From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keith Owens Date: Mon, 09 Dec 2002 22:04:25 +0000 Subject: Re: [Linux-ia64] Unwind can load wrong data from pt_regs 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 Mon, 9 Dec 2002 13:21:07 -0800, David Mosberger wrote: >>>>>> On Mon, 09 Dec 2002 19:35:03 +1100, Keith Owens said: > > Keith> This implicitly assumes that when a fr or br register is > Keith> required from pt_regs, info->sp is pointing to pt_regs. But > Keith> info->sp is modified as the code unwinds through each > Keith> function. The above code only gives correct results for > Keith> register lookups from the failing function. Unwinding and > Keith> accessing a fr or br register from earlier functions loads > Keith> incorrect values for those registers. > >Yes, this is something that has been fixed already in the user-level >libunwind. It's not hard to fix, just someone needs to get around to >do it. I don't think it's a critical issue, since it only happens for >nested traps. I assume you saw this with kdb? How did you guess :). I will look at libunwind and do a kernel fix.