2013-06-26 16:20:39

by Lucas De Marchi

[permalink] [raw]
Subject: module refcnt underflow

Hi,

While checking somethings for a next release of kmod I noticed this
strange thing:

cat /sys/module/acpi_cpufreq/refcnt
18446744073709551614

We outputs this as "-1" in lsmod because we treat the value as signed.
I was just going to change it to unsigned to make it compatible with
what module-init-tools does but... For me it looks like a bug in the
kernel since in this file we just have the output of
kernel/module.c:module_refcount()

I have this behavior on 3.9.2 but judging by the missing commits in
kernel/module.c, this would also happen in latest head. I've never
seen such a value so I guess it might be difficult to reproduce it
again.

Any hints on what could cause decs to be greater than incs in module_refcount()?


--

Lucas De Marchi