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Re: netbsd-5: panic: ureadc: non-positive resid

        Hello.  If you're using a stock 5.0 kernel, then you might be running
into kern/41566, which I believe has been fixed in the 5.x branch as  of
mid July 2009.
On Oct 11,  1:18am, Matthew Mondor wrote:
} Subject: netbsd-5: panic: ureadc: non-positive resid
} Under some circumstances, the following panic occurs:
} panic: ureadc: non-positive resid
} Interestingly, I've been able to reproduce it in the following peculiar
} way.
} Using a program such as:
} #include <sys/types.h>
} #include <sys/uio.h>
} #include <unistd.h>
} int main(void)
} {
}       struct iovec iov[1];
}       char buffer[1024];
}       iov[0].iov_base = buffer;
}       iov[0].iov_len = 0;
}       return preadv(0, iov, 1, 0);
} }
} which of course, normally fails with EINVAL.  Using readv(2) there also
} has the same issue in this particular case.  I paniced this box often
} enough for tonight but don't exactly remember if this also happens with
} read(2) and length zero.
} I can run the above test on the text console alone as much as I want
} without issue, yet if I start screen(1) and then run such a command, it
} allows to read from stdin and waits there until I press enter, at
} which point the panic occurs.
} I yet have to build a debug kernel and test this, as well as to run a
} RAM check on this system, but wondered if perhaps someone had a clue
} about an actual reason this could occur (i.e. a bug in the pty code or
} whatever).
} Thanks,
} -- 
} Matt
>-- End of excerpt from Matthew Mondor

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