<p>pespin has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/osmo-bts/+/25965">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">l1sap: Avoid re-(de)activating already (de)active lchans<br><br>This avoids triggering all sorts of unexpected paths where one tries to<br>release an already released lchan, etc.<br>This can happen for instance if BTS shuts down due to BSC link going<br>down, and hence resets all lchans, announcing it to the PCU. Then the<br>PCU may try to deactivate the channel sending act_req (disable), but the<br>BTS already unilaterally dropped the channels.<br>That code path seems to trigger some crash, probably because something<br>in lchan has been freed.<br><br>Related: SYS#4971<br>Change-Id: I093e4d4e23b527b10bf5d6ff538460626c30a8f8<br>---<br>M src/common/l1sap.c<br>1 file changed, 13 insertions(+), 0 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/65/25965/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/src/common/l1sap.c b/src/common/l1sap.c</span><br><span>index c89b2c3..2338996 100644</span><br><span>--- a/src/common/l1sap.c</span><br><span>+++ b/src/common/l1sap.c</span><br><span>@@ -1961,6 +1961,12 @@</span><br><span>        struct gsm_lchan *lchan = get_lchan_by_chan_nr(trx, chan_nr);</span><br><span>        int rc;</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+   if (lchan->state == LCHAN_S_ACTIVE) {</span><br><span style="color: hsl(120, 100%, 40%);">+              LOGPLCHAN(lchan, DL1C, LOGL_ERROR, "Trying to activate already active channel %s\n",</span><br><span style="color: hsl(120, 100%, 40%);">+                          rsl_chan_nr_str(chan_nr));</span><br><span style="color: hsl(120, 100%, 40%);">+          return -1;</span><br><span style="color: hsl(120, 100%, 40%);">+    }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span>  LOGPLCHAN(lchan, DL1C, LOGL_INFO, "Activating channel %s\n", rsl_chan_nr_str(chan_nr));</span><br><span> </span><br><span>        lchan->s = trx->bts->radio_link_timeout.current;</span><br><span>@@ -1994,6 +2000,13 @@</span><br><span> int l1sap_chan_rel(struct gsm_bts_trx *trx, uint8_t chan_nr)</span><br><span> {</span><br><span>      struct gsm_lchan *lchan = get_lchan_by_chan_nr(trx, chan_nr);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+       if (lchan->state == LCHAN_S_NONE) {</span><br><span style="color: hsl(120, 100%, 40%);">+                LOGPLCHAN(lchan, DL1C, LOGL_ERROR, "Trying to deactive already deactivated channel %s\n",</span><br><span style="color: hsl(120, 100%, 40%);">+                     rsl_chan_nr_str(chan_nr));</span><br><span style="color: hsl(120, 100%, 40%);">+          return -1;</span><br><span style="color: hsl(120, 100%, 40%);">+    }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span>  LOGPLCHAN(lchan, DL1C, LOGL_INFO, "Deactivating channel %s\n",</span><br><span>               rsl_chan_nr_str(chan_nr));</span><br><span> </span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-bts/+/25965">change 25965</a>. To unsubscribe, or for help writing mail filters, visit <a href="https://gerrit.osmocom.org/settings">settings</a>.</p><div itemscope itemtype="http://schema.org/EmailMessage"><div itemscope itemprop="action" itemtype="http://schema.org/ViewAction"><link itemprop="url" href="https://gerrit.osmocom.org/c/osmo-bts/+/25965"/><meta itemprop="name" content="View Change"/></div></div>

<div style="display:none"> Gerrit-Project: osmo-bts </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: I093e4d4e23b527b10bf5d6ff538460626c30a8f8 </div>
<div style="display:none"> Gerrit-Change-Number: 25965 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: pespin <pespin@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>