Re: [vpp-dev] Crash in BVI and Loopback interaction
From: vpp-dev@lists.fd.io on behalf of Pim van Pelt via lists.fd.io Date: Sunday, 27 March 2022 at 14:01 To: Stanislav Zaikin Cc: vpp-dev Subject: Re: [vpp-dev] Crash in BVI and Loopback interaction Hoi Stanislav, Thanks for the response. As I noted in my original email, I am aware that loopbacks work as BVI members, but since they are there (and have a whole device class dedicated to them!) I was hoping to 1. get some historical context on the need/differences between BVI and Loopback devices, and I’m guilty there. My rationale for introducing the BVI interface was to have an interface type dedicated to, and optimised for, the L2 function, rather than overloading the loopback type, which in the L3 world has a very different purpose. However, since there is a large installed base using the loopback for the purpose of l2, its L2 functions were never deprecated. /neale (b) get to the bottom of this bug and fix it :) I can certainly work around the bug for now by dedicating a set of loopback interfaces and avoiding the use of BVIs, for now. groet, Pim On Sun, Mar 27, 2022 at 12:43 PM Stanislav Zaikin mailto:zsta...@gmail.com>> wrote: Hi Pim, Well, I wasn't aware of "bvi ..." commands. Anyway, usually I go with something like: create loopback interface instance 20 set interface state loop20 up create bridge-domain 20 learn 1 forward 1 flood 1 arp-term 1 arp-ufwd 0 set interface l2 bridge loop20 20 bvi On Sun, 27 Mar 2022 at 00:41, Pim van Pelt mailto:p...@ipng.nl>> wrote: Hoi, I've noticed that a pattern of 'create loopback; delete loopback; create bvi' as well as 'create bvi; delete bvi; create loopback' makes VPP at HEAD unhappy. I've actually long since wondered what the difference is between BVI and Loopback interface types, other than the BVI plumbing lives in l2/l2_bvi.c and the loopback lives in ethernet/interface.c their _use_ seems very similar if not identical. I understand that BVIs are used in bridges, but a loopback in practice serves that purpose equally well. I assume the issue is in the bvi/loop deletion not the creation, but I stared at this for an hour or so and could not understand it. Can somebody more knowledgeable help me out ? Take the following simple repro to crash VPP. The assertion in noce.c:194 fails in both cases: 1) create loop after bvi: DBGvpp# show version vpp v22.06-rc0~268-g4859d8d8e built by pim on hippo at 2022-03-23T19:23:53 DBGvpp# bvi create instance 0 bvi0 DBGvpp# bvi delete bvi0 DBGvpp# create loopback interface instance 0 0: /home/pim/src/vpp/src/vlib/node.c:194 (vlib_node_add_next_with_slot) assertion `slot == p[0]' fails Thread 1 "vpp_main" received signal SIGABRT, Aborted. __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 50 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory. (gdb) bt #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #1 0x769de859 in __GI_abort () at abort.c:79 #2 0x004072f3 in os_panic () at /home/pim/src/vpp/src/vpp/vnet/main.c:413 #3 0x76d2ebc9 in debugger () at /home/pim/src/vpp/src/vppinfra/error.c:84 #4 0x76d2e92d in _clib_error (how_to_die=2, function_name=0x0, line_number=0, fmt=0x76f3b19c "%s:%d (%s) assertion `%s' fails") at /home/pim/src/vpp/src/vppinfra/error.c:143 #5 0x76ea462b in vlib_node_add_next_with_slot (vm=0x7fff96800740, node_index=696, next_node_index=648, slot=2) at /home/pim/src/vpp/src/vlib/node.c:194 #6 0x76ea61d8 in vlib_node_add_named_next_with_slot (vm=0x7fff96800740, node=696, name=0x77cc7c86 "l2-input", slot=2) at /home/pim/src/vpp/src/vlib/node.c:267 #7 0x770d5ce5 in vnet_create_loopback_interface (sw_if_indexp=0x7fff515421e8, mac_address=0x7fff515421e2 "", is_specified=1 '\001', user_instance=0) at /home/pim/src/vpp/src/vnet/ethernet/interface.c:890 #8 0x770d98df in create_simulated_ethernet_interfaces (vm=0x7fff96800740, input=0x7fff51542e40, cmd=0x7fff99b88088) at /home/pim/src/vpp/src/vnet/ethernet/interface.c:930 #9 0x76e681d4 in vlib_cli_dispatch_sub_commands (vm=0x7fff96800740, cm=0x4312e0 , input=0x7fff51542e40, parent_command_index=1146) at /home/pim/src/vpp/src/vlib/cli.c:592 #10 0x76e67f4e in vlib_cli_dispatch_sub_commands (vm=0x7fff96800740, cm=0x4312e0 , input=0x7fff51542e40, parent_command_index=33) at /home/pim/src/vpp/src/vlib/cli.c:549 #11 0x76e67f4e in vlib_cli_dispatch_sub_commands (vm=0x7fff96800740, cm=0x4312e0 , input=0x7fff51542e40, parent_command_index=0) at /home/pim/src/vpp/src/vlib/cli.c:549 #12 0x76e66e98 in vlib_cli_input (vm=0x7fff96800740, input=0x7fff51542e40, function=0x76ef2c40 , function_arg=0) at /home/pim/src/vpp/src/vlib/cli.c:695 #13 0x76ef48dd in unix_cli_process_input (cm=0x76f69748 , cli_file_index=0) at /home/pim/src/vpp/src/vlib/
Re: [vpp-dev] Crash in BVI and Loopback interaction
Hoi Stanislav, Thanks for the response. As I noted in my original email, I am aware that loopbacks work as BVI members, but since they are there (and have a whole device class dedicated to them!) I was hoping to (a) get some historical context on the need/differences between BVI and Loopback devices, and (b) get to the bottom of this bug and fix it :) I can certainly work around the bug for now by dedicating a set of loopback interfaces and avoiding the use of BVIs, for now. groet, Pim On Sun, Mar 27, 2022 at 12:43 PM Stanislav Zaikin wrote: > Hi Pim, > > Well, I wasn't aware of "bvi ..." commands. Anyway, usually I go with > something like: > > create loopback interface instance 20 > set interface state loop20 up > create bridge-domain 20 learn 1 forward 1 flood 1 arp-term 1 arp-ufwd 0 > set interface l2 bridge loop20 20 bvi > > On Sun, 27 Mar 2022 at 00:41, Pim van Pelt wrote: > >> Hoi, >> >> I've noticed that a pattern of 'create loopback; delete loopback; create >> bvi' as well as 'create bvi; delete bvi; create loopback' makes VPP at HEAD >> unhappy. >> I've actually long since wondered what the difference is between BVI and >> Loopback interface types, other than the BVI plumbing lives in l2/l2_bvi.c >> and the loopback lives in ethernet/interface.c their _use_ seems very >> similar if not identical. I understand that BVIs are used in bridges, but a >> loopback in practice serves that purpose equally well. >> >> I assume the issue is in the bvi/loop deletion not the creation, but I >> stared at this for an hour or