Bug 230655 - vlan(4) holds non-sleepable locks around driver ioctls
Summary: vlan(4) holds non-sleepable locks around driver ioctls
Status: Closed DUPLICATE of bug 230510
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: CURRENT
Hardware: Any Any
: --- Affects Many People
Assignee: freebsd-net (Nobody)
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2018-08-15 18:41 UTC by Navdeep Parhar
Modified: 2018-09-24 19:06 UTC (History)
3 users (show)

See Also:

Attachments
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Navdeep Parhar freebsd_committer freebsd_triage 2018-08-15 18:41:28 UTC 
There was recent work in the stack to not hold non-sleepable locks around
NIC driver ioctls.  It seems that vlan(4) still does.


begin_synchronized_op with the following non-sleepable locks held:
exclusive rm vlan (vlan) r = 0 (0xfffff8000459e388) locked @ /root/ws/head/sys/net/if_vlan.c:1917
shared rm vlan_rm (vlan_rm) r = 0 (0xffffffff827e9480) locked @ /root/ws/head/sys/net/if_vlan.c:1914
stack backtrace:
#0 0xffffffff81238331 at witness_debugger+0xf1
#1 0xffffffff812398a8 at witness_warn+0x3b8
#2 0xffffffff8326296c at begin_synchronized_op+0x6c
#3 0xffffffff83275b72 at cxgbe_ioctl+0x382
#4 0xffffffff8132e24a at if_addmulti+0x38a
#5 0xffffffff8134ebf4 at vlan_setmulti+0x384
#6 0xffffffff8134dbc7 at vlan_ioctl+0x797
#7 0xffffffff8132e24a at if_addmulti+0x38a
#8 0xffffffff814181c8 at in_getmulti+0x178
#9 0xffffffff81417ee8 at in_joingroup_locked+0xb8
#10 0xffffffff81417e0a at in_joingroup+0x4a
#11 0xffffffff8140f326 at in_aifaddr_ioctl+0xe46
#12 0xffffffff8140d6f8 at in_control+0x228
#13 0xffffffff8132abdd at ifioctl+0x7fd
#14 0xffffffff8124e4ce at soo_ioctl+0x79e
#15 0xffffffff8124053c at fo_ioctl+0x4c
#16 0xffffffff81240291 at kern_ioctl+0x361
#17 0xffffffff8123fe6a at sys_ioctl+0x2ea
Comment 1 Eric Joyner freebsd_committer freebsd_triage 2018-09-18 20:52:52 UTC 
We also see this when using iflib drivers:

lock order reversal: (sleepable after non-sleepable)
  1st 0xfffff807b4884d08 vlan (vlan) @ /usr/src/sys/net/if_vlan.c:1931
  2nd 0xfffff80549c87560 iflib ctx lock (iflib ctx lock) @ /usr/src/sys/net/iflib.c:4218
 stack backtrace:
 #0 0xffffffff80bc1c83 at witness_debugger+0x73
 #1 0xffffffff80bc19d3 at witness_checkorder+0xab3
 #2 0xffffffff80b62e68 at _sx_xlock+0x68
 #3 0xffffffff80c7a2bc at iflib_if_ioctl+0x8c
 #4 0xffffffff80c5beca at if_addmulti+0x24a
 #5 0xffffffff80c6c9c6 at vlan_setmulti+0x196
 #6 0xffffffff80c6bb89 at vlan_ioctl+0xa9
 #7 0xffffffff80c5beca at if_addmulti+0x24a
 #8 0xffffffff80ce0075 at in_joingroup_locked+0x235
 #9 0xffffffff80cdfe12 at in_joingroup+0x42
 #10 0xffffffff80cdb358 at in_control+0xb08
 #11 0xffffffff80c5af73 at ifioctl+0x1853
 #12 0xffffffff80bc6bba at kern_ioctl+0x2ba
 #13 0xffffffff80bc688e at sys_ioctl+0x15e
 #14 0xffffffff8102ce0c at amd64_syscall+0x28c
 #15 0xffffffff810095fd at fast_syscall_common+0x101
Comment 2 Navdeep Parhar freebsd_committer freebsd_triage 2018-09-24 19:06:09 UTC 
I believe this is fixed in r338850.

*** This bug has been marked as a duplicate of bug 230510 ***