Change in osmocom-bb[master]: trxcon/scheduler: be safe against a theoretical integer overflow

[fixeria]

Hello Jenkins Builder, 

I'd like you to reexamine a change. Please visit

    https://gerrit.osmocom.org/c/osmocom-bb/+/17449

to look at the new patch set (#2).

Change subject: trxcon/scheduler: be safe against a theoretical integer overflow
......................................................................

trxcon/scheduler: be safe against a theoretical integer overflow

As was noted by Pau Espin Pedrol, there is a theoretical chance
that lchan->tdma.num_proc would overflow, so as a consequence,
subst_frame_loss() will be unable to compensate one
(potentionally lost) Downlink burst.

On practice, given the size of unsigned long and duration of a
single TDMA frame, it would only happen once in roughly ~6 years.

  FRAME_DURATION = 4615 * 10e-6
  ULONG_MAX = 2 ** 32 - 1

  FRAME_DURATION * ULONG_MAX -> ~198212740 seconds
                             -> ~55059 hours
                             -> ~2294 days
                             -> ~6 years.

Chances are that trxcon would crash much earlier, or even GSM
would be completely forgotten after such a long time run, but
let's work this around and simply start counting from 1
if that overflow eventually happens.

Change-Id: I3d40ef09b06039a85df52af06ab38de314e1a434
---
M src/host/trxcon/sched_trx.c
1 file changed, 10 insertions(+), 1 deletion(-)


  git pull ssh://gerrit.osmocom.org:29418/osmocom-bb refs/changes/49/17449/2
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Gerrit-Project: osmocom-bb
Gerrit-Branch: master
Gerrit-Change-Id: I3d40ef09b06039a85df52af06ab38de314e1a434
Gerrit-Change-Number: 17449
Gerrit-PatchSet: 2
Gerrit-Owner: fixeria <axilirator at gmail.com>
Gerrit-Reviewer: Jenkins Builder
Gerrit-MessageType: newpatchset
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