From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Mosberger Date: Fri, 30 May 2003 16:32:03 +0000 Subject: Re: [Linux-ia64] sigaltstack and ar.bspstore 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 Sat, 31 May 2003 00:18:39 +1000, Matt Chapman said: Matt> Presumably the result should be the same as the original Matt> bspstore. However, it isn't in the case when the original Matt> bspstore is pointing to slot 63 (the RNAT word). The new Matt> bspstore comes out pointing to slot 0 of the next group, and Matt> the RNAT bits never get written. This happens more often then Matt> you'd expect, since it seems that current implementations make Matt> the optimisation of writing the RNAT word together with the Matt> first word of the new group instead of the last word of the Matt> old group (sensible because it potentially saves a write). Yes, I noticed the same in libunwind. ;-/ Matt> I'd propose that the trampoline code should save bspstore in Matt> the sigcontext structure and restore it from there rather than Matt> recalculating it. I can send a patch, but first is there any Matt> reason why it shouldn't be done that way? My preference would be to fix it in a way that preserves binary compatibility for the sigcontext structure. --david