From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:46682) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Q9caF-0002Jd-Al for qemu-devel@nongnu.org; Tue, 12 Apr 2011 08:20:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Q9caD-0000En-G2 for qemu-devel@nongnu.org; Tue, 12 Apr 2011 08:20:39 -0400 Received: from adelie.canonical.com ([91.189.90.139]:33255) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Q9caD-0000De-67 for qemu-devel@nongnu.org; Tue, 12 Apr 2011 08:20:37 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by adelie.canonical.com with esmtp (Exim 4.71 #1 (Debian)) id 1Q9caB-0005u7-W7 for ; Tue, 12 Apr 2011 12:20:36 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id F1F8C2E8059 for ; Tue, 12 Apr 2011 12:20:35 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Tue, 12 Apr 2011 12:10:43 -0000 From: Anup Patel <757702@bugs.launchpad.net> Sender: bounces@canonical.com References: <20110411161233.16764.21820.malonedeb@soybean.canonical.com> <20110412114242.24274.9945.malone@wampee.canonical.com> Message-Id: Errors-To: bounces@canonical.com Subject: Re: [Qemu-devel] [Bug 757702] Re: Undefined instruction exception starts at offset 0x8 instead of 0x4 Reply-To: Bug 757702 <757702@bugs.launchpad.net> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org I see 0x00000008 (). I am using qemu-0.14.0.tar.gz available for QEMU Downloads. --Anup On Tue, Apr 12, 2011 at 5:12 PM, Peter Maydell wrote: > > Also, in the test case hits 0x8 after encountering UNDEF instruction > at 0x100058. > > So if you run qemu like this: > qemu-system-arm -M realview-pb-a8 -serial stdio -kernel arm_test.elf -s -S > > and run arm-none-gnueabi-gdb with no arguments and in gdb type these > commands: > > (gdb) target remote :1234 > Remote debugging using :1234 > 0x00100000 in ?? () > (gdb) break *0x4 > Breakpoint 1 at 0x4 > (gdb) break *0x8 > Breakpoint 2 at 0x8 > (gdb) c > Continuing. > > ...what does gdb do? > (For me it says "Breakpoint 1, 0x00000004 in ?? ()" which is what I > expect.) > > -- > You received this bug notification because you are a direct subscriber > of the bug. > https://bugs.launchpad.net/bugs/757702 > > Title: > Undefined instruction exception starts at offset 0x8 instead of 0x4 > > Status in QEMU: > New > > Bug description: > ARMv7a has lot of undefined instruction from its instruction opcode > space. This undefined instructions are very useful for replacing > sensitive non-priviledged instructions of guest operating systems > (virtualization). The undefined instruction exception executes at > + 0x4, where can be 0x0 or > 0xfff00000. Currently, in qemu 0.14.0 undefined instruction fault at > 0x8 offset instead of 0x4. This was not a problem with qemu 0.13.0, > seems like this is a new bug. As as example, if we try to execute > value "0xec019800" in qemu 0.14.0 then it should cause undefined > exception at +0x4 since "0xec019800" is an undefined > instruction. > > To unsubscribe from this bug, go to: > https://bugs.launchpad.net/qemu/+bug/757702/+subscribe > -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/757702 Title: Undefined instruction exception starts at offset 0x8 instead of 0x4 Status in QEMU: New Bug description: ARMv7a has lot of undefined instruction from its instruction opcode space. This undefined instructions are very useful for replacing sensitive non-priviledged instructions of guest operating systems (virtualization). The undefined instruction exception executes at + 0x4, where can be 0x0 or 0xfff00000. Currently, in qemu 0.14.0 undefined instruction fault at 0x8 offset instead of 0x4. This was not a problem with qemu 0.13.0, seems like this is a new bug. As as example, if we try to execute value "0xec019800" in qemu 0.14.0 then it should cause undefined exception at +0x4 since "0xec019800" is an undefined instruction.