Re: 2.2.12: kmalloc: Size (4294959124) too large

Miquel van Smoorenburg (miquels@cistron.nl)
Fri, 27 Aug 1999 15:53:22 +0200


According to Alan Cox:
> > eth0: Setting full-duplex based on MII #3 link partner capability of 41e1.
> > Starting system log daemon: syslogd klogd.
> > kmalloc: Size (4294959124) too large
>
> Something tried to allocate negative bytes.

Yep, but what ? Is there a way to let kmalloc print a stack trace
when this happens? *(int*)0=0; should cause an oops, right ?

Okay I've added that to kmalloc() in mm/slab.c. Rebooting now (if
Cistron customers read this, sorry I interrupted your news reading ...)

Duh, I'm booting the same kernel, but now with only that tiny change
to mm/slab.c, there is no kmalloc failure, and I have network connectivity.
Weird.

> > .. and I do not have network connectivity with this kernel. It looks
> > like the epic100 driver is busted. It's a module, unloading and reloading
> > gets it to work again ..
>
> The epic100 driver hasnt changed between 2.2.10->2.2.12 and probably for
> longer back than this. What kernel did you used to run ?

Well it used to run 2.0.37-pre5 ;)

I have another machine, a newsserver as well which I upgraded from
2.0.37 -> 2.2.9 -> 2.2.12-pre8. When I got to 2.2.12-pre8, the epic100
stopped working as well until I unloaded and reloaded the module. It
didn't give the kmalloc message though.

The reason I didn't report it was that a lot of other things broke as
well due to the RAID change which was in some 2.2.12-pre versions, and
I manually unloaded and loaded several modules a few times, so I
forgot about it...

Ofcourse this all doesn't make any sense since there only has been
1 minor change to the epic100 driver in patch-2.2.8.

Anyway would the *(int*)0=0; in mm/slab.c be a useful addition to
standard kernels? I've seen the same message on 2.3.13 or so on
my home machine (probably caused by ISDN) and it would be nice to
have a trace of it.

Mike.

-- 
... somehow I have a feeling the hurting hasn't even begun yet
	-- Bill, "The Terrible Thunderlizards"

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