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From: Jiri Slaby <jirislaby@kernel.org>
To: Nathan Chancellor <nathan@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>,
	linux-kernel@vger.kernel.org, llvm@lists.linux.dev
Subject: Re: [PATCH] genirq: Ensure flags in lock guard is consistently initialized
Date: Tue, 13 May 2025 07:22:32 +0200	[thread overview]
Message-ID: <61d1b49c-e2ef-4a43-942d-6e321d4be8c8@kernel.org> (raw)
In-Reply-To: <20250513-irq-guards-fix-flags-init-v1-1-1dca3f5992d6@kernel.org>

On 13. 05. 25, 0:16, Nathan Chancellor wrote:
> After the conversion to locking guards within the interrupt core code,
> several builds with clang show the "Interrupts were enabled early"
> WARN() in start_kernel() on boot.
> 
> In class_irqdesc_lock_constructor(), _t.flags is initialized via
> __irq_get_desc_lock() within the _t initializer list. However, the C11
> standard 6.7.9.23 states that the evaluation of the initialization list
> expressions are indeterminately sequenced relative to one another,
> meaning _t.flags could be initialized by __irq_get_desc_lock() then be
> initialized to zero due to flags being absent from the initializer list.
> 
> To ensure _t.flags is consistently initialized, move the call to
> __irq_get_desc_lock() and the assignment of its result to _t.lock out of
> the designated initializer.
> 
> Fixes: 0f70a49f3fa3 ("genirq: Provide conditional lock guards")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>

thanks,
-- 
js
suse labs

      reply	other threads:[~2025-05-13  5:22 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-05-12 22:16 [PATCH] genirq: Ensure flags in lock guard is consistently initialized Nathan Chancellor
2025-05-13  5:22 ` Jiri Slaby [this message]

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