Build failed in Jenkins: FreeBSD_HEAD-tests2 #854

[Konstantin Belousov]

On Fri, Mar 20, 2015 at 03:20:26AM +0100, Mateusz Guzik wrote:
> On Fri, Mar 20, 2015 at 02:08:23AM +0000, jenkins-admin at freebsd.org wrote:
> > lib/libc/sys/setrlimit_test:setrlimit_nproc  ->  maxproc limit exceeded by uid 977 (pid 29170); see tuning(7) and login.conf(5)
> > passed  [0.551s]
> > lib/libc/sys/setrlimit_test:setrlimit_perm  ->  panic: mutex process lock not owned at /builds/FreeBSD_HEAD/sys/kern/kern_prot.c:1974
> > cpuid = 1
> > KDB: stack backtrace:
> > db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe009749a8e0
> > vpanic() at vpanic+0x189/frame 0xfffffe009749a960
> > panic() at panic+0x43/frame 0xfffffe009749a9c0
> > __mtx_assert() at __mtx_assert+0xc2/frame 0xfffffe009749a9d0
> > proc_set_cred() at proc_set_cred+0x36/frame 0xfffffe009749a9f0
> > fork1() at fork1+0x27e/frame 0xfffffe009749aac0
> > sys_fork() at sys_fork+0x1f/frame 0xfffffe009749aae0
> > amd64_syscall() at amd64_syscall+0x27f/frame 0xfffffe009749abf0
> > Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfffffe009749abf0
> > --- syscall (0, FreeBSD ELF64, nosys), rip = 0x8019c216a, rsp = 0x7fffffffc2d8, rbp = 0x7fffffffc340 ---
> > KDB: enter: panic
> > [ thread pid 660 tid 100065 ]
> > Stopped at      kdb_enter+0x3e: movq    $0,kdb_why
> 
> Weird, I'll look at that.

This is due to p_ucred not initialized on allocation of struc proc.
The member is not in p_startzero/p_endzero region, so it contains
garbage at the stage of the fork where proc_set_cred() is called,
while the function makes assertion based on the p_ucred content.