Messages in this thread | | | From | "James Washer" <> | Date | Wed, 20 Mar 2002 15:46:49 -0800 | Subject | Re: Bad Illegal instruction traps on dual-Xeon (p4) Linux Dell box |
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Just to clarify things.
Lots of processes die from illegal op traps.. gcc, bash, make, etc... but the instruction is ALWAYS opcode 0x55 and is part of a subroutine preamble in every case.. You are correct... 0x55 should not generate a trap.
Bad cpu? Hmmm, Tom has 6 different CPU's ( all p4 xeons ), on three systems, that have this EXACT same problem.
and why does this require the system to be running smp?
- jim
Kurt Garloff <kurt@garloff.de>@vger.kernel.org on 03/20/2002 03:26:10 PM
Sent by: linux-kernel-owner@vger.kernel.org
To: Tom Epperly <tepperly@llnl.gov> cc: Linux kernel list <linux-kernel@vger.kernel.org> Subject: Re: Bad Illegal instruction traps on dual-Xeon (p4) Linux Dell box
On Wed, Mar 20, 2002 at 01:35:30PM -0800, Tom Epperly wrote: > The kernel log showed me that various standard programs such as > /bin/sh are generating bogus illegal instruction traps on a legal > opcode (0x55) as part of a standard function preamble. After receiving > an illegal instruction trap on opcode (0x55), the modified kernel does > a wbinvd() to flush the cache and a __flush_tlb() to flush the TLB > and then retries the "illegal" opcode. The retry produces a second > illegal instruction trap on the same legal opcode (0x55). Information > from /var/log/messages is shown below.
The CPU is what triggers the exception. So this sounds like a defect (or overheated) CPU to me.
OTOH, the kernel logs "invalid operand". Could you run ksymoops to get a disassembly? AFAICS, its a push %ebp instruction, which should not be illegal. So either your stack is overflowing or my suspicion with the defect CPU is applicable.
Regards, -- Kurt Garloff <kurt@garloff.de> [Eindhoven, NL] Physics: Plasma simulations <K.Garloff@Phys.TUE.NL> [TU Eindhoven, NL] Linux: SCSI, Security <garloff@suse.de> [SuSE Nuernberg, DE] (See mail header or public key servers for PGP2 and GPG public keys.)
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