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 2B3D6264A65 for ; Sat, 17 Jan 2026 22:08:41 +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=1768687721; cv=none; b=ruI/NS6hxpX22ntfBEsmOucqWa/SypWdA53v+JO6gvnCuvT4nF16R1jLWJqbvy78ZW0D+p9m34NdqnGHdHt6b1W+ptXG7JtTF1MgAVfYDWqMrJvNmU76UY9a8Nkd9bShBjbqM6hYNahYg5Iy9xWUm4WN7L266TWaRym8zBa0MUc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768687721; c=relaxed/simple; bh=ZBK4u82lVrks4afuClzeyooZCcEFHeffC+gOZBIFIp0=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=udiusiX+CXAzd80BQAhCHfPFDEqlfOR9HvAxq/fSTENoNGKOfwiw/XFI1oO8C95r4A1wqrQ5rR6bm+NaL6JfdqkxmLnq1iuF4kQ0NjqgxALdoOLE5p41XiLqpgU7SMYrQEOtxmvvBqyJJROLA85VqUjgEauNmzSZsziHg4pRWeU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gFRUGgSS; 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="gFRUGgSS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4630EC4CEF7; Sat, 17 Jan 2026 22:08:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768687720; bh=ZBK4u82lVrks4afuClzeyooZCcEFHeffC+gOZBIFIp0=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=gFRUGgSSMqqF44WbcEXZVxkIKAUZUUjoAnfG0YlU9S2TYUZtVJhx4HdOQIFg3RUVU h1YMFnnXguAwspMAjoexIOkSJ9lVdbC8Wb3ThJtsb5cGBnRGZL+PZJTbyKacmV1ck2 wDLJPNhYSo6E+EVc6DmZ+YFTGwK9J+qI78bIipT+MLX4O/+kd8yzxu0WncZbwaKc7K PBBAORYLPSoJu8Lu8EUPbyZS4XXlHrjF7v0nGli9udSWs7P8WKofG8N2pzoBAZ/xvp VjFwMN6VPh8a59dxl+VoBOBh5fvcV42pUiTvk+GszotJb+5YQFRS9vsGJzOMjeKjkm W9s3ojdmdbLng== From: Thomas Gleixner To: Chris Mason , Vladimir Kondratiev Cc: Chris Mason , Xu Lu , linux-kernel@vger.kernel.org Subject: Re: [PATCH] irqchip/aslint-sswi: request IO memory resource In-Reply-To: <20260116124257.78357-1-clm@meta.com> References: <20260116124257.78357-1-clm@meta.com> Date: Sat, 17 Jan 2026 23:08:37 +0100 Message-ID: <878qdv3na2.ffs@tglx> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Fri, Jan 16 2026 at 04:42, Chris Mason wrote: > On Tue, 9 Dec 2025 16:23:33 +0200 Vladimir Kondratiev wrote: > >> Make an aclint_sswi instance visible in the resource list, >> i.e. /proc/iomem >> > > Hi everyone, > > I ran tip master through my AI review prompts, and this one was flagged. > This is a lot of words for NULL vs ERR_PTR, but it looks right to me: > >> diff --git a/drivers/irqchip/irq-aclint-sswi.c b/drivers/irqchip/irq-aclint-sswi.c >> index fee30f3bc5ac2..325501f34a9bc 100644 >> --- a/drivers/irqchip/irq-aclint-sswi.c >> +++ b/drivers/irqchip/irq-aclint-sswi.c >> @@ -109,7 +109,7 @@ static int __init aclint_sswi_probe(struct fwnode_handle *fwnode) >> if (!is_of_node(fwnode)) >> return -EINVAL; >> >> - reg = of_iomap(to_of_node(fwnode), 0); >> + reg = of_io_request_and_map(to_of_node(fwnode), 0, NULL); >> if (!reg) >> return -ENOMEM; > > Should this error check be updated? of_iomap() returns NULL on failure, > but of_io_request_and_map() returns IOMEM_ERR_PTR() on failure which is > non-NULL. > > When of_io_request_and_map() fails, the condition (!reg) will be false > and the function continues with an invalid ERR_PTR value. This gets passed > to aclint_sswi_parse_irq() which stores (reg + offset) into per_cpu > sswi_cpu_regs, leading to a crash when IPIs are later sent. > > Other callers of of_io_request_and_map() in drivers/irqchip/ use IS_ERR() > for the error check. For example, sun6i_r_intc_init() in irq-sun6i-r.c: > > base = of_io_request_and_map(node, 0, NULL); > if (IS_ERR(base)) { > pr_err("%pOF: Failed to map MMIO region\n", node); > return PTR_ERR(base); > } That's correct. Does anyone care to send a patch? Thanks, tglx