On Tue, Dec 03, 2024 at 09:24:56AM -0800, Stephen Hemminger wrote: > On Tue, 3 Dec 2024 14:15:28 +0200 > Leon Romanovsky <leon@xxxxxxxxxx> wrote: > > > The Vital Product Data (VPD) attribute is not readable by regular > > user without root permissions. Such restriction is not needed at > > all for Mellanox devices, as data presented in that VPD is not > > sensitive and access to the HW is safe and well tested. > > > > This change changes the permissions of the VPD attribute to be accessible > > for read by all users for Mellanox devices, while write continue to be > > restricted to root only. > > > > The main use case is to remove need to have root/setuid permissions > > while using monitoring library [1]. > > > > [leonro@vm ~]$ lspci |grep nox > > 00:09.0 Ethernet controller: Mellanox Technologies MT2910 Family [ConnectX-7] > > > > Before: > > [leonro@vm ~]$ ls -al /sys/bus/pci/devices/0000:00:09.0/vpd > > -rw------- 1 root root 0 Nov 13 12:30 /sys/bus/pci/devices/0000:00:09.0/vpd > > After: > > [leonro@vm ~]$ ls -al /sys/bus/pci/devices/0000:00:09.0/vpd > > -rw-r--r-- 1 root root 0 Nov 13 12:30 /sys/bus/pci/devices/0000:00:09.0/vpd > > > > [1] https://developer.nvidia.com/management-library-nvml > > Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx> > > --- > > Changelog: > > v3: > > * Used | to change file attributes > > * Remove WARN_ON > > v2: https://lore.kernel.org/all/61a0fa74461c15edfae76222522fa445c28bec34.1731502431.git.leon@xxxxxxxxxx > > * Another implementation to make sure that user is presented with > > correct permissions without need for driver intervention. > > v1: https://lore.kernel.org/all/cover.1731005223.git.leonro@xxxxxxxxxx > > * Changed implementation from open-read-to-everyone to be opt-in > > * Removed stable and Fixes tags, as it seems like feature now. > > v0: > > https://lore.kernel.org/all/65791906154e3e5ea12ea49127cf7c707325ca56.1730102428.git.leonro@xxxxxxxxxx/ > > --- > > drivers/pci/vpd.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/drivers/pci/vpd.c b/drivers/pci/vpd.c > > index a469bcbc0da7..a7aa54203321 100644 > > --- a/drivers/pci/vpd.c > > +++ b/drivers/pci/vpd.c > > @@ -332,6 +332,13 @@ static umode_t vpd_attr_is_visible(struct kobject *kobj, > > if (!pdev->vpd.cap) > > return 0; > > > > + /* > > + * Mellanox devices have implementation that allows VPD read by > > + * unprivileged users, so just add needed bits to allow read. > > + */ > > + if (unlikely(pdev->vendor == PCI_VENDOR_ID_MELLANOX)) > > + return a->attr.mode | 0044; > > + > > return a->attr.mode; > > } > > > > Could this be with other vendor specific quirks instead? In previous versions, I asked Bjorn about using quirks and the answer was that quirks are mainly to fix HW defects fixes and this change doesn't belong to that category. https://lore.kernel.org/linux-pci/20241111214804.GA1820183@bhelgaas/ > > Also, the wording of the comment is awkward. Suggest: > On Mellanox devices reading VPD is safe for unprivileged users. Thanks
