From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 984FA1CD20 for ; Sat, 13 Apr 2024 08:44:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712997852; cv=none; b=cBT/bc75luGRybLkuHj7AE7d2VRDskMOjBrRCREKvo+zBomWudgxAYzgdayBpHNh3CjsNvq6+bndzM8Gn8BmIcBEWC32bLMVLVkZ2S+nok8JQGqw/aqB0stYBxh/O9wy2aOELx+c71Vlr1XfJ5BLnJwK1GcaWKTEyv75uXrtw0o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712997852; c=relaxed/simple; bh=kHjM1Xq6wd71WRSOSKPfkgfBOcQIYnJWZvz8Rf68cbo=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=uxDFM6FOvI0yRoF+xB3J/FXWMGgt6st37W/CvxKv/COG/+dg/1S82c5wa8RweXAHTFi1Rm380qPKi8fVl1i1vP3U8er0qvdG0/LQtFClMzRbnJodLCMDFx1Z4C5vSKwfNfonp4QJRoDhza6TJYnvhHaBaU50OEukwxCHUvl4TtY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sMpq8mPy; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="sMpq8mPy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1CEDCC113CD; Sat, 13 Apr 2024 08:44:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1712997852; bh=kHjM1Xq6wd71WRSOSKPfkgfBOcQIYnJWZvz8Rf68cbo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=sMpq8mPyQ01Uh0Y31wuSNEPAVYYnn6mZh2Le6JPIoQeAv8/jwUwYqKxVkVK2M7LNO IK1jBOU46dnAk+o7N0fM2+eISJEUHnr+/XUlGLxIdC8TA02ycLX1tIIuHPmw6NZY0x Xz/i0MR1oza01o62jtBPrd0iunFFauLl64G/N4ZoOecGoAZgZv3ZXOMHoy8ulK+uNc /LebkAG678ADDx9mI4BmM3EHN+WV1Xt5ZF6oR6mwM/g5O29lODo0dzP01AZFZt2At1 ZpfsZ0UJOp03/fTGBvVE1utiwk87TqVsVJt9THupjwTzIhyX9DhyDXGcxK7rr+hrii 3vZcfd2TFLy5w== Received: from sofa.misterjones.org ([185.219.108.64] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1rvYza-0046hD-0T; Sat, 13 Apr 2024 09:44:10 +0100 Date: Sat, 13 Apr 2024 09:44:13 +0100 Message-ID: <878r1hslcy.wl-maz@kernel.org> From: Marc Zyngier To: Guanrui Huang Cc: yuzenghui@huawei.com, shannon.zhao@linux.alibaba.com, tglx@linutronix.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 2/2] irqchip/gic-v3-its: remove BUG_ON in its_vpe_irq_domain_alloc In-Reply-To: <20240413064051.31315-2-guanrui.huang@linux.alibaba.com> References: <20240413064051.31315-1-guanrui.huang@linux.alibaba.com> <20240413064051.31315-2-guanrui.huang@linux.alibaba.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/28.2 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: guanrui.huang@linux.alibaba.com, yuzenghui@huawei.com, shannon.zhao@linux.alibaba.com, tglx@linutronix.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Sat, 13 Apr 2024 07:40:51 +0100, Guanrui Huang wrote: > > If vm is NULL in here, that means caller has a bug. > BUG_ON in here is useless, this will paper over bug. This BUG_ON() doesn't paper over a bug like your previous patch did. It catches a bug (vm should never be NULL), but also forces the system to crash for no good reason. The same effect will be obtained by letting the code run its course and vm being dereferenced, triggering an exception. > > So just remove this check. > > Signed-off-by: Guanrui Huang > --- > drivers/irqchip/irq-gic-v3-its.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c > index 2305f6b524a9..55c83e19719d 100644 > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -4521,8 +4521,6 @@ static int its_vpe_irq_domain_alloc(struct irq_domain *domain, unsigned int virq > struct page *vprop_page; > int base, nr_ids, i, err = 0; > > - BUG_ON(!vm); > - > bitmap = its_lpi_alloc(roundup_pow_of_two(nr_irqs), &base, &nr_ids); > if (!bitmap) > return -ENOMEM; With the commit message fixed: Acked-by: Marc Zyngier M. -- Without deviation from the norm, progress is not possible.