Re: [PATCH 3/3] platform/x86: Intel PMT Crashlog capability driver
From: Alexey Budankov
Date: Sat Sep 19 2020 - 03:58:46 EST
Thanks for the patches.
On 11.09.2020 22:45, David E. Box wrote:
> From: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
> Add support for the Intel Platform Monitoring Technology crashlog
> interface. This interface provides a few sysfs values to allow for
> controlling the crashlog telemetry interface as well as a character driver
> to allow for mapping the crashlog memory region so that it can be accessed
> after a crashlog has been recorded.
> This driver is meant to only support the server version of the crashlog
> which is identified as crash_type 1 with a version of zero. Currently no
> other types are supported.
> Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
> Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx>
> .../ABI/testing/sysfs-class-pmt_crashlog | 66 ++
> drivers/platform/x86/Kconfig | 10 +
> drivers/platform/x86/Makefile | 1 +
> drivers/platform/x86/intel_pmt_crashlog.c | 588 ++++++++++++++++++
> 4 files changed, 665 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-class-pmt_crashlog
> create mode 100644 drivers/platform/x86/intel_pmt_crashlog.c
> + * devfs
> + */
> +static int pmt_crashlog_open(struct inode *inode, struct file *filp)
> + struct crashlog_entry *entry;
> + struct pci_driver *pci_drv;
> + struct pmt_crashlog_priv *priv;
> + if (!capable(CAP_SYS_ADMIN))
> + return -EPERM;
Will not this above still block access to /dev/crashlogX for admin_group users
in case root configured access e.g. similar to this:
ls -alh /dev/
crw-rw----. 1 root admin_group 1, 9 Sep 15 18:28 crashlogX
If yes then that capable() check is probably superfluous and
should be avoided in order not to block access to PMT data.
Could you please clarify or comment?