From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jack Steiner Date: Wed, 13 Mar 2002 13:58:32 +0000 Subject: Re: [Linux-ia64] Exception handling and recovery Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org > > On Tue, 12 Mar 2002 20:51:13 -0800, > David Mosberger wrote: > >>>>>> On Wed, 13 Mar 2002 14:53:31 +1100, Keith Owens said: > > > > Keith> Unlike i386, the ia64 exception table code only recovers from > > Keith> invalid user space addresses. kdb can get other faults which > > Keith> EX() does not currently allow recovery from. Is there any > > Keith> reason why I should not add exception table handling to > > Keith> ia64_fault(), to generalize the fault recovery mechanism? > > > >You mean kdb would do get_user() on a bad pointer, which triggers > >ia64_fault() and then you want to search the exception table in > >ia64_fault()? I think it would be ok to do this (in the KDB patch). > > Exactly. IMHO ia64_fault should always search_exception_table(), even > if kdb is not installed. Other architectures use exception tables to > detect if the hardware supports extra instructions, registers, MSR > values etc., exception recovery should be general purpose. > I may have missed the context of the question, but on IA64 if kdb makes a reference to a bad region 6 or 7 pointer, it may trigger an MCA. MCAs are not recoverable via search_exception_table(). -- Thanks Jack Steiner (651-683-5302) (vnet 233-5302) steiner@sgi.com