From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from majordomo@localhost) by oss.sgi.com (8.11.3/8.11.3) id f2JE7nH31733 for linux-mips-outgoing; Mon, 19 Mar 2001 06:07:49 -0800 Received: from mx.mips.com (mx.mips.com [206.31.31.226]) by oss.sgi.com (8.11.3/8.11.3) with ESMTP id f2JE7mM31730 for ; Mon, 19 Mar 2001 06:07:48 -0800 Received: from newman.mips.com (ns-dmz [206.31.31.225]) by mx.mips.com (8.9.3/8.9.0) with ESMTP id GAA05551 for ; Mon, 19 Mar 2001 06:07:48 -0800 (PST) Received: from copfs01.mips.com (copfs01 [192.168.205.101]) by newman.mips.com (8.9.3/8.9.0) with ESMTP id GAA00622 for ; Mon, 19 Mar 2001 06:07:46 -0800 (PST) Received: from mips.com (copsun17 [192.168.205.27]) by copfs01.mips.com (8.9.1/8.9.0) with ESMTP id PAA02100 for ; Mon, 19 Mar 2001 15:07:15 +0100 (MET) Message-ID: <3AB61293.5652407C@mips.com> Date: Mon, 19 Mar 2001 15:07:15 +0100 From: Carsten Langgaard X-Mailer: Mozilla 4.75 [en] (X11; U; SunOS 5.7 sun4u) X-Accept-Language: en MIME-Version: 1.0 To: linux-mips@oss.sgi.com Subject: Bug in the _save_fp_context. Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: 7bit Sender: owner-linux-mips@oss.sgi.com Precedence: bulk I think there is a bug in the _save_fp_context function in arch/mips/kernel/r4k_fpu.S The problem is the following piece of code: jr ra .set nomacro EX(sw t0,SC_FPC_EIR(a0)) nop .set macro First of all what should the ".set nomacro" do? If it means that the EX macro shouldn't be used then this entry wouldn't get into __ex_table, which would be wrong. But it look like it uses the macro anyway, regardless of the ".set nomacro", at least with the compiler I use. Never the less we do not handle entries in the __ex_table which is located in a branch delay. So we need to handle the situation where we take a page fault on an instruction which is located in a brach delay slot, or we don't put the "potential" faulting instruction in a delay slot. Any ideas, how we should handle this in a nice and clean way? /Carsten -- _ _ ____ ___ Carsten Langgaard Mailto:carstenl@mips.com |\ /|||___)(___ MIPS Denmark Direct: +45 4486 5527 | \/ ||| ____) Lautrupvang 4B Switch: +45 4486 5555 TECHNOLOGIES 2750 Ballerup Fax...: +45 4486 5556 Denmark http://www.mips.com