DTrace script asserts and kills the other process

[ambrosehuang ambrose]

2011/8/3 Andriy Gapon <avg at freebsd.org>

> on 28/07/2011 07:10 ambrosehuang ambrose said the following:
> >> Yuri <yuri at rawbw.com> wrote:
> >>
> >>> I am trying to run this dtrace script:
> >>>
> >>> #!/usr/sbin/dtrace -s
> >>> pid123:libc::entry
> >>> {
> >>> self->timestmp[probefunc] = timestmp;
> >>> }
> >>> pid123:libc::return
> >>> /self->timestmp[probefunc] != 0/
> >>> {
> >>> @function_duration[probefunc] = sum(timestmp -
> >>> self->timestmp[probefunc]); timestmp[probefunc] = 0;
> >>> }
> >>>
> >>> which I got from here:
> >>> http://www.princeton.edu/~unix/Solaris/troubleshoot/dtrace.html
> >>> replacing 123 with the pid of some running process.
> >>>
> >>> Result: dtrace utility asserts:
> >>> Assertion failed: (dpr != NULL), file
> >>>
> >>
> /usr/src/cddl/lib/libdtrace/../../../cddl/contrib/opensolaris/lib/libdtrace/common/dt_proc.c,
> >>> line 751.
> >>> Abort trap: 6
> >>>
> >>> Also the target process is killed too:
> >>> Killed: 9
> >>>
> >>> 8.2-STABLE amd64
> >>
> >> This is a known issue. You may be able to work around it by
> >> letting dtrace start the traced process.
> >>
> >> There's already a PR about it:
> >> http://www.freebsd.org/cgi/query-pr.cgi?pr=bin/158431
> >> but the limitation isn't mentioned in the wiki:
> >> http://wiki.freebsd.org/DTrace/userland
>
> FYI and benefit:  I've committed what should be a fix for this issue,
> r224632.
>
> >> It's not clear to me if this has worked in the past or if it
> >> works for other architectures (the reporter and I are both using
> >> amd64, too).
> >>
> >> Fabian
> >>
> > I came across the same problem in 8.2-stable , it seemed the problem had
> > been there since 8.2-release with userland dtrace integrated. I followed
> the
> > PR185431 and found when  dtrace  started, it indeed attached to the
> traced
> > process( dpr != NULL), but the traced process died soon, and
> > according to the PR, this is "error in error" since the dtrace  came
> accross
> > error in dfatal
> >
> ....................................................................................................................................................
> > #3 0x0000000808d8af2d in dt_proc_lookup (dtp=0x80b841000, P=0x80d7ffb40,
> > remove=0)
> > at
> >
> /usr/src/cddl/lib/libdtrace/../../../cddl/contrib/opensolaris/lib/libdtrace/common/dt_proc.c:751
> > #4 0x0000000808d8af92 in dt_proc_destroy (dtp=0x80b841000, P=0x80d7ffb40)
> > at
> >
> /usr/src/cddl/lib/libdtrace/../../../cddl/contrib/opensolaris/lib/libdtrace/common/dt_proc.c:763
> > #5 0x0000000808d8bc6e in dt_proc_hash_destroy (dtp=0x80b841000)
> > at
> >
> /usr/src/cddl/lib/libdtrace/../../../cddl/contrib/opensolaris/lib/libdtrace/common/dt_proc.c:1162
> > #6 0x0000000808daa4b5 in dtrace_close (dtp=0x80b841000)
> > at
> >
> /usr/src/cddl/lib/libdtrace/../../../cddl/contrib/opensolaris/lib/libdtrace/common/dt_open.c:1554
> > #7 0x0000000000402775 in dfatal (fmt=0x408572 "no probes %s\n")
> > at
> >
> /usr/src/cddl/usr.sbin/dtrace/../../../cddl/contrib/opensolaris/cmd/dtrace/dtrace.c:236
> > #8 0x0000000000406b2c in main (argc=3, argv=0x7ffffffed9c0)
> > at
> >
> /usr/src/cddl/usr.sbin/dtrace/../../../cddl/contrib/opensolaris/cmd/dtrace/dtrace.c:1825
> >
> .....................................................................................................................................................
> > _______________________________________________
> > freebsd-hackers at freebsd.org mailing list
> > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers
> > To unsubscribe, send any mail to "
> freebsd-hackers-unsubscribe at freebsd.org"
> >
>
> I just saw  your  commit, I will verify it on 8-stable soon, thank you!
>
--
> Andriy Gapon
>