freebsd kernel with SKQ
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royger 674010a405 xen-netfront: fix two hotplug related issues
This patch fixes two issues seen on hot-unplug. The first one is a panic
caused by calling ether_ifdetach after freeing the internal netfront queue
structures. ether_ifdetach will call xn_qflush, and this needs to be done
before freeing the queues. This prevents the following panic:

Fatal trap 9: general protection fault while in kernel mode
cpuid = 2; apic id = 04
instruction pointer	= 0x20:0xffffffff80b1687f
stack pointer	        = 0x28:0xfffffe009239e770
frame pointer	        = 0x28:0xfffffe009239e780
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 0 (thread taskq)
[ thread pid 0 tid 100015 ]
Stopped at      strlen+0x1f:    movq    (%rcx),%rax
db> bt
Tracing pid 0 tid 100015 td 0xfffff800038a6000
strlen() at strlen+0x1f/frame 0xfffffe009239e780
kvprintf() at kvprintf+0xfa0/frame 0xfffffe009239e890
vsnprintf() at vsnprintf+0x31/frame 0xfffffe009239e8b0
kassert_panic() at kassert_panic+0x5a/frame 0xfffffe009239e920
__mtx_lock_flags() at __mtx_lock_flags+0x164/frame 0xfffffe009239e970
xn_qflush() at xn_qflush+0x59/frame 0xfffffe009239e9b0
if_detach() at if_detach+0x17e/frame 0xfffffe009239ea10
netif_free() at netif_free+0x97/frame 0xfffffe009239ea30
netfront_detach() at netfront_detach+0x11/frame 0xfffffe009239ea40
[...]

Another panic can be triggered by hot-plugging a NIC:

Fatal trap 18: integer divide fault while in kernel mode
cpuid = 0; apic id = 00
instruction pointer	= 0x20:0xffffffff80902203
stack pointer	        = 0x28:0xfffffe00508d3660
frame pointer	        = 0x28:0xfffffe00508d36a0
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 2960 (ifconfig)
[ thread pid 2960 tid 100088 ]
Stopped at      xn_txq_mq_start+0x33:   divl    %esi,%eax
db> bt
Tracing pid 2960 tid 100088 td 0xfffff8000850aa00
xn_txq_mq_start() at xn_txq_mq_start+0x33/frame 0xfffffe00508d36a0
ether_output() at ether_output+0x570/frame 0xfffffe00508d3720
arprequest() at arprequest+0x433/frame 0xfffffe00508d3820
arp_ifinit() at arp_ifinit+0x49/frame 0xfffffe00508d3850
xn_ioctl() at xn_ioctl+0x1a2/frame 0xfffffe00508d3890
in_control() at in_control+0x882/frame 0xfffffe00508d3910
ifioctl() at ifioctl+0xda1/frame 0xfffffe00508d39a0
kern_ioctl() at kern_ioctl+0x246/frame 0xfffffe00508d3a00
sys_ioctl() at sys_ioctl+0x171/frame 0xfffffe00508d3ae0
amd64_syscall() at amd64_syscall+0x2db/frame 0xfffffe00508d3bf0
Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfffffe00508d3bf0
--- syscall (54, FreeBSD ELF64, sys_ioctl), rip = 0x8011e185a, rsp =
0x7fffffffe478, rbp = 0x7fffffffe4c0 ---

This is caused by marking the driver as active before it's fully
initialized, and thus calling xn_txq_mq_start with num_queues set to 0.

Reviewed by:		Wei Liu <wei.liu2@citrix.com>
Sponsored by:		Citrix Systems R&D
Differential revision:	https://reviews.freebsd.org/D6646
2016-06-02 11:18:02 +00:00
bin ps(1): Expand variables to match expanded fields 2016-06-01 19:54:05 +00:00
cddl Fix missing space in mandoc syntax 2016-06-01 06:18:34 +00:00
contrib Import NetBSD's blacklist source from vendor tree 2016-06-01 22:04:10 +00:00
crypto libkrb5: Fix potential double-free 2016-05-11 23:25:59 +00:00
etc Revert r301137 and r301163, and implement a correct fix 2016-06-01 20:44:28 +00:00
gnu gcc42: Fix minor C99 parse bug 2016-05-27 03:40:52 +00:00
include Fix prototype of dbm_open(). 2016-05-31 18:32:57 +00:00
kerberos5 Remove the old depend (mkdep) code and make FAST_DEPEND the one true way. 2016-03-30 23:50:23 +00:00
lib thr_*(2): Add xrefs to what libthr implements using each syscall. 2016-06-01 21:58:13 +00:00
libexec Revert r301137 and r301163, and implement a correct fix 2016-06-01 20:44:28 +00:00
release Turn off nfsv4acls for arm/armv6 builds, which has an impact 2016-06-01 04:18:55 +00:00
rescue DIRDEPS_BUILD: Fix and hookup rescue/rescue to the build. 2016-05-26 23:20:40 +00:00
sbin Address feedback from hrs@ re: r301059 (ifconfig subnet mask) 2016-06-02 03:16:02 +00:00
secure Regen x86 assembly files for r299480. 2016-05-11 20:11:21 +00:00
share Add myself as src commiter. 2016-06-01 23:20:32 +00:00
sys xen-netfront: fix two hotplug related issues 2016-06-02 11:18:02 +00:00
targets DIRDEPS_BUILD: Fix and hookup rescue/rescue to the build. 2016-05-26 23:20:40 +00:00
tests Always create loopback routes on every fib 2016-05-27 22:40:40 +00:00
tools Add more hacks to correct CLDR data 2016-05-29 22:27:42 +00:00
usr.bin sed(1): Fix a mismatch and sync with the OpenBSD's commit. 2016-06-01 16:53:02 +00:00
usr.sbin Revert r301137 and r301163, and implement a correct fix 2016-06-01 20:44:28 +00:00
.arcconfig Remove project.name which is a product of a bygone era. 2016-04-21 04:33:07 +00:00
.arclint phabricator related changes: 2015-04-20 20:33:22 +00:00
COPYRIGHT Bump copyright year. 2015-12-31 11:21:45 +00:00
LOCKS
MAINTAINERS Add myself to MAINTAINERS. 2016-03-14 16:27:43 +00:00
Makefile Make armv6 hard float abi by default. Kill armv6hf. 2016-05-18 06:01:18 +00:00
Makefile.inc1 GCC External: Revert r300886, r300904, r300917, r300918 2016-05-29 06:20:15 +00:00
Makefile.libcompat Libcompat: Swap CXX/CFLAGS. 2016-05-29 06:20:36 +00:00
ObsoleteFiles.inc Remove extraneous altq header files 2016-05-30 02:09:19 +00:00
README README: remove nonexistent 'games' directory. 2016-05-18 10:43:13 +00:00
UPDATING Fix typo from r300880 2016-05-27 22:44:33 +00:00

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