Hi,

On 8/31/21 3:05 PM, Hans de Goede wrote:

Commit e26f023e01ef ("firmware/dmi: Include product_sku info to modalias") added a new field to the modalias in the middle of the modalias, breaking some existing udev/hwdb matches on the whole modalias without a wildcard ('*') in between the pvr and rvn fields.

All modalias matches in e.g. : https://github.com/systemd/systemd/blob/main/hwdb.d/60-sensor.hwdb deliberately end in ':*' so that new fields can be added at *the end* of the modalias, but adding a new field in the middle like this breaks things.

Move the new sku field to the end of the modalias to fix some hwdb entries no longer matching.

The new sku field has already been put to use in 2 new hwdb entries:

sensor:modalias:platform:HID-SENSOR-200073:dmi:*svnDell*:sku0A3E:* ACCEL_LOCATION=base

sensor:modalias:platform:HID-SENSOR-200073:dmi:*svnDell*:sku0B0B:* ACCEL_LOCATION=base

The wildcard use before and after the sku in these matches means that they should keep working with the sku moved to the end.

Note that there is a second instance of in essence the same problem, commit f5152f4ded3c ("firmware/dmi: Report DMI Bios & EC firmware release")

Added 2 new br and efr fields in the middle of the modalias. This too breaks some hwdb modalias matches, but this has gone unnoticed for over a year. So some newer hwdb modalias matches actually depend on these fields being in the middle of the string. Moving these to the end now would break 3 hwdb entries, while fixing 8 entries.

Since there is no good answer for the new br and efr fields I have chosen to leave these as is. Instead I'll submit a hwdb update to put a wildcard at the place where these fields may or may not be present depending on the kernel version.

In case anyone is interested here is the systemd pull-req fixing this from the hwdb side: https://github.com/systemd/systemd/pull/20599

Regards,

Hans

BugLink: https://github.com/systemd/systemd/issues/20550 Link: https://github.com/systemd/systemd/pull/20562 Fixes: e26f023e01ef ("firmware/dmi: Include product_sku info to modalias") Cc: stable@vger.kernel.org Cc: Kai-Chuan Hsieh kaichuan.hsieh@canonical.com Cc: Erwan Velu e.velu@criteo.com Signed-off-by: Hans de Goede hdegoede@redhat.com

---

drivers/firmware/dmi-id.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/dmi-id.c b/drivers/firmware/dmi-id.c index 4d5421d14a41..940ddf916202 100644 --- a/drivers/firmware/dmi-id.c +++ b/drivers/firmware/dmi-id.c @@ -73,6 +73,10 @@ static void ascii_filter(char *d, const char *s) static ssize_t get_modalias(char *buffer, size_t buffer_size) {

• /*

• * Note new fields need to be added at the end to keep compatibility
  

• * with udev's hwdb which does matches on "`cat dmi/id/modalias`*".
  

• */
  

  static const struct mafield { const char *prefix; int field;

@@ -85,13 +89,13 @@ static ssize_t get_modalias(char *buffer, size_t buffer_size) { "svn", DMI_SYS_VENDOR }, { "pn", DMI_PRODUCT_NAME }, { "pvr", DMI_PRODUCT_VERSION },

• { "sku", DMI_PRODUCT_SKU },
  

  { "rvn", DMI_BOARD_VENDOR }, { "rn", DMI_BOARD_NAME }, { "rvr", DMI_BOARD_VERSION }, { "cvn", DMI_CHASSIS_VENDOR }, { "ct", DMI_CHASSIS_TYPE }, { "cvr", DMI_CHASSIS_VERSION },

• { "sku", DMI_PRODUCT_SKU },
  

  { NULL, DMI_NONE } };