so and could not understand it. Can somebody >> more knowledgeable help me out ? >> Take the following simple repro to crash VPP. The assertion in noce.c:194 >> fails in both cases: >> >> *1) create loop after bvi:* >> DBGvpp# show version >> vpp v22.06-rc0~268-g4859d8d8e built by pim on hippo at 2022-03-23T19:23:53 >> DBGvpp# bvi create instance 0 >> bvi0 >> DBGvpp# bvi delete bvi0 >> DBGvpp# create loopback interface instance 0 >> >> *0: /home/pim/src/vpp/src/vlib/node.c:194 (vlib_node_add_next_with_slot) >> assertion `slot == p[0]' fails* >> Thread 1 "vpp_main" received signal SIGABRT, Aborted. >> __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 >> 50 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory. >> (gdb) bt >> #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 >> #1 0x769de859 in __GI_abort () at abort.c:79 >> #2 0x004072f3 in os_panic () at >> /home/pim/src/vpp/src/vpp/vnet/main.c:413 >> #3 0x76d2ebc9 in debugger () at >> /home/pim/src/vpp/src/vppinfra/error.c:84 >> #4 0x76d2e92d in _clib_error (how_to_die=2, function_name=0x0, >> line_number=0, fmt=0x76f3b19c "%s:%d (%s) assertion `%s' fails") >> at /home/pim/src/vpp/src/vppinfra/error.c:143 >> #5 0x76ea462b in vlib_node_add_next_with_slot >> (vm=0x7fff96800740, node_index=696, next_node_index=648, slot=2) >> at /home/pim/src/vpp/src/vlib/node.c:194 >> #6 0x76ea61d8 in vlib_node_add_named_next_with_slot >> (vm=0x7fff96800740, node=696, name=0x77cc7c86 "l2-input", slot=2) >> at /home/pim/src/vpp/src/vlib/node.c:267 >> #7 0x770d5ce5 in vnet_create_loopback_interface >> (sw_if_indexp=0x7fff515421e8, mac_address=0x7fff515421e2 "", is_specified=1 >> '\001', >> user_instance=0) at >> /home/pim/src/vpp/src/vnet/ethernet/interface.c:890 >> #8 0x770d98df in create_simulated_ethernet_interfaces >> (vm=0x7fff96800740, input=0x7fff51542e40, cmd=0x7fff99b88088) >> at /home/pim/src/vpp/src/vnet/ethernet/interface.c:930 >> #9 0x76e681d4 in vlib_cli_dispatch_sub_commands >> (vm=0x7fff96800740, cm=0x4312e0 , >> input=0x7fff51542e40, >> parent_command_index=1146) at /home/pim/src/vpp/src/vlib/cli.c:592 >> #10 0x76e67f4e in vlib_cli_dispatch_sub_commands >> (vm=0x7fff96800740, cm=0x4312e0 , >> input=0x7fff51542e40, >> parent_command_index=33) at /home/pim/src/vpp/src/vlib/cli.c:549 >> #11 0x76e67f4e in vlib_cli_dispatch_sub_commands >> (vm=0x7fff96800740, cm=0x4312e0 , >> input=0x7fff51542e40, >> parent_command_index=0) at /home/pim/src/vpp/src/vlib/cli.c:549 >> #12 0x76e66e98 in vlib_cli_input (vm=0x7fff96800740, >> input=0x7fff51542e40, function=0x76ef2c40 , >> function_arg=0) >> at /home/pim/src/vpp/src/vlib/cli.c:695 >> #13 0x76ef48dd in unix_cli_process_input (cm=0x76f69748 >> , cli_file_index=0) at >> /home/pim/src/vpp/src/vlib/unix/cli.c:2617 >> #14 0x76ef1cb1 in unix_cli_process (vm=0x7fff96800740, >> rt=0x7fff9bc4ea80, f=0x0) at /home/pim/src/vpp/src/vlib/unix/cli.c:2746 >> #15 0x76e9f26d in vlib_process_bootstrap (_a=140735646532920) at >> /home/pim/src/vpp/src/vlib/main.c:1220 >> #16 0x76d47e08 in clib_calljmp () at >> /home/pim/src/vpp/src/vppinfra/longjmp.S:123 >> #17 0x7fff92380530 in ?? () >> #18 0x76e9eb3f in vlib_process_startup (vm=0x1, p=0x8, >> f=0x7fff968008b0)
Re: [vpp-dev] Crash in BVI and Loopback interaction
Hi Pim, Well, I wasn't aware of "bvi ..." commands. Anyway, usually I go with something like: create loopback interface instance 20 set interface state loop20 up create bridge-domain 20 learn 1 forward 1 flood 1 arp-term 1 arp-ufwd 0 set interface l2 bridge loop20 20 bvi On Sun, 27 Mar 2022 at 00:41, Pim van Pelt wrote: > Hoi, > > I've noticed that a pattern of 'create loopback; delete loopback; create > bvi' as well as 'create bvi; delete bvi; create loopback' makes VPP at HEAD > unhappy. > I've actually long since wondered what the difference is between BVI and > Loopback interface types, other than the BVI plumbing lives in l2/l2_bvi.c > and the loopback lives in ethernet/interface.c their _use_ seems very > similar if not identical. I understand that BVIs are used in bridges, but a > loopback in practice serves that purpose equally well. > > I assume the issue is in the bvi/loop deletion not the creation, but I > stared at this for an hour or so and could not understand it. Can somebody > more knowledgeable help me out ? > Take the following simple repro to crash VPP. The assertion in noce.c:194 > fails in both cases: > > *1) create loop after bvi:* > DBGvpp# show version > vpp v22.06-rc0~268-g4859d8d8e built by pim on hippo at 2022-03-23T19:23:53 > DBGvpp# bvi create instance 0 > bvi0 > DBGvpp# bvi delete bvi0 > DBGvpp# create loopback interface instance 0 > > *0: /home/pim/src/vpp/src/vlib/node.c:194 (vlib_node_add_next_with_slot) > assertion `slot == p[0]' fails* > Thread 1 "vpp_main" received signal SIGABRT, Aborted. > __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 > 50 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory. > (gdb) bt > #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 > #1 0x769de859 in __GI_abort () at abort.c:79 > #2 0x004072f3 in os_panic () at > /home/pim/src/vpp/src/vpp/vnet/main.c:413 > #3 0x76d2ebc9 in debugger () at > /home/pim/src/vpp/src/vppinfra/error.c:84 > #4 0x76d2e92d in _clib_error (how_to_die=2, function_name=0x0, > line_number=0, fmt=0x76f3b19c "%s:%d (%s) assertion `%s' fails") > at /home/pim/src/vpp/src/vppinfra/error.c:143 > #5 0x76ea462b in vlib_node_add_next_with_slot (vm=0x7fff96800740, > node_index=696, next_node_index=648, slot=2) > at /home/pim/src/vpp/src/vlib/node.c:194 > #6 0x76ea61d8 in vlib_node_add_named_next_with_slot > (vm=0x7fff96800740, node=696, name=0x77cc7c86 "l2-input", slot=2) > at /home/pim/src/vpp/src/vlib/node.c:267 > #7 0x770d5ce5 in vnet_create_loopback_interface > (sw_if_indexp=0x7fff515421e8, mac_address=0x7fff515421e2 "", is_specified=1 > '\001', > user_instance=0) at /home/pim/src/vpp/src/vnet/ethernet/interface.c:890 > #8 0x770d98df in create_simulated_ethernet_interfaces > (vm=0x7fff96800740, input=0x7fff51542e40, cmd=0x7fff99b88088) > at /home/pim/src/vpp/src/vnet/ethernet/interface.c:930 > #9 0x76e681d4 in vlib_cli_dispatch_sub_commands > (vm=0x7fff96800740, cm=0x4312e0 , > input=0x7fff51542e40, > parent_command_index=1146) at /home/pim/src/vpp/src/vlib/cli.c:592 > #10 0x76e67f4e in vlib_cli_dispatch_sub_commands > (vm=0x7fff96800740, cm=0x4312e0 , > input=0x7fff51542e40, > parent_command_index=33) at /home/pim/src/vpp/src/vlib/cli.c:549 > #11 0x76e67f4e in vlib_cli_dispatch_sub_commands > (vm=0x7fff96800740, cm=0x4312e0 , > input=0x7fff51542e40, > parent_command_index=0) at /home/pim/src/vpp/src/vlib/cli.c:549 > #12 0x76e66e98 in vlib_cli_input (vm=0x7fff96800740, > input=0x7fff51542e40, function=0x76ef2c40 , > function_arg=0) > at /home/pim/src/vpp/src/vlib/cli.c:695 > #13 0x76ef48dd in unix_cli_process_input (cm=0x76f69748 > , cli_file_index=0) at > /home/pim/src/vpp/src/vlib/unix/cli.c:2617 > #14 0x76ef1cb1 in unix_cli_process (vm=0x7fff96800740, > rt=0x7fff9bc4ea80, f=0x0) at /home/pim/src/vpp/src/vlib/unix/cli.c:2746 > #15 0x76e9f26d in vlib_process_bootstrap (_a=140735646532920) at > /home/pim/src/vpp/src/vlib/main.c:1220 > #16 0x76d47e08 in clib_calljmp () at > /home/pim/src/vpp/src/vppinfra/longjmp.S:123 > #17 0x7fff92380530 in ?? () > #18 0x76e9eb3f in vlib_process_startup (vm=0x1, p=0x8, > f=0x7fff968008b0) at /home/pim/src/vpp/src/vlib/main.c:1245 > #19 0x7fff96800740 in ?? () > #20 0x7fff923805c0 in ?? () > #21 0x76eff104 in vlib_process_signal_event (vm= variable: Cannot access memory at address 0x2a7>, > node_index= 0x29f>, > type_opaque= 0x297>, > data=) > at /home/pim/src/vpp/src/vlib/node_funcs.h:1025 > Backtrace stopped: previous frame inner to this frame (corrupt stack?) > > *2) Create bvi after loop:* > DBGvpp# show version > vpp v22.06-rc0~268-g4859d8d8e built by pim on hippo at 2022-03-23T19:23:53 > DBGvpp# create loopback > loop0 > DBGvpp# delete loopback interface intfc loop0 > DBGvpp# bvi create > *0:
[vpp-dev] Crash in BVI and Loopback interaction
Hoi, I've noticed that a pattern of 'create loopback; delete loopback; create bvi' as well as 'create bvi; delete bvi; create loopback' makes VPP at HEAD unhappy. I've actually long since wondered what the difference is between BVI and Loopback interface types, other than the BVI plumbing lives in l2/l2_bvi.c and the loopback lives in ethernet/interface.c their _use_ seems very similar if not identical. I understand that BVIs are used in bridges, but a loopback in practice serves that purpose equally well. I assume the issue is in the bvi/loop deletion not the creation, but I stared at this for an hour or so and could not understand it. Can somebody more knowledgeable help me out ? Take the following simple repro to crash VPP. The assertion in noce.c:194 fails in both cases: *1) create loop after bvi:* DBGvpp# show version vpp v22.06-rc0~268-g4859d8d8e built by pim on hippo at 2022-03-23T19:23:53 DBGvpp# bvi create instance 0 bvi0 DBGvpp# bvi delete bvi0 DBGvpp# create loopback interface instance 0 *0: /home/pim/src/vpp/src/vlib/node.c:194 (vlib_node_add_next_with_slot) assertion `slot == p[0]' fails* Thread 1 "vpp_main" received signal SIGABRT, Aborted. __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 50 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory. (gdb) bt #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #1 0x769de859 in __GI_abort () at abort.c:79 #2 0x004072f3 in os_panic () at /home/pim/src/vpp/src/vpp/vnet/main.c:413 #3 0x76d2ebc9 in debugger () at /home/pim/src/vpp/src/vppinfra/error.c:84 #4 0x76d2e92d in _clib_error (how_to_die=2, function_name=0x0, line_number=0, fmt=0x76f3b19c "%s:%d (%s) assertion `%s' fails") at /home/pim/src/vpp/src/vppinfra/error.c:143 #5 0x76ea462b in vlib_node_add_next_with_slot (vm=0x7fff96800740, node_index=696, next_node_index=648, slot=2) at /home/pim/src/vpp/src/vlib/node.c:194 #6 0x76ea61d8 in vlib_node_add_named_next_with_slot (vm=0x7fff96800740, node=696, name=0x77cc7c86 "l2-input", slot=2) at /home/pim/src/vpp/src/vlib/node.c:267 #7 0x770d5ce5 in vnet_create_loopback_interface (sw_if_indexp=0x7fff515421e8, mac_address=0x7fff515421e2 "", is_specified=1 '\001', user_instance=0) at /home/pim/src/vpp/src/vnet/ethernet/interface.c:890 #8 0x770d98df in create_simulated_ethernet_interfaces (vm=0x7fff96800740, input=0x7fff51542e40, cmd=0x7fff99b88088) at /home/pim/src/vpp/src/vnet/ethernet/interface.c:930 #9 0x76e681d4 in vlib_cli_dispatch_sub_commands (vm=0x7fff96800740, cm=0x4312e0 , input=0x7fff51542e40, parent_command_index=1146) at /home/pim/src/vpp/src/vlib/cli.c:592 #10 0x76e67f4e in vlib_cli_dispatch_sub_commands (vm=0x7fff96800740, cm=0x4312e0 , input=0x7fff51542e40, parent_command_index=33) at /home/pim/src/vpp/src/vlib/cli.c:549 #11 0x76e67f4e in vlib_cli_dispatch_sub_commands (vm=0x7fff96800740, cm=0x4312e0 , input=0x7fff51542e40, parent_command_index=0) at /home/pim/src/vpp/src/vlib/cli.c:549 #12 0x76e66e98 in vlib_cli_input (vm=0x7fff96800740, input=0x7fff51542e40, function=0x76ef2c40 , function_arg=0) at /home/pim/src/vpp/src/vlib/cli.c:695 #13 0x76ef48dd in unix_cli_process_input (cm=0x76f69748 , cli_file_index=0) at /home/pim/src/vpp/src/vlib/unix/cli.c:2617 #14 0x76ef1cb1 in unix_cli_process (vm=0x7fff96800740, rt=0x7fff9bc4ea80, f=0x0) at /home/pim/src/vpp/src/vlib/unix/cli.c:2746 #15 0x76e9f26d in vlib_process_bootstrap (_a=140735646532920) at /home/pim/src/vpp/src/vlib/main.c:1220 #16 0x76d47e08 in clib_calljmp () at /home/pim/src/vpp/src/vppinfra/longjmp.S:123 #17 0x7fff92380530 in ?? () #18 0x76e9eb3f in vlib_process_startup (vm=0x1, p=0x8, f=0x7fff968008b0) at /home/pim/src/vpp/src/vlib/main.c:1245 #19 0x7fff96800740 in ?? () #20 0x7fff923805c0 in ?? () #21 0x76eff104 in vlib_process_signal_event (vm=, node_index=, type_opaque=, data=) at /home/pim/src/vpp/src/vlib/node_funcs.h:1025 Backtrace stopped: previous frame inner to this frame (corrupt stack?) *2) Create bvi after loop:* DBGvpp# show version vpp v22.06-rc0~268-g4859d8d8e built by pim on hippo at 2022-03-23T19:23:53 DBGvpp# create loopback loop0 DBGvpp# delete loopback interface intfc loop0 DBGvpp# bvi create *0: /home/pim/src/vpp/src/vlib/node.c:194 (vlib_node_add_next_with_slot) assertion `slot == p[0]' fails * Thread 1 "vpp_main" received signal SIGABRT, Aborted. __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 50 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory. (gdb) bt #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #1 0x769de859 in __GI_abort () at abort.c:79 #2 0x004072f3 in os_panic () at /home/pim/src/vpp/src/vpp/vnet/main.c:413 #3 0x76d2ebc9 in debugger () at
