This was experienced by Daniel on his 64bit machine. The paging
expiration time was too high and not set by the code at all. Using
gdb watchpoints he found the place where the memory is written. The
issue is that the size of the pointer (8) and not the size of the
data structure was copied (3).
Fix the issue by assigning the de-referenced value. gcc generates
the same code as if we had written:
memcpy(&ps->chan_desc, chan_desc, sizeof(*chan_desc));
This may be adding bells and whistles that nobody wants to touch, but at
least for current analysis/optimiziation they are useful to have. Later
on they should probably be removed again and/or obsoleted by OML
messages for configuration of paging behaviour by the BSC.
If someone wants to have paging for a wrong frame, gracefully return
and do not fill the output buffer. Because we are on the wrong frame
I think it is best to not fill the frame, this is why I did not add a
check to l1_if.c to generate an empty frame.
This code re-works osmo-bts to add support for the upcoming sysmocom BTS.
It also tries to add some level of abstraction between the generic
part of a BTS (A-bis, RSL, OML, data structures, paging scheduling,
BCCH/AGCH scheduling, etc.) and the actual hardware-specific bits.
The hardware-specific bits are currently only implemented for the sysmocom
femtobts, but should be (re-)added for osmocom-bb, as well as a virtual
BTS for simulation purpose later.
The sysmocom bts specific parts require hardware-specific header files
which are (at least currently) not publicly distributed.
Holger Hans Peter Freyther
Harald Welte