From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757660Ab0J1AMv (ORCPT ); Wed, 27 Oct 2010 20:12:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:4706 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752745Ab0J1AMu (ORCPT ); Wed, 27 Oct 2010 20:12:50 -0400 Message-ID: <4CC8BFDD.8080600@redhat.com> Date: Thu, 28 Oct 2010 02:12:13 +0200 From: Michael Stefaniuc User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc13 Thunderbird/3.1.4 MIME-Version: 1.0 To: Frederic Weisbecker CC: LKML , "Rafael J. Wysocki" , Maciej Rutecki , Alexandre Julliard Subject: Regression in 2.6.36 in single stepping over hardware breakpoint (Wine) Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Frederic, there is a regression between 2.6.35 and 2.6.36 for 32bit Wine in the Wine test checking the single stepping over hardware breakpoints: /home/michi/work/wine/tools/runtest -q -P wine -M ntdll.dll -T ../../.. -p ntdll_test.exe.so /home/michi/work/wine/dlls/ntdll/tests/exception.c && touch exception.ok exception.c:585: Test failed: eip is wrong: 340002 instead of 340001 exception.c:587: Test failed: B0 flag is not set in Dr6 exception.c:588: Test failed: BS flag is set in Dr6 exception.c:593: Test failed: eip is wrong: 7ed569d3 instead of 340002 make: *** [exception.ok] Error 4 All those tests are in bpx_handler() http://source.winehq.org/git/wine.git/?a=blob;f=dlls/ntdll/tests/exception.c;h=701b6bba091dddce724075dc41dd2ab407f28ac4;hb=HEAD#l559 A regression test gives: 0c4519e825c9e2b6a8310deff8582f8c35bfbba9 is the first bad commit commit 0c4519e825c9e2b6a8310deff8582f8c35bfbba9 Author: Frederic Weisbecker Date: Thu Jun 24 21:21:27 2010 +0200 x86: Set resume bit before returning from breakpoint exception Instruction breakpoints trigger before the instruction executes, and returning back from the breakpoint handler brings us again to the instruction that breakpointed. This naturally bring to a breakpoint recursion. To solve this, x86 has the Resume Bit trick. When the cpu flags have the RF flag set, the next instruction won't trigger any instruction breakpoint, and once this instruction is executed, RF is cleared back. This let's us jump back to the instruction that triggered the breakpoint without recursion. Use this when an instruction breakpoint triggers. Signed-off-by: Frederic Weisbecker Cc: Will Deacon Cc: Prasad Cc: Mahesh Salgaonkar Cc: Paul Mackerras Cc: Ingo Molnar Cc: Jason Wessel :040000 040000 2eae1fa5f90b141d60fe28a971a618e9c0b1a232 e27fd94a1beb10e3688d555bd74c888b6a310293 M arch Reverting this patch on top of 2.6.36 makes the problem go away. The problem is 100% reproducible and I see it in 32bit Wine on both 32bit and 64bit Linux. The regression might affect also 64bit Wine but those exception tests aren't compiled for 64bit Wine due to the lack of compiler support for win64 exceptions; so we cannot test it. Steps to reproduce: ------------------- Any Wine version wine-1.2 or newer will do (either a tarball from http://sourceforge.net/projects/wine/files/Source/ or from git git clone git://source.winehq.org/git/wine.git ./configure make cd dlls/ntdll/tests/ make exception.ok Test results: The above errors on lines 585, 587, 588, 593 should not show up. Additionally there should be no error in line 665 as that means the tests didn't run (there was a temporary regression in the 2.6.36-rc phase that produced the test failed on line 665; the patch from commit 89e45aac42d4 was needed at each bisection point). For 32bit Wine builds on a x86_64 machine a pretty complete 32bit setup is needed too, but configure will let one know. If configure doesn't errors out but produces warnings, those can be safely ignored. It means the dependencies are optional and those aren't needed to reproduce this bug. http://wiki.winehq.org/WineOn64bit has a lot more info on setting this up. bye michael