mcelog fails to initialize when 'dmi' option is turned on

[vpedabal]

After enabling the dmi option in the mcelog.conf file and restarting the mcelog service fails. The 'service mcelog status' shows the following:
linux-y3iu:/home/vpedabal # service mcelog status
mcelog.service - Machine Check Exception Logging Daemon
Loaded: loaded (/usr/lib/systemd/system/mcelog.service; enabled)
Active: failed (Result: exit-code) since Tue 2015-03-17 00:34:01 PDT; 1s ago
Process: 2761 ExecStart=/usr/sbin/mcelog --ignorenodev --daemon --foreground (code=exited, status=1/FAILURE)
Main PID: 2761 (code=exited, status=1/FAILURE)

Is there a way to see what was the underlying failure? The syslog doesn't seem to report anything.

[andikleen]

You can just run the command line outside systemd. It should log all errors to stdout or system log.

One reason for --dmi failing is if the daemon runs as non root or /dev/mem is not accessible or protected.

[vpedabal]

I tried doing that, but it still doesn't output any error, and I am also running it as root. It still works when I don't turn on the --dmi option though.

[ykondrashyn]

It happens when mcelog fails to access /sys/firmware/efi/systab and /proc/efi/systab on your system. I assume they only appear when you have UEFI instead of BIOS. Look at dmi.c for more info.

However, you can run mcelog with --dmi option on non-efi system after slight change in dmi.c:
In this commit there were two strings added (system and return -1), remove them and mcelog will complain about failure to read the dmi tables but it should still work.
3d78289
Another way: try to rebuilt kernel with CONFIG_EFI and CONFIG_MEMORY_FAILURE enabled