Setting vlan flags needlessly takes the exclusive VLAN_XLOCK(). If we have stacked vlan devices (i.e. QinQ) and we set vlan flags (e.g. IFF_PROMISC) we call rtnl_handle_ifevent() to send a notification about the interface. This ends up calling SIOCGIFMEDIA, which requires the VLAN_SLOCK(). Trying to take that one with the VLAN_XLOCK() held deadlocks us. There's no need for the exclusive lock though, as we're only accessing parent/trunk information, not modifying it, so a shared lock is sufficient. While here also add a test case for this issue. Backtrace: shared lock of (sx) vlan_sx @ /usr/src/sys/net/if_vlan.c:2192 while exclusively locked from /usr/src/sys/net/if_vlan.c:2307 panic: excl->share cpuid = 29 time = 1683873033 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe015d4ad4b0 vpanic() at vpanic+0x152/frame 0xfffffe015d4ad500 panic() at panic+0x43/frame 0xfffffe015d4ad560 witness_checkorder() at witness_checkorder+0xcb5/frame 0xfffffe015d4ad720 _sx_slock_int() at _sx_slock_int+0x67/frame 0xfffffe015d4ad760 vlan_ioctl() at vlan_ioctl+0xf8/frame 0xfffffe015d4ad7c0 dump_iface() at dump_iface+0x12f/frame 0xfffffe015d4ad840 rtnl_handle_ifevent() at rtnl_handle_ifevent+0xab/frame 0xfffffe015d4ad8c0 if_setflag() at if_setflag+0xf6/frame 0xfffffe015d4ad930 ifpromisc() at ifpromisc+0x2a/frame 0xfffffe015d4ad960 vlan_setflags() at vlan_setflags+0x60/frame 0xfffffe015d4ad990 vlan_ioctl() at vlan_ioctl+0x216/frame 0xfffffe015d4ad9f0 if_setflag() at if_setflag+0xe4/frame 0xfffffe015d4ada60 ifpromisc() at ifpromisc+0x2a/frame 0xfffffe015d4ada90 bridge_ioctl_add() at bridge_ioctl_add+0x499/frame 0xfffffe015d4adb10 bridge_ioctl() at bridge_ioctl+0x328/frame 0xfffffe015d4adbc0 ifioctl() at ifioctl+0x972/frame 0xfffffe015d4adcc0 kern_ioctl() at kern_ioctl+0x1fe/frame 0xfffffe015d4add30 sys_ioctl() at sys_ioctl+0x154/frame 0xfffffe015d4ade00 amd64_syscall() at amd64_syscall+0x140/frame 0xfffffe015d4adf30 fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe015d4adf30 --- syscall (54, FreeBSD ELF64, ioctl), rip = 0x22b0f0ef8d8a, rsp = 0x22b0ec63f2c8, rbp = 0x22b0ec63f380 --- KDB: enter: panic [ thread pid 5715 tid 101132 ] Sponsored by: Rubicon Communications, LLC ("Netgate") |
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---|---|---|
.cirrus-ci | ||
.github | ||
bin | ||
cddl | ||
contrib | ||
crypto | ||
etc | ||
gnu | ||
include | ||
kerberos5 | ||
lib | ||
libexec | ||
release | ||
rescue | ||
sbin | ||
secure | ||
share | ||
stand | ||
sys | ||
targets | ||
tests | ||
tools | ||
usr.bin | ||
usr.sbin | ||
.arcconfig | ||
.arclint | ||
.cirrus.yml | ||
.clang-format | ||
.git-blame-ignore-revs | ||
.gitattributes | ||
.gitignore | ||
CONTRIBUTING.md | ||
COPYRIGHT | ||
LOCKS | ||
MAINTAINERS | ||
Makefile | ||
Makefile.inc1 | ||
Makefile.libcompat | ||
Makefile.sys.inc | ||
ObsoleteFiles.inc | ||
README.md | ||
RELNOTES | ||
UPDATING |
FreeBSD Source:
This is the top level of the FreeBSD source directory.
FreeBSD is an operating system used to power modern servers, desktops, and embedded platforms. A large community has continually developed it for more than thirty years. Its advanced networking, security, and storage features have made FreeBSD the platform of choice for many of the busiest web sites and most pervasive embedded networking and storage devices.
For copyright information, please see the file COPYRIGHT in this directory. Additional copyright information also exists for some sources in this tree - please see the specific source directories for more information.
The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree. See build(7), config(8), FreeBSD handbook on building userland, and Handbook for kernels for more information, including setting make(1) variables.
For information on the CPU architectures and platforms supported by FreeBSD, see the FreeBSD website's Platforms page.
Source Roadmap:
Directory | Description |
---|---|
bin | System/user commands. |
cddl | Various commands and libraries under the Common Development and Distribution License. |
contrib | Packages contributed by 3rd parties. |
crypto | Cryptography stuff (see crypto/README). |
etc | Template files for /etc. |
gnu | Commands and libraries under the GNU General Public License (GPL) or Lesser General Public License (LGPL). Please see gnu/COPYING and gnu/COPYING.LIB for more information. |
include | System include files. |
kerberos5 | Kerberos5 (Heimdal) package. |
lib | System libraries. |
libexec | System daemons. |
release | Release building Makefile & associated tools. |
rescue | Build system for statically linked /rescue utilities. |
sbin | System commands. |
secure | Cryptographic libraries and commands. |
share | Shared resources. |
stand | Boot loader sources. |
sys | Kernel sources (see sys/README.md). |
targets | Support for experimental DIRDEPS_BUILD |
tests | Regression tests which can be run by Kyua. See tests/README for additional information. |
tools | Utilities for regression testing and miscellaneous tasks. |
usr.bin | User commands. |
usr.sbin | System administration commands. |
For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see FreeBSD Handbook.