Date: Sun, 4 Mar 2001 17:10:02 -0800 (PST) From: Matthew Jacob <mjacob@feral.com> To: freebsd-alpha@freebsd.org Subject: Re: alpha/25535: unaligned access crash on stq Message-ID: <200103050110.f251A2T86680@freefall.freebsd.org>
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The following reply was made to PR alpha/25535; it has been noted by GNATS. From: Matthew Jacob <mjacob@feral.com> To: User Raymond <raymond@one.com.au> Cc: freebsd-gnats-submit@FreeBSD.ORG Subject: Re: alpha/25535: unaligned access crash on stq Date: Sun, 4 Mar 2001 17:02:21 -0800 (PST) (let's keep the audit trail in the PR) On Mon, 5 Mar 2001, User Raymond wrote: > Subj: alpha/25535: unaligned access crash on stq > To: mjacob@feral.com > From: raymond@one.com.au > > > > How is this a bug? If you try and access unaligned values you'll get > > unaligned traps. > > Sorry - I didn't explain myself at all well did I? > > The example was the only way I could force that to happen and I don't > know whether the OS is supposed to trap that and fix it on the fly. > > The original is in a much larger piece of code that ends up with a structure > unalligned and I can't work out how to get around it. I am porting the > code from the x86 platform and not having much luck. > > Any pointers would be appreciated. > > Ray Newman > Pointers indeed! :-) farrago.feral.com > uname -a FreeBSD farrago.feral.com 4.2-STABLE FreeBSD 4.2-STABLE #6: Sun Mar 4 13:33:54 PST 2001 mjacob@farrago.feral.com:/tstsys/compile/GPLUS alpha farrago.feral.com > sysctl -a|grep alig vfs.nfs.realign_test: 20065 vfs.nfs.realign_count: 0 machdep.unaligned_print: 1 machdep.unaligned_fix: 1 machdep.unaligned_sigbus: 0 If you set machdep.unaligned_fix to 0, it will stop fixups. The default is to do the fixup. If you set machdep.unaligned_print to 0, it won't print. You might consider how to get the structure aligned as it's much more than just alpha that has this issue. -matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message
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