Date: Wed, 13 Jan 1999 10:58:56 -0500 (EST) From: Andrew Gallatin <gallatin@cs.duke.edu> To: Hidetoshi Shimokawa <simokawa@sat.t.u-tokyo.ac.jp> Cc: alpha@FreeBSD.ORG Subject: Re: fatal kernel trap Message-ID: <13980.47994.716203.197346@grasshopper.cs.duke.edu> In-Reply-To: <19990113095116Q.simokawa@sat.t.u-tokyo.ac.jp> References: <19990113095116Q.simokawa@sat.t.u-tokyo.ac.jp>
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Hidetoshi Shimokawa writes: > fatal kernel trap: > > trap entry = 0x3 (instruction fault) > a0 = 0x4 > a1 = 0xfffffe000e05a000 > a2 = 0xfffffe0000f70910 > pc = 0x12011019c > ra = 0x120110180 > curproc = 0xfffffe000df75600 > pid = 46114, comm = gtags I don't really pretend to understand this, but according to The Alpha AXP Architecture reference manual (2nd edition), a0 means you got an 'opDec' According to page II-B, 1-5, an opdec is an 'attempt .. to execute a reserved instruction or a privleged instruction in user mode' According to (II-B pg 5-6), the saved PC is the address of the instruction after the instruction that caused the fault. I don't really understand how this could have happened given that a) the pc/ra are in usermode b) the palcode must have thought the machine was in usermode to deliver an opdec (at least the AXP ref man. gives me that impression) c) the trap handler thinks the machine is in kernel mode, otherwise you wouldn't have gotten a panic What instruction is at that address in gtags? Hmm.. Just a guess, but maybe it has something to do with taking a trap in the new fp emulation code.. Drew ------------------------------------------------------------------------------ Andrew Gallatin, Sr Systems Programmer http://www.cs.duke.edu/~gallatin Duke University Email: gallatin@cs.duke.edu Department of Computer Science Phone: (919) 660-6590 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message
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