Thanks for your contribution. There are several issues with your patch.

1* We have a utility function for reading from /dev/mem in util.c (mem_chunk). You should use that instead of open-coding the same.

2* Your code is executed unconditionally while there are several conditions which must be met for it to work. Specifically, it only works if the log access method is through a Memory-mapped physical 32-bit address (Access Method = 0x03). Also, it can only work if decoding the DMI table of the local machine, so it should be skipped when reading from a dump file. Lastly, we may have to check the "Log area valid" bit before decoding the error log, although the spec says this bit may not always be up-to-date, so I'm not really sure what do to about it.

3* Your code relies on being able to read an arbitrary portion of /dev/mem from userspace. The Linux ecosystem is currently moving away from this approach. The DMI table itself is now read from sysfs, not /dev/mem, whenever possible. Many systems have /dev/mem access restrictions in place nowadays, some don't even have /dev/mem any more.

4* Supporting the other access methods would require poking at I/O ports from userspace. I am not sure if this can be done reliably.