On Sat, 11 Apr 2026, Krzysztof Wilczyński wrote: > Currently, when the sysfs attributes for PCI resources are added > dynamically, the resource access callbacks are only set when the > underlying BAR type matches, using .read and .write for IORESOURCE_IO, > and .mmap for IORESOURCE_MEM or IORESOURCE_IO with arch_can_pci_mmap_io() > support. As such, when the callback is not set, the operation inherently > fails. > > After the conversion to static attributes, visibility callbacks will > control which resource files appear for each BAR, but the callbacks > themselves will always be set. > > Thus, add a type check to pci_resource_io() and pci_mmap_resource() > to return -EIO for an unsupported resource type. > > Use the new pci_resource_is_io() and pci_resource_is_mem() helpers > for the type checks, replacing the open-coded bitwise flag tests and > also drop the local struct resource pointer in pci_mmap_resource(). > > Signed-off-by: Krzysztof Wilczyński <[email protected]> > --- > drivers/pci/pci-sysfs.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c > index ad3c17f86c7f..6783c6168445 100644 > --- a/drivers/pci/pci-sysfs.c > +++ b/drivers/pci/pci-sysfs.c > @@ -1108,20 +1108,24 @@ static int pci_mmap_resource(struct kobject *kobj, > const struct bin_attribute *a > struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj)); > int bar = (unsigned long)attr->private; > enum pci_mmap_state mmap_type; > - struct resource *res = pci_resource_n(pdev, bar); > int ret; > > ret = security_locked_down(LOCKDOWN_PCI_ACCESS); > if (ret) > return ret; > > - if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(res->start)) > + if (!pci_resource_is_mem(pdev, bar) && > + !(pci_resource_is_io(pdev, bar) && arch_can_pci_mmap_io())) > + return -EIO; > + > + if (pci_resource_is_mem(pdev, bar) && > + iomem_is_exclusive(pci_resource_start(pdev, bar))) > return -EINVAL; > > if (!pci_mmap_fits(pdev, bar, vma, PCI_MMAP_SYSFS)) > return -EINVAL; > > - mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io; > + mmap_type = pci_resource_is_mem(pdev, bar) ? pci_mmap_mem : pci_mmap_io; > > return pci_mmap_resource_range(pdev, bar, vma, mmap_type, > write_combine); > } > @@ -1149,6 +1153,9 @@ static ssize_t pci_resource_io(struct file *filp, > struct kobject *kobj, > int bar = (unsigned long)attr->private; > unsigned long port = off; > > + if (!pci_resource_is_io(pdev, bar)) > + return -EIO; > + > port += pci_resource_start(pdev, bar); > > if (port > pci_resource_end(pdev, bar)) >
Reviewed-by: Ilpo Järvinen <[email protected]> -- i.
