From: David Huggins-Daines <dhd@linuxcare.com>
To: John Marvin <jsm@udlkern.fc.hp.com>
Cc: parisc-linux@thepuffingroup.com
Subject: Re: [parisc-linux] 32 bit compiler bug causing kernel crashes
Date: 15 Sep 2000 13:43:10 -0400 [thread overview]
Message-ID: <877l8dlff5.fsf@linuxcare.com> (raw)
In-Reply-To: John Marvin's message of "Fri, 15 Sep 2000 06:06:45 -0600 (MDT)"
John Marvin <jsm@udlkern.fc.hp.com> writes:
> I've been investigating a problem that was leading to the kernel executing
> a break 0,0 (executing 0) at random times. I've tracked the problem down
> to a compiler bug.
Cool. Strangely enough I don't see this in 2.3.99pre8, only in 2.4.
The problem with userspace executing zero at random times is obviously
something else.
> So here is the code at the beginning of schedule():
>
> c0114404 <schedule>:
> c0114404: 08 03 02 41 copy r3,r1
> c0114408: 08 1e 02 43 copy sp,r3
Hm. This bit above puzzles me, because I thought the kernel was
either compiled with -fomit-frame-pointer, or with sufficient
optimization that the frame pointer would be omitted anyway.
> 4---> c011440c: 0c 68 12 90 stw r8,8(sr0,r3)
> c0114410: 08 1e 02 48 copy sp,r8
> c0114414: 6b c2 3f d9 stw rp,-14(sr0,sp)
> c0114418: 08 08 02 53 copy r8,r19
> 5---> c011441c: 6f c1 01 00 stw,ma r1,80(sr0,sp)
Wow. That is some unbelievably screwed up register spilling. In fact
I suspect that this may be a reload bug.
--
dhd@linuxcare.com, http://www.linuxcare.com/
Linuxcare. Support for the revolution.
next prev parent reply other threads:[~2000-09-15 17:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2000-09-15 12:06 [parisc-linux] 32 bit compiler bug causing kernel crashes John Marvin
2000-09-15 17:43 ` David Huggins-Daines [this message]
2000-09-27 21:45 ` David Huggins-Daines
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