From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 127110 invoked by alias); 6 Feb 2019 22:36:20 -0000 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 Received: (qmail 127086 invoked by uid 89); 6 Feb 2019 22:36:19 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,KAM_SHORT,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 spammy= X-HELO: userp2130.oracle.com Received: from userp2130.oracle.com (HELO userp2130.oracle.com) (156.151.31.86) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 06 Feb 2019 22:36:16 +0000 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x16MSdbk040289; Wed, 6 Feb 2019 22:36:11 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=LnmLR0daJ4WdVyyQj4APmjynHSGl+0gpk3KjF6CdxeY=; b=ple+ktbUET50qM78ocQQh2A6ZsJG3+Dgij9CqWocoUR2HDR7WIKRl2RnaQP+JJTcSQXt yBSIqGzyf+QcOQMGt0zl3vVZM6hA2tL8ONcZeV4ulqDbNlRVWo32nB/u3KKrlLKRneXG YMr/ZPAvujq2auNAK/LI65cfNPmXs4apfuN5q7L5MKlM5gZUUTmxzCauI2ElBbwsDaFF Zdy6daqq3u5u1hsweO1Bws0zPSCuVaA/ScmGlV0dsh0HNskcQfrlorCcCgRIZf256E28 GpuLeu47irUlkt8hXxAyBYOJ1cRUYZHy6szxVYm1gws/9y9wVjHSdPakCYXKIlXnY27z gw== Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by userp2130.oracle.com with ESMTP id 2qd9arkv4x-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 06 Feb 2019 22:36:11 +0000 Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id x16MaACf013677 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 6 Feb 2019 22:36:10 GMT Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x16Ma9wV005119; Wed, 6 Feb 2019 22:36:10 GMT Received: from [10.159.226.235] (/10.159.226.235) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 06 Feb 2019 14:36:09 -0800 Subject: Re: [PING][PATCH v2 PR gdb/21870] aarch64: Leftover uncleared debug registers To: Alan Hayward Cc: "gdb-patches@sourceware.org" , nd References: <1530148222-12558-1-git-send-email-weimin.pan@oracle.com> <145f2e8d-4321-00a6-650a-bf8f0a483b6f@oracle.com> <7861E9FA-0293-4C16-857A-6935579C7042@arm.com> From: Wei-min Pan Message-ID: Date: Wed, 06 Feb 2019 22:36:00 -0000 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.0 MIME-Version: 1.0 In-Reply-To: <7861E9FA-0293-4C16-857A-6935579C7042@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-SW-Source: 2019-02/txt/msg00046.txt.bz2 On 2/6/2019 4:43 AM, Alan Hayward wrote: > > >> On 6 Feb 2019, at 00:51, Weimin Pan wrote: >> >> Would you please review this aarch64-specific patch? Thanks. > > > Had a few problems applying the patch directly. > Also, the changelog entry should be in the body of the email and not > the patch. Thanks for pointing it out, noted. > But, ignoring that for now... > > I ran the test case with the current HEAD on AArch64, and it passed. > I think that your issue might have already been fixed with the following > patch: > > commit 754e31689866524049b9cfc68053ed4e1293cfac > Author: Alan Hayward > Date:   9 weeks ago > >     AArch64: Racy: Don't set empty set of hardware BPs/WPs on new thread > > > My patch is roughly doing the same thing, but in a different way. > Could you check this please? Yes, your patch does fix the problem. > > I've not yet read the test case in detail. If the bug is already fixed, > then the test might still be useful. I can push the test, which is included in the bug report, upstream. Thanks. > Alan. > > >> On 7/11/2018 5:30 PM, Wei-min Pan wrote: >>> On 6/27/2018 6:10 PM, Weimin Pan wrote: >>>> At issue here is that ptrace() does not validate either address or size >>>> when setting a hardware watchpoint/breakpoint. As a result, watchpoints >>>> were set at address 0, the initial value of aarch64_debug_reg_state in >>>> aarch64_process_info, and DR_CONTROL_LENGTH (dreg_state.dbg_regs[i].ctrl) >>>> got changed to a non-zero default value, when the PTRACE_SETREGSET request >>>> was made in aarch64_linux_set_debug_regs(), in preparation for resuming >>>> the thread. >>>> >>>> I sent out a patch upstream for review last year. Yao Qi commented that >>>> he needed to take a look at ptrace implementation to better understand >>>> why this was happening. Unfortunately he didn't get a chance to do so. >>>> >>>> This is a revised patch which calls ptrace only if any debug register >>>> has changed, either address or control containing a non-zero value, >>>> in aarch64_linux_set_debug_regs() and is similar to what x86 does - >>>> x86_linux_update_debug_registers() checks if a debug register has >>>> non-zero reference count before setting it. >>>> >>>> Tested on aarch64-linux-gnu. No regressions. >>>> --- >>>> gdb/ChangeLog | 6 + >>>> gdb/nat/aarch64-linux-hw-point.c | 7 + >>>> gdb/testsuite/ChangeLog | 20 ++- >>>> gdb/testsuite/gdb.arch/aarch64-dbreg-contents.c | 179 ++++++++++++++++++++++ >>>> gdb/testsuite/gdb.arch/aarch64-dbreg-contents.exp | 40 +++++ >>>> 5 files changed, 244 insertions(+), 8 deletions(-) >>>> create mode 100644 gdb/testsuite/gdb.arch/aarch64-dbreg-contents.c >>>> create mode 100644 gdb/testsuite/gdb.arch/aarch64-dbreg-contents.exp >>>> >>>> diff --git a/gdb/ChangeLog b/gdb/ChangeLog >>>> index 7b108bf..d5bf15f 100644 >>>> --- a/gdb/ChangeLog >>>> +++ b/gdb/ChangeLog >>>> @@ -1,3 +1,9 @@ >>>> +2018-06-27 Weimin Pan >>>> + >>>> + PR gdb/21870 >>>> + * nat/aarch64-linux-hw-point.c (aarch64_linux_set_debug_regs): >>>> + Validate debug register contents before calling ptrace. >>>> + >>>> 2018-06-18 Tom Tromey >>>> * solib-aix.c (solib_aix_get_section_offsets): Return >>>> diff --git a/gdb/nat/aarch64-linux-hw-point.c b/gdb/nat/aarch64-linux-hw-point.c >>>> index a3931ea..41ac304 100644 >>>> --- a/gdb/nat/aarch64-linux-hw-point.c >>>> +++ b/gdb/nat/aarch64-linux-hw-point.c >>>> @@ -694,11 +694,18 @@ aarch64_linux_set_debug_regs (struct aarch64_debug_reg_state *state, >>>> iov.iov_len = (offsetof (struct user_hwdebug_state, dbg_regs) >>>> + count * sizeof (regs.dbg_regs[0])); >>>> + int changed_regs = 0; >>>> for (i = 0; i < count; i++) >>>> { >>>> regs.dbg_regs[i].addr = addr[i]; >>>> regs.dbg_regs[i].ctrl = ctrl[i]; >>>> + /* Check to see if any of these debug registers contains valid data, >>>> + e.g. non-zero, before calling ptrace. See PR gdb/21870. */ >>>> + if (ctrl[i] || addr[i]) >>>> + changed_regs++; >>>> } >>>> + if (changed_regs == 0) >>>> + return; >>>> if (ptrace (PTRACE_SETREGSET, tid, >>>> watchpoint ? NT_ARM_HW_WATCH : NT_ARM_HW_BREAK, >>>> diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog >>>> index a812061..0ce2d34 100644 >>>> --- a/gdb/testsuