Bug 198663

Description Enji Cooper 2015-03-17 17:21:15 UTC

This panic issue is 100% reproducible with the Jenkins kyua test runs; see
https://jenkins.freebsd.org/job/FreeBSD_HEAD-tests2/853/ for more details:

lib/libc/sys/chroot_test:chroot_err  ->  passed  [0.015s]
lib/libc/sys/chroot_test:chroot_perm  ->  passed  [0.015s]
lib/libc/sys/clock_gettime_test:clock_gettime_real  ->  panic: wrote past end of sbuf (0 >= 0)
cpuid = 0
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe009748b760
vpanic() at vpanic+0x189/frame 0xfffffe009748b7e0
kassert_panic() at kassert_panic+0x132/frame 0xfffffe009748b850
sbuf_set_drain() at sbuf_set_drain+0x28/frame 0xfffffe009748b880
sbuf_new_for_sysctl() at sbuf_new_for_sysctl+0x29/frame 0xfffffe009748b8a0
sysctl_kern_timecounter_choice() at sysctl_kern_timecounter_choice+0x18/frame 0xfffffe009748b900
sysctl_root_handler_locked() at sysctl_root_handler_locked+0x94/frame 0xfffffe009748b940
sysctl_root() at sysctl_root+0x188/frame 0xfffffe009748b990
userland_sysctl() at userland_sysctl+0x192/frame 0xfffffe009748ba30
sys___sysctl() at sys___sysctl+0x74/frame 0xfffffe009748bae0
amd64_syscall() at amd64_syscall+0x27f/frame 0xfffffe009748bbf0
Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfffffe009748bbf0
--- syscall (202, FreeBSD ELF64, sys___sysctl), rip = 0x800b77b0a, rsp = 0x7fffffffa938, rbp = 0x7fffffffa970 ---
KDB: enter: panic
[ thread pid 4557 tid 100062 ]

Repro:

sudo pkg install -y kyua perl5
(cd /usr/tests/; sudo kyua test)

It might be easier to repro by limiting the tests executed to just the libc syscall tests:

sudo pkg install -y kyua perl5
(cd /usr/tests/lib/libc/sys; sudo kyua test)