Question
Why does a crash that appears to be the same as already seen crashes get listed separately in the crash list?
Answer
Analyzing the following two sessmgr process crashes, one might conclude they are the same and wonder why the system has listed them separately in the crash list. On close observation, note that there is a slight difference in the address in the left most column of the show crash number X output, which is the point in the code where the function on that same line calls the function listed above it (snx_hsgwdrv_send_add_sub_session() in this example).
******** show crash list *******
Friday October 03 18:25:28 UTC 2014
== ==== ======= ========== =========== ================
# Time Process Card/CPU/ SW HW_SER_NUM
PID VERSION SMC / Crash Card
== ==== ======= ========== =========== ================
1 2013-Nov-30+05:08:15 sessmgr 07/0/04317 14.1(50455) SAD160200KX/PLB31103947
2 2014-Jun-06+16:45:44 sessmgr 05/0/06002 15.0(53417) SAD160200KX/PLB37108248
3 2014-Oct-02+08:08:03 sessmgr 15/0/06059 16.1(55894) SAD160200KX/PLB42100206
4 2014-Oct-03+03:02:00 sessmgr 02/0/05979 16.1(55894) SAD160200KX/PLB38108892
Total Crashes : 12
********************* CRASH #03 ***********************
SW Version : 16.1(55894)
Similar Crash Count : 1
Time of First Crash : 2014-Oct-02+08:08:03
Fatal Signal 11: Segmentation fault
PC: [0534bf6d/X] sessmgr_imsa_update_ip_addr()
Faulty address: (nil)
Signal from: kernel
Signal detail: address not mapped to object
Process: card=15 cpu=0 arch=X pid=6059 cpu=~0% argv0=sessmgr
Crash time: 2014-Oct-02+08:08:03 UTC
Recent errno: 11 Resource temporarily unavailable
Stack (64280@0xfffee000):
[0534bf6d/X] sessmgr_imsa_update_ip_addr() sp=0xfffee7d8
[0365f41d/X] sessmgr_mag_handle_add_sub_session() sp=0xfffee928
[036f3a66/X] smgr_fsm_state_connected() sp=0xffffaff8
[03681397/X] smgr_callline_fsm() sp=0xffffb098
[05d8089b/X] sessmgr_app_svr_event_control_dispatch() sp=0xffffb628
[0461986b/X] snx_hsgwdrv_send_add_sub_session() sp=0xffffbba8
[0461dfa6/X] snx_hsgwdrv_fsm() sp=0xffffbd68
[04621cba/X] snx_hsgwdrv_event_control_dispatch() sp=0xffffbdf8
[046032b6/X] snx_pppdrv_notify_vsncp_up() sp=0xffffbe28
[046036ac/X] snx_pppdrv_fsm_state_connected() sp=0xffffbe68
[0460446a/X] snx_pppdrv_fsm() sp=0xffffbfe8
[04608e0a/X] mlppp_event_indication() sp=0xffffc328
[0514d1ae/X] VSNCPNotify() sp=0xffffc388
[0515e88d/X] NCPRunStateActions() sp=0xffffc3e8
[0515ae53/X] ProcessConfigData() sp=0xffffc488
[0515b9ec/X] ProcessNCP() sp=0xffffc4b8
[05144931/X] MLPSwitch() sp=0xffffc558
[05167c5c/X] PPPSwitch() sp=0xffffc768
[05e47033/X] DoSomethingWithData.isra.149() sp=0xffffcc78
[05e5a1ea/X] sessmgr_med_rp_a10_data_receive() sp=0xffffd3f8
[0600880d/X] sessmgr_med_data_receive() sp=0xffffd598
[0ac565ac/X] sn_epoll_run_events() sp=0xffffd5e8
[0ac5aca8/X] sn_loop_run() sp=0xffffda98
[0a9fd96d/X] main() sp=0xffffdb08
********************* CRASH #04 ***********************
SW Version : 16.1(55894)
Similar Crash Count : 9
Time of First Crash : 2014-Oct-02+07:31:35
Fatal Signal 11: Segmentation fault
PC: [0534bf6d/X] sessmgr_imsa_update_ip_addr()
Faulty address: (nil)
Signal from: kernel
Signal detail: address not mapped to object
Process: card=2 cpu=0 arch=X pid=5979 cpu=~4% argv0=sessmgr
Crash time: 2014-Oct-03+03:02:00 UTC
Recent errno: 11 Resource temporarily unavailable
Stack (64280@0xfffee000):
[0534bf6d/X] sessmgr_imsa_update_ip_addr() sp=0xfffee7d8
[0365f41d/X] sessmgr_mag_handle_add_sub_session() sp=0xfffee928
[036f3a66/X] smgr_fsm_state_connected() sp=0xffffaff8
[03681397/X] smgr_callline_fsm() sp=0xffffb098
[05d8089b/X] sessmgr_app_svr_event_control_dispatch() sp=0xffffb628
[0461986b/X] snx_hsgwdrv_send_add_sub_session() sp=0xffffbba8
[0461dd33/X] snx_hsgwdrv_fsm() sp=0xffffbd68
[04621cba/X] snx_hsgwdrv_event_control_dispatch() sp=0xffffbdf8
[046032b6/X] snx_pppdrv_notify_vsncp_up() sp=0xffffbe28
[046036ac/X] snx_pppdrv_fsm_state_connected() sp=0xffffbe68
[0460446a/X] snx_pppdrv_fsm() sp=0xffffbfe8
[04608e0a/X] mlppp_event_indication() sp=0xffffc328
[0514d1ae/X] VSNCPNotify() sp=0xffffc388
[0515e88d/X] NCPRunStateActions() sp=0xffffc3e8
[0515ae53/X] ProcessConfigData() sp=0xffffc488
[0515b9ec/X] ProcessNCP() sp=0xffffc4b8
[05144931/X] MLPSwitch() sp=0xffffc558
[05167c5c/X] PPPSwitch() sp=0xffffc768
[05e47033/X] DoSomethingWithData.isra.149() sp=0xffffcc78
[05e5a1ea/X] sessmgr_med_rp_a10_data_receive() sp=0xffffd3f8
[0600880d/X] sessmgr_med_data_receive() sp=0xffffd598
[0ac565ac/X] sn_epoll_run_events() sp=0xffffd5e8
[0ac5aca8/X] sn_loop_run() sp=0xffffda98
[0a9fd96d/X] main() sp=0xffffdb08
The point here is that the crashes are listed as separate crashes due to the fact that the calls to functions are made from different places in the code.
In these cases, open up a case with Cisco to confirm whether or not the root cause for the crashes is the same for such scenarios just in case separate fixes are needed for the different code flows.
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