user_check(); > @@ -938,7 +946,10 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, > > local_daif_mask(); > thread_flags = READ_ONCE(current_thread_info()->flags); > - } while (thread_flags & _TIF_WORK_MASK); > + } while (thread_flags & NOTIFY_RESUME_LOOP_FLAGS); > + > + if (thread_flags & _TIF_TASK_ISOLATION) > + task_isolation_start(); > } > > unsigned long __ro_after_init signal_minsigstksz; > diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c > index d4ed9a19d8fe..00f0f77adea0 100644 > --- a/arch/arm64/kernel/smp.c > +++ b/arch/arm64/kernel/smp.c > @@ -32,6 +32,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -818,6 +819,7 @@ void arch_send_call_function_single_ipi(int cpu) > #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL > void arch_send_wakeup_ipi_mask(const struct cpumask *mask) > { > + task_isolation_remote_cpumask(mask, "wakeup IPI"); > smp_cross_call(mask, IPI_WAKEUP); > } > #endif > @@ -886,6 +888,9 @@ void handle_IPI(int ipinr, struct pt_regs *regs) > __inc_irq_stat(cpu, ipi_irqs[ipinr]); > } > > + task_isolation_interrupt("IPI type %d (%s)", ipinr, > + ipinr < NR_IPI ? ipi_types[ipinr] : "unknown"); When I previously asked about tracing, I was asking about the format strings, since we don't bother with that kind of thing elsewhere. What exactly are these hooks used for? I assume the strings are only there as a debugging aid? What about other IRQs? Does we need something in the irqchip driver? If we need to track that /any/ interrupt was received, I think that would be better to put in the top-level interrupt exception handler than to sprinkle hooks into every potential handler. > + > switch (ipinr) { > case IPI_RESCHEDULE: > scheduler_ipi(); > @@ -948,12 +953,14 @@ void handle_IPI(int ipinr, struct pt_regs *regs) > > void smp_send_reschedule(int cpu) > { > + task_isolation_remote(cpu, "reschedule IPI"); > smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE); > } > > #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST > void tick_broadcast(const struct cpumask *mask) > { > + task_isolation_remote_cpumask(mask, "timer IPI"); > smp_cross_call(mask, IPI_TIMER); > } > #endif > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index 85566d32958f..fc4b42c81c4f 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -23,6 +23,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -543,6 +544,10 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, > */ > if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | > VM_FAULT_BADACCESS)))) { > + /* No signal was generated, but notify task-isolation tasks. */ > + if (user_mode(regs)) > + task_isolation_interrupt("page fault at %#lx", addr); This isn't an interrupt. Why do we need to hook this? What about /other/ exceptions caused by userspace? If we need to notify userspace, it would be much more reliable to do so in the return path. Thanks, Mark. > + > /* > * Major/minor page fault accounting is only done > * once. If we go through a retry, it is extremely > -- > 2.20.1 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel