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Date: Mon, 19 Aug 2024 19:45:17 +0200
From: Greg KH <gregkh@linuxfoundation.org>
To: Wen Yang <wen.yang@linux.dev>
Cc: Kees Cook <kees@kernel.org>, Tony Luck <tony.luck@intel.com>,
	"Guilherme G. Piccoli" <gpiccoli@igalia.com>,
	linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] pstore: replace spinlock_t by raw_spinlock_t
Message-ID: <2024081925-opposite-pessimist-9b98@gregkh>
References: <20240819145945.61274-1-wen.yang@linux.dev>
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In-Reply-To: <20240819145945.61274-1-wen.yang@linux.dev>

On Mon, Aug 19, 2024 at 10:59:45PM +0800, Wen Yang wrote:
> pstore_dump() is called when both preemption and local IRQ are disabled,
> and a spinlock is obtained, which is problematic for the RT kernel because
> in this configuration, spinlocks are sleep locks.
> 
> Replace the spinlock_t with raw_spinlock_t to avoid sleeping in atomic context.

This feels odd, is it only an out-of-tree RT thing?  Or does this affect
in-kernel code as well?  What prevents any normal spinlock from sleeping
in your system configuration as well?

thanks,

greg k-h