From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22157 invoked by alias); 7 Dec 2008 22:38:29 -0000 Received: (qmail 22147 invoked by uid 22791); 7 Dec 2008 22:38:28 -0000 X-Spam-Check-By: sourceware.org Received: from mx2.redhat.com (HELO mx2.redhat.com) (66.187.237.31) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sun, 07 Dec 2008 22:37:29 +0000 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id mB7MbOVa006046; Sun, 7 Dec 2008 17:37:24 -0500 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx2.corp.redhat.com (8.13.1/8.13.1) with ESMTP id mB7MbNdF013534; Sun, 7 Dec 2008 17:37:24 -0500 Received: from host0.dyn.jankratochvil.net (sebastian-int.corp.redhat.com [172.16.52.221]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id mB7MbKw2001415; Sun, 7 Dec 2008 17:37:21 -0500 Received: from host0.dyn.jankratochvil.net (localhost [127.0.0.1]) by host0.dyn.jankratochvil.net (8.14.3/8.14.2) with ESMTP id mB7MbI5t014502; Sun, 7 Dec 2008 23:37:19 +0100 Received: (from jkratoch@localhost) by host0.dyn.jankratochvil.net (8.14.3/8.14.2/Submit) id mB7MbHDC014499; Sun, 7 Dec 2008 23:37:17 +0100 Date: Sun, 07 Dec 2008 22:38:00 -0000 From: Jan Kratochvil To: gdb-patches@sourceware.org Cc: Ulrich Weigand , Daniel Jacobowitz Subject: [patch] Fix hw watchpoints regression on i386/x86_64/ia64 Message-ID: <20081207223717.GA13952@host0.dyn.jankratochvil.net> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="y0ulUmNC+osPPQO6" Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2008-12/txt/msg00143.txt.bz2 --y0ulUmNC+osPPQO6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-length: 1234 Hi, there is now a regression for watchpoints created before the inferior is started. With no active target the only target in the stack is `exec' which has no `to_can_use_hw_breakpoint' in its vector. Therefore only a software watchpoint gets created. Later the watchpoint type remains the same (software one). I find incorrect to determine the watchpoint type (sw/hw) the time it gets created when no target is active. GDB cannot know the hw watchpoints support availability that time. In some ideal case bp_watchpoint vs. bp_hardware_watchpoint should be completely hidden from the user. But as the watchpoint type is not absolutely transparent I chose a more conservative way to just convert bp_watchpoint<->bp_hardware_watchpoint appropriately when the relevant runtime conditions may change. The regression for ia64 got introduced starting with 6.7: http://sourceware.org/ml/gdb-patches/2007-03/msg00290.html http://sourceware.org/ml/gdb-cvs/2007-03/msg00114.html The regression for i386/x86_64 got introduced only in post-6.8 CVS HEAD: http://sourceware.org/ml/gdb-patches/2008-03/msg00000.html http://sourceware.org/ml/gdb-cvs/2008-03/msg00002.html No regressions on {x86_64,ia64}-unknown-linux-gnu. Regards, Jan --y0ulUmNC+osPPQO6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="gdb-watchpoint-hw.patch" Content-length: 4875 2008-12-07 Jan Kratochvil Fix hw watchpoints created before the inferior was started. * breakpoint.c (update_watchpoint): Convert the bp_watchpoint and bp_hardware_watchpoint types according to the current runtime state. (insert_breakpoints): Call update_watchpoint even for `bp_watchpoint's. 2008-12-07 Jan Kratochvil * gdb.base/watchpoint-hw.exp, gdb.base/watchpoint-hw.c: New. --- gdb/breakpoint.c 7 Dec 2008 15:59:51 -0000 1.364 +++ gdb/breakpoint.c 7 Dec 2008 21:20:54 -0000 @@ -892,6 +892,28 @@ update_watchpoint (struct breakpoint *b, b->val_valid = 1; } + /* Change the type of breakpoint between hardware assisted or an + ordinary watchpoint depending on the hardware support and free + hardware slots. */ + if (b->type == bp_watchpoint || b->type == bp_hardware_watchpoint) + { + int i, mem_cnt, target_resources_ok, other_type_used; + + i = hw_watchpoint_used_count (bp_hardware_watchpoint, + &other_type_used); + mem_cnt = can_use_hardware_watchpoint (val_chain); + + /* Hack around 'unused var' error for some targets here. */ + (void) i; + if (mem_cnt) + target_resources_ok = TARGET_CAN_USE_HARDWARE_WATCHPOINT + (bp_hardware_watchpoint, i + mem_cnt, other_type_used); + if (!mem_cnt || target_resources_ok <= 0) + b->type = bp_watchpoint; + else + b->type = bp_hardware_watchpoint; + } + /* Look at each value on the value chain. */ for (v = val_chain; v; v = next) { @@ -1204,8 +1226,9 @@ insert_breakpoints (void) { struct breakpoint *bpt; + /* Software watchpoint may get converted to hardware ones. */ ALL_BREAKPOINTS (bpt) - if (is_hardware_watchpoint (bpt)) + if (is_hardware_watchpoint (bpt) || bpt->type == bp_watchpoint) update_watchpoint (bpt, 0 /* don't reparse. */); update_global_location_list (1); --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ gdb/testsuite/gdb.base/watchpoint-hw.c 7 Dec 2008 21:20:56 -0000 @@ -0,0 +1,27 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2008 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . + + Please email any bugs, comments, and/or additions to this file to: + bug-gdb@prep.ai.mit.edu */ + +int watchee; + +int +main (void) +{ + return 0; +} --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ gdb/testsuite/gdb.base/watchpoint-hw.exp 7 Dec 2008 21:20:56 -0000 @@ -0,0 +1,50 @@ +# Copyright 2008 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +if {![istarget "i?86-*-*"] && ![istarget "x86_64-*-*"] && ![istarget "ia64-*-*"] + && ![istarget "s390*-*-*"]} then { + verbose "Skipping watchpoint-hw test." + return +} + +set testfile watchpoint-hw +set srcfile ${testfile}.c +set binfile ${objdir}/${subdir}/${testfile} +if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } { + untested "Couldn't compile test program" + return -1 +} + +gdb_exit +gdb_start +gdb_reinitialize_dir $srcdir/$subdir +gdb_load ${binfile} + +# Create the watchpoint before the inferior gets started. Now the native CPU +# target is still not active and its `to_can_use_hw_breakpoint' is not +# installed, therefore only a software watchpoint gets created. + +gdb_test "watch watchee" "atchpoint 1: watchee" + +# `runto_main' or `runto main' would delete the watchpoint created above. + +if { [gdb_start_cmd] < 0 } { + untested start + return -1 +} +gdb_test "" "main .* at .*" "start" + +# Check it is really a `hw'-watchpoint. +gdb_test "info watchpoints" "1 *hw watchpoint .* watchee" --y0ulUmNC+osPPQO6--