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From: Greg KH <greg@kroah.com>
To: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	yj.chiang@mediatek.com,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	stable@vger.kernel.org, Masami Hiramatsu <mhiramat@kernel.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org
Subject: Re: [PATCH 5.4] arm64: kprobes: Use BRK instead of single-step when executing instructions out-of-line
Date: Mon, 20 Jun 2022 13:53:41 +0200	[thread overview]
Message-ID: <YrBfxXwumb30FEtV@kroah.com> (raw)
In-Reply-To: <20220615015928.19181-1-mark-pk.tsai@mediatek.com>

On Wed, Jun 15, 2022 at 09:59:23AM +0800, Mark-PK Tsai wrote:
> From: Jean-Philippe Brucker <jean-philippe@linaro.org>
> 
> commit 7ee31a3aa8f490c6507bc4294df6b70bed1c593e upstream.
> 
> Commit 36dadef23fcc ("kprobes: Init kprobes in early_initcall") enabled
> using kprobes from early_initcall. Unfortunately at this point the
> hardware debug infrastructure is not operational. The OS lock may still
> be locked, and the hardware watchpoints may have unknown values when
> kprobe enables debug monitors to single-step instructions.
> 
> Rather than using hardware single-step, append a BRK instruction after
> the instruction to be executed out-of-line.
> 
> Fixes: 36dadef23fcc ("kprobes: Init kprobes in early_initcall")
> Suggested-by: Will Deacon <will@kernel.org>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
> Link: https://lore.kernel.org/r/20201103134900.337243-1-jean-philippe@linaro.org
> Signed-off-by: Will Deacon <will@kernel.org>
> Link: https://lore.kernel.org/lkml/20220610063619.7921-1-mark-pk.tsai@mediatek.com/
> Cc: stable@vger.kernel.org
> Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>

Now queued up, thanks.

greg k-h

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      reply	other threads:[~2022-06-20 11:55 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-15  1:59 [PATCH 5.4] arm64: kprobes: Use BRK instead of single-step when executing instructions out-of-line Mark-PK Tsai
2022-06-20 11:53 ` Greg KH [this message]

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