From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NruYo-0001VM-PJ for qemu-devel@nongnu.org; Wed, 17 Mar 2010 10:49:26 -0400 Received: from [199.232.76.173] (port=35737 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NruYo-0001VA-8c for qemu-devel@nongnu.org; Wed, 17 Mar 2010 10:49:26 -0400 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1NruYn-00065K-K9 for qemu-devel@nongnu.org; Wed, 17 Mar 2010 10:49:26 -0400 Received: from are.twiddle.net ([75.149.56.221]:56042) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NruYn-00065E-9m for qemu-devel@nongnu.org; Wed, 17 Mar 2010 10:49:25 -0400 Message-ID: <4BA0EBF3.60308@twiddle.net> Date: Wed, 17 Mar 2010 07:49:23 -0700 From: Richard Henderson MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH 4/4] tcg-hppa: Compute is_write in cpu_signal_handler. References: <14f1f6f787a15f6d6a5c3ce7f49a2e682aa339e7.1268754659.git.rth@twiddle.net> <20100317021043.GD23195@zubnet.me.uk> <20100317022357.GA23511@zubnet.me.uk> In-Reply-To: <20100317022357.GA23511@zubnet.me.uk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stuart Brady Cc: qemu-devel@nongnu.org On 03/16/2010 07:23 PM, Stuart Brady wrote: > On Wed, Mar 17, 2010 at 02:10:43AM +0000, Stuart Brady wrote: >> Argh. It just seems mind bogglingly silly that is_write doesn't seem to >> be included in the siginfo on archs where doing so would make sense... > >> It's at least something I'd have hoped libc could take care of in the case >> where the hardware doesn't indicate whether the fault was due to a read >> or a write... > > Oh, actually, I guess you'd just test the equivalent of > '(info->si_isr >> 33) & 1' or 'DSISR_sig(uc) & 0x00800000)' on such > an arch, but it still seems a shame that this isn't done for us on > archs without that ability... Unfortunately there's no reserved space in the hppa sigcontext, which is what would need to be expanded in order to store the additional info from the kernel. So in addition to a kernel patch, userland would need to change its abi. All kinda nasty, that. r~