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 E134532E12E for ; Mon, 11 May 2026 07:14:07 +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=1778483648; cv=none; b=lLcoF7bjSl59S66iowrgxUacSocF/GyyBCU8vfuDdKmStHOpNGaDtoT/A8+l+PhKryVpgXK2+fYPQJQr5l+RTZIiooQxS4dflttdBT+DEBcUkvNh12qVX0Tgxqcu92wwL3bbQ751fOZ5SppUDNt7lNyENRIymAQn2pnwEfdRy9g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778483648; c=relaxed/simple; bh=aD0oB9gmwRWQUB9xicLLUi+hCFnuwHerCdJO1AzMbsM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=pfCRzD6P10zMAvxRdzx4kgoxzoQdpKZQr7ykrkIP8VUsG00fVrq4ty6uy27LBcL0h7js+wMLxPiZvt8oTm+SIAAKQl9OuK2s0QVIW3zN+dZGBKdHzFDuPFsVYbyRqaDAFdI2/JQaE1kOmtoNKoozzyZO/PAssL+74LI6BmiDmME= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hAVKejD+; 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="hAVKejD+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3FED1C2BCB0; Mon, 11 May 2026 07:14:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778483647; bh=aD0oB9gmwRWQUB9xicLLUi+hCFnuwHerCdJO1AzMbsM=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=hAVKejD+41JQsG5IEOsQimQIjVB3NUfApEP0onjdOiPcxKNvlhnumYSx/fEwELizJ QMstq1k3yRaGfNCNWx34RXxNlKGL5Zz2FkdQmupdA3e9Mf/wTcHoM7KHxBR/ORCo9n hxUryIih82MkSchBcxJKRlAvODsB7mbHOBmM9MMc9WP+gnYYzQeFqKVUzYQuM7pO/p VSRXFx72R5Wkqfx9PBd8HM+8U24ouGBqjgpc9YjGvP8iQy/RL9W3MlXgfNt1fFaP0i sDBCjh8I/SkUaLcjGXg/wqauHyJNHLoFHIZtOa/b/NefGYTvAWMRr+/H58XrUywm2p nW8eR8k8C2VcA== Message-ID: <74d3f0c5-b258-4564-9dd4-aec3c6ad297e@kernel.org> Date: Mon, 11 May 2026 09:14:04 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] resource: export iomem_get_mapping() for loadable modules To: Ravi Kumar Bandi , Bjorn Helgaas , =?UTF-8?Q?Ilpo_J=C3=A4rvinen?= , Andrew Morton , Dan Williams Cc: linux-kernel@vger.kernel.org References: <20260511065637.40739-1-ravib@amazon.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/11/26 08:56, Ravi Kumar Bandi wrote: > Loadable PCIe driver modules that handle surprise removal or link-down > events need to zap userspace mappings of PCI BAR resources to deliver > SIGBUS on next access, rather than leaving stale mappings to a dead > device. > > The correct way to do this is via unmap_mapping_range() on the iomem > address space, which is already exported via EXPORT_SYMBOL. > However, iomem_get_mapping() which returns the iomem address space > is not exported, making it impossible to use unmap_mapping_range() > correctly from a loadable module without resorting to workarounds > such as walking all process VMAs or opening /dev/mem. > > Export iomem_get_mapping() via EXPORT_SYMBOL_GPL to complete the > existing exported API and allow loadable modules to properly zap > PCI BAR mappings on device removal. > > Signed-off-by: Ravi Kumar Bandi > --- > kernel/resource.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/resource.c b/kernel/resource.c > index d02a53fb95d8..8801e390fe2e 100644 > --- a/kernel/resource.c > +++ b/kernel/resource.c > @@ -1311,6 +1311,7 @@ struct address_space *iomem_get_mapping(void) > */ > return smp_load_acquire(&iomem_inode)->i_mapping; > } > +EXPORT_SYMBOL_GPL(iomem_get_mapping); > > static int __request_region_locked(struct resource *res, struct resource *parent, > resource_size_t start, resource_size_t n, Which in-tree driver wants to make use of this? -- Cheers, David