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From: Joey Gouly <joey.gouly@arm.com>
To: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com,
	james.morse@arm.com, maz@kernel.org, will@kernel.org, nd@arm.com
Subject: Re: [PATCH v2 12/19] arm64: entry: improve bad_mode()
Date: Fri, 21 May 2021 18:02:21 +0100	[thread overview]
Message-ID: <20210521170221.GI35816@e124191.cambridge.arm.com> (raw)
In-Reply-To: <20210519123902.2452-13-mark.rutland@arm.com>

On Wed, May 19, 2021 at 01:38:55PM +0100, Mark Rutland wrote:
> Our use of bad_mode() has a few rough edges:
> 
> * AArch64 doesn't use the term "mode", and refers to "Execution
>   states", "Exception levels", and "Selected stack pointer".
> 
> * We log the exception type (SYNC/IRQ/FIQ/SError), but not the actual
>   "mode" (though this can be deocded from the SPSR value).
> 
> * We use bad_mode() as a second-level handler for unexpected synchronous
>   exceptions, where the "mode" is legitimate, but the specific exception
>   is not.
> 
> * We dump the ESR value, but call this "code", and so it's not clear to
>   all readers that this is the ESR.
> 
> ... and all of this can be someqhat opaque to those who aren't extremely
> familiar with the code.
typo: someqhat -> somewhat

> 
> Let's make this a bit clearer by having bad_mode() log "Unhandled
> ${TYPE} exception" rather than "Bad mode in ${TYPE} handler", using
> "ESR" rather than "code", and having the final panic() log "Unhandled
> exception" rather than "Bad mode".
> 
> In future we'd like to log the specific architectural vector rather than
> just the type of exception, so we also split the core of basd_mode() out
typo: basd_mode -> bad_mode

> into a helper called __panic_unhandled(), which takes the vector as a
> string argument.
> 

Reviewed-by: Joey Gouly <joey.gouly@arm.com>

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  reply	other threads:[~2021-05-21 17:04 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-19 12:38 [PATCH v2 00/19] arm64: entry: migrate more code to C Mark Rutland
2021-05-19 12:38 ` [PATCH v2 01/19] arm64: remove redundant local_daif_mask() in bad_mode() Mark Rutland
2021-05-21 10:39   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 02/19] arm64: entry: unmask IRQ+FIQ after EL0 handling Mark Rutland
2021-05-25 16:45   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 03/19] arm64: entry: convert SError handlers to C Mark Rutland
2021-05-25 13:38   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 04/19] arm64: entry: move arm64_preempt_schedule_irq to entry-common.c Mark Rutland
2021-05-21 11:00   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 05/19] arm64: entry: move preempt logic to C Mark Rutland
2021-05-25 12:50   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 06/19] arm64: entry: add a call_on_irq_stack helper Mark Rutland
2021-05-19 14:46   ` Mark Rutland
2021-05-19 12:38 ` [PATCH v2 07/19] arm64: entry: convert IRQ+FIQ handlers to C Mark Rutland
2021-05-21 13:19   ` Joey Gouly
2021-05-21 15:23     ` Mark Rutland
2021-05-19 12:38 ` [PATCH v2 08/19] arm64: entry: organise entry handlers consistently Mark Rutland
2021-05-21 16:04   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 09/19] arm64: entry: organise entry vectors consistently Mark Rutland
2021-05-21 16:07   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 10/19] arm64: entry: consolidate EL1 exception returns Mark Rutland
2021-05-21 16:22   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 11/19] arm64: entry: move bad_mode() to entry-common.c Mark Rutland
2021-05-21 16:46   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 12/19] arm64: entry: improve bad_mode() Mark Rutland
2021-05-21 17:02   ` Joey Gouly [this message]
2021-05-21 17:10     ` Mark Rutland
2021-05-19 12:38 ` [PATCH v2 13/19] arm64: entry: template the entry asm functions Mark Rutland
2021-05-21 17:16   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 14/19] arm64: entry: handle all vectors with C Mark Rutland
2021-05-21 15:59   ` Joey Gouly
2021-05-21 16:41     ` Mark Rutland
2021-05-19 12:38 ` [PATCH v2 15/19] arm64: entry: split bad stack entry Mark Rutland
2021-05-25 11:25   ` Joey Gouly
2021-05-19 12:38 ` [PATCH v2 16/19] arm64: entry: split SDEI entry Mark Rutland
2021-05-25 11:49   ` Joey Gouly
2021-05-19 12:39 ` [PATCH v2 17/19] arm64: entry: make NMI entry/exit functions static Mark Rutland
2021-05-21 17:21   ` Joey Gouly
2021-05-19 12:39 ` [PATCH v2 18/19] arm64: entry: don't instrument entry code with KCOV Mark Rutland
2021-05-19 12:39 ` [PATCH v2 19/19] arm64: idle: don't instrument idle " Mark Rutland

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