From: mark.rutland@arm.com (Mark Rutland)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/4] arm64: kprobes: WARN if attempting to step with PSTATE.D=1
Date: Tue, 19 Jul 2016 15:37:16 +0100 [thread overview]
Message-ID: <20160719143716.GB22473@leverpostej> (raw)
In-Reply-To: <1468937260-23988-3-git-send-email-will.deacon@arm.com>
On Tue, Jul 19, 2016 at 03:07:39PM +0100, Will Deacon wrote:
> Stepping with PSTATE.D=1 is bad news. The step won't generate a debug
> exception and we'll likely walk off into random data structures. This
> should never happen, but when it does, it's a PITA to debug. Add a
> WARN_ON to shout if we realise this is about to take place.
>
> Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Mark.
> ---
> arch/arm64/kernel/probes/kprobes.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
> index 9c70e8812ea9..c89811d1e294 100644
> --- a/arch/arm64/kernel/probes/kprobes.c
> +++ b/arch/arm64/kernel/probes/kprobes.c
> @@ -254,6 +254,8 @@ static void __kprobes setup_singlestep(struct kprobe *p,
>
> if (kcb->kprobe_status == KPROBE_REENTER)
> spsr_set_debug_flag(regs, 0);
> + else
> + WARN_ON(regs->pstate & PSR_D_BIT);
>
> /* IRQs and single stepping do not mix well. */
> kprobes_save_local_irqflag(kcb, regs);
> --
> 2.1.4
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
next prev parent reply other threads:[~2016-07-19 14:37 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-19 14:07 [PATCH 1/4] arm64: debug: unmask PSTATE.D earlier Will Deacon
2016-07-19 14:07 ` [PATCH 2/4] arm64: debug: remove redundant spsr manipulation Will Deacon
2016-07-19 14:36 ` Mark Rutland
2016-07-19 14:07 ` [PATCH 3/4] arm64: kprobes: WARN if attempting to step with PSTATE.D=1 Will Deacon
2016-07-19 14:37 ` Mark Rutland [this message]
2016-08-03 12:22 ` Pratyush Anand
2016-08-09 12:48 ` Will Deacon
2016-08-10 8:01 ` Pratyush Anand
2016-08-10 12:04 ` Masami Hiramatsu
2016-08-12 12:46 ` Pratyush Anand
2016-08-15 12:56 ` Pratyush Anand
2016-07-19 14:07 ` [PATCH 4/4] arm64: debug: remove unused local_dbg_{enable, disable} macros Will Deacon
2016-07-19 14:38 ` Mark Rutland
2016-07-19 14:23 ` [PATCH 1/4] arm64: debug: unmask PSTATE.D earlier Catalin Marinas
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