Date: Tue, 15 Jan 2013 18:55:11 -0800 From: Garrett Cooper <yanegomi@gmail.com> To: Jilles Tjoelker <jilles@stack.nl> Cc: FreeBSD Current <freebsd-current@freebsd.org>, kib@freebsd.org Subject: Re: ktrace -d broken on current/stable-9 Message-ID: <CAGH67wTwfp=VTu4YGKWYtyT1fks9F6gWJjA_FB-arK=M%2BZWa0w@mail.gmail.com> In-Reply-To: <20130115225305.GA12294@stack.nl> References: <4850A09B-A054-4B38-891C-06673F7195B2@gmail.com> <20130115225305.GA12294@stack.nl>
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On Tue, Jan 15, 2013 at 2:53 PM, Jilles Tjoelker <jilles@stack.nl> wrote:
> On Mon, Jan 14, 2013 at 06:48:13PM -0800, Garrett Cooper wrote:
>> I tried using ktrace on a kernel compiled a week ago, and it appears
>> to not be following forks like it should on amd64:
>
>> # ktrace -d ./regress -l
>> [snip]
>
>> Not sure how it broke, but it was working a couple months ago (in
>> particular I remember it working either around October or November),
>> and the bug seems to have worked its way back to 9-STABLE (I'm running
>> into the same problem if I do ktrace -d, enter a shell, then exec
>> another shell from that shell). Haven't spent the time to bisect the
>> commits looking for the culprit (yet), but if need be I'll trace down
>> the culprit sometime this week.
>
>> truss works, so it doesn't seem like ptrace(2) is broken.
>
> ktrace -d is not really useful in the synopsis with a command. It only
> means that the child processes of ktrace (at a time just before it
> executes the utility) should be traced as well. This is almost always an
> empty set, unless you do things like
> cmd1 & ktrace -d cmd2
> which will trace cmd2 and part of cmd1.
>
> You probably want ktrace -i.
Dangit -- forgot about that option. Ok, PEBKAC award for me.
Thanks,
-Garrett
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