From: Will Deacon <will@kernel.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: elver@google.com, paulmck@kernel.org, peterz@infradead.org,
catalin.marinas@arm.com, james.morse@arm.com,
linux-arm-kernel@lists.infradead.org, dvyukov@google.com
Subject: Re: [PATCH 07/11] arm64: entry: fix non-NMI user<->kernel transitions
Date: Mon, 30 Nov 2020 11:22:35 +0000 [thread overview]
Message-ID: <20201130112234.GE24098@willie-the-truck> (raw)
In-Reply-To: <20201126123602.23454-8-mark.rutland@arm.com>
On Thu, Nov 26, 2020 at 12:35:58PM +0000, Mark Rutland wrote:
> When built with PROVE_LOCKING, NO_HZ_FULL, and CONTEXT_TRACKING_FORCE
> will WARN() at boot time that interrupts are enabled when we call
> context_tracking_user_enter(), despite the DAIF flags indicating that
> IRQs are masked.
>
> The problem is that we're not tracking IRQ flag changes accurately, and
> so lockdep believes interrupts are enabled when they are not (and
> vice-versa). We can shuffle things so to make this more accurate. For
> kernel->user transitions there are a number of constraints we need to
> consider:
[...]
> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index 53e30750fc28..d17a68c24608 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
> @@ -30,18 +30,18 @@
> #include <asm/unistd.h>
>
> /*
> - * Context tracking subsystem. Used to instrument transitions
> - * between user and kernel mode.
> + * Context tracking and irqflag tracing need to inrstrument transitions between
Typo: "inrstrument".
Will
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next prev parent reply other threads:[~2020-11-30 11:23 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-26 12:35 [PATCH 00/11] arm64: entry lockdep/rcu/tracing fixes Mark Rutland
2020-11-26 12:35 ` [PATCH 01/11] arm64: syscall: exit userspace before unmasking exceptions Mark Rutland
2020-11-26 12:35 ` [PATCH 02/11] arm64: mark idle code as noinstr Mark Rutland
2020-11-26 12:35 ` [PATCH 03/11] arm64: entry: mark entry " Mark Rutland
2020-11-26 12:35 ` [PATCH 04/11] arm64: entry: move enter_from_user_mode to entry-common.c Mark Rutland
2020-11-26 12:35 ` [PATCH 05/11] arm64: entry: prepare ret_to_user for function call Mark Rutland
2020-11-26 12:35 ` [PATCH 06/11] arm64: entry: move el1 irq/nmi logic to C Mark Rutland
2020-11-26 12:35 ` [PATCH 07/11] arm64: entry: fix non-NMI user<->kernel transitions Mark Rutland
2020-11-30 11:22 ` Will Deacon [this message]
2020-11-26 12:35 ` [PATCH 08/11] arm64: ptrace: prepare for EL1 irq/rcu tracking Mark Rutland
2020-11-30 11:01 ` Will Deacon
2020-11-26 12:36 ` [PATCH 09/11] arm64: entry: fix non-NMI kernel<->kernel transitions Mark Rutland
2020-11-30 11:22 ` Will Deacon
2020-11-26 12:36 ` [PATCH 10/11] arm64: entry: fix NMI {user, kernel}->kernel transitions Mark Rutland
2020-11-26 18:41 ` [PATCH 10/11] arm64: entry: fix NMI {user,kernel}->kernel transitions Mark Rutland
2020-11-26 21:00 ` Will Deacon
2020-11-26 12:36 ` [PATCH 11/11] arm64: entry: fix EL1 debug transitions Mark Rutland
2020-11-30 11:23 ` [PATCH 00/11] arm64: entry lockdep/rcu/tracing fixes Will Deacon
2020-11-30 12:03 ` Marco Elver
2020-11-30 12:38 ` Mark Rutland
[not found] ` <20201130133245.GA1307615@elver.google.com>
2020-11-30 16:54 ` Mark Rutland
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