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Re: Sudden “operation not permitted”




On 4/17/19 1:19 PM, Marc Auslander wrote:
David Christensen <dpchrist@xxxxxxxxxxxxxxxx> writes:

On 4/16/19 11:25 PM, Mark Fletcher wrote:
(Apologies if this mail comes through poorly formatted for the list; my
main machine is unavailable due to this problem and I’m writing on an
iPad...)

Running Stretch on a circa-2009 self-built machine which has run happily
without serious issues since it was built, apart from the odd annoyance
with Bluetooth audio which the list has already had the pleasure of hearing
about.

This morning I unlocked it before leaving home, and noticed that load was
fairly constant at about 1.0 when it should have been at 0 as the machine
should have been idle. I listed processes with top and noticed that upowerd
was taking up a whole CPU to itself. Normally I wouldn’t notice this daemon
doing its thing.

Google turned up nothing relevant.

I decided to try a reboot, which cleared the upowerd problem and returned
load to 0 or close to it. But now, network activity is not working. Any
attempt to ping an IP address (eg my router) results in “Operation not
permitted” even when run as root. Attempt to access any web page results in
failing to find the site. Attempting to ping a text domain (eg
www.google.com) results in an error message (instantly) saying could not
resolve...

It seems like networking is bejiggered suddenly on this machine. I did not
install updates before rebooting, last time updates were installed was
Sunday, and all has been well since then until this morning, although I did
not reboot during that period until this morning. The machine is attached
to my network via an Ethernet cable running to a WiFi+wired router. That is
obviously working as the machine was able to get an IP address by DHCP
after the reboot (ip route after reboot showed IP address correctly
assigned) but unable to resolve any address and unable to ping an IP
address of the form 192.168.xx.yy with the “Operation not permitted” error.

All the pinging I’ve been trying worked without issues before this problem
occurred, both as root and as an unprivileged user.

Looking through the journalctl since my reboot, I do not see anything that
obviously points to the problem. Network Manager seems to start OK, as far
as I can tell. I don’t see any significant errors except postgreSQL failing
to start, which is normal and I don’t use it. The first sign of trouble (to
my eye, anyway) in the boot log is when services that want the network eg
ntp start trying to interact with it, and failing.

A second reboot produced exactly the same result. Other devices on my
network are working fine.

Putting the upowerd behavior together with the suddenness of this problem,
I’m very afraid that this isn’t really permissions and is in fact some sort
of hardware issue — the machine is 10 years old, was built by me, and has
been in continuous use since it was built... Any suggestions for what I can
do to diagnose?

Thanks in advance

Mark

If you updated/ upgraded but did not reboot, then there could be a
problem with one or more upgrades.  (I try to reboot immediately after
upgrading to avoid delayed surprises.)


I would pull the system drive, put it into a second machine, boot it,
and see if the problems persist.  I would also run the system drive
manufacturer's diagnostic tool and test the system drive.


While testing the system drive in another machine, I would test the
first machine -- e.g. verify all cables fully seated, test the power
supply with a hardware tester, run any motherboard firmware
diagnostics, run software memory diagnostics, etc..


David

Wouldn't it make more sense to boot a rescue CD and see if the hardware
works - specifically the networking?

Using a rescue CD, live CD, another system drive (USB or SATA), etc., would all be additional options for "test the first machine".


David