[{"id":3676663,"web_url":"http://patchwork.ozlabs.org/comment/3676663/","msgid":"<8424773e-84cd-25dc-6591-dd68292150fd@linux.intel.com>","list_archive_url":null,"date":"2026-04-13T11:24:23","subject":"Re: [PATCH v4 03/24] PCI/sysfs: Only allow supported resource types\n in I/O and MMIO helpers","submitter":{"id":83553,"url":"http://patchwork.ozlabs.org/api/people/83553/","name":"Ilpo Järvinen","email":"ilpo.jarvinen@linux.intel.com"},"content":"On Sat, 11 Apr 2026, Krzysztof Wilczyński wrote:\n\n> Currently, when the sysfs attributes for PCI resources are added\n> dynamically, the resource access callbacks are only set when the\n> underlying BAR type matches, using .read and .write for IORESOURCE_IO,\n> and .mmap for IORESOURCE_MEM or IORESOURCE_IO with arch_can_pci_mmap_io()\n> support. As such, when the callback is not set, the operation inherently\n> fails.\n> \n> After the conversion to static attributes, visibility callbacks will\n> control which resource files appear for each BAR, but the callbacks\n> themselves will always be set.\n> \n> Thus, add a type check to pci_resource_io() and pci_mmap_resource()\n> to return -EIO for an unsupported resource type.\n> \n> Use the new pci_resource_is_io() and pci_resource_is_mem() helpers\n> for the type checks, replacing the open-coded bitwise flag tests and\n> also drop the local struct resource pointer in pci_mmap_resource().\n> \n> Signed-off-by: Krzysztof Wilczyński \n> ---\n> drivers/pci/pci-sysfs.c | 13 ++++++++++---\n> 1 file changed, 10 insertions(+), 3 deletions(-)\n> \n> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c\n> index ad3c17f86c7f..6783c6168445 100644\n> --- a/drivers/pci/pci-sysfs.c\n> +++ b/drivers/pci/pci-sysfs.c\n> @@ -1108,20 +1108,24 @@ static int pci_mmap_resource(struct kobject *kobj, const struct bin_attribute *a\n> \tstruct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));\n> \tint bar = (unsigned long)attr->private;\n> \tenum pci_mmap_state mmap_type;\n> -\tstruct resource *res = pci_resource_n(pdev, bar);\n> \tint ret;\n> \n> \tret = security_locked_down(LOCKDOWN_PCI_ACCESS);\n> \tif (ret)\n> \t\treturn ret;\n> \n> -\tif (res->flags & IORESOURCE_MEM && iomem_is_exclusive(res->start))\n> +\tif (!pci_resource_is_mem(pdev, bar) &&\n> +\t !(pci_resource_is_io(pdev, bar) && arch_can_pci_mmap_io()))\n> +\t\treturn -EIO;\n> +\n> +\tif (pci_resource_is_mem(pdev, bar) &&\n> +\t iomem_is_exclusive(pci_resource_start(pdev, bar)))\n> \t\treturn -EINVAL;\n> \n> \tif (!pci_mmap_fits(pdev, bar, vma, PCI_MMAP_SYSFS))\n> \t\treturn -EINVAL;\n> \n> -\tmmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;\n> +\tmmap_type = pci_resource_is_mem(pdev, bar) ? pci_mmap_mem : pci_mmap_io;\n> \n> \treturn pci_mmap_resource_range(pdev, bar, vma, mmap_type, write_combine);\n> }\n> @@ -1149,6 +1153,9 @@ static ssize_t pci_resource_io(struct file *filp, struct kobject *kobj,\n> \tint bar = (unsigned long)attr->private;\n> \tunsigned long port = off;\n> \n> +\tif (!pci_resource_is_io(pdev, bar))\n> +\t\treturn -EIO;\n> +\n> \tport += pci_resource_start(pdev, bar);\n> \n> \tif (port > pci_resource_end(pdev, bar))\n> \n\nReviewed-by: Ilpo Järvinen ","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256\n header.s=Intel header.b=cKP5JmRz;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c04:e001:36c::12fc:5321; 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a=\"76177567\"","E=Sophos;i=\"6.23,177,1770624000\";\n d=\"scan'208\";a=\"76177567\"","E=Sophos;i=\"6.23,177,1770624000\";\n d=\"scan'208\";a=\"252952094\""],"X-ExtLoop1":"1","From":"=?utf-8?q?Ilpo_J=C3=A4rvinen?= ","Date":"Mon, 13 Apr 2026 14:24:23 +0300 (EEST)","To":"=?iso-8859-2?q?Krzysztof_Wilczy=F1ski?= ","cc":"Bjorn Helgaas , Bjorn Helgaas ,\n Manivannan Sadhasivam ,\n Lorenzo Pieralisi ,\n Magnus Lindholm , Matt Turner ,\n Richard Henderson ,\n Christophe Leroy ,\n Madhavan Srinivasan ,\n Michael Ellerman , Nicholas Piggin ,\n Dexuan Cui ,\n =?iso-8859-2?q?Krzysztof_Ha=B3asa?= ,\n Lukas Wunner , Oliver O'Halloran ,\n Saurabh Singh Sengar ,\n Shuan He ,\n Srivatsa Bhat , linux-pci@vger.kernel.org,\n linux-alpha@vger.kernel.org, linuxppc-dev@lists.ozlabs.org","Subject":"Re: [PATCH v4 03/24] PCI/sysfs: Only allow supported resource types\n in I/O and MMIO helpers","In-Reply-To":"<20260411080148.471335-4-kwilczynski@kernel.org>","Message-ID":"<8424773e-84cd-25dc-6591-dd68292150fd@linux.intel.com>","References":"<20260411080148.471335-1-kwilczynski@kernel.org>\n <20260411080148.471335-4-kwilczynski@kernel.org>","Precedence":"bulk","X-Mailing-List":"linux-pci@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"multipart/mixed; 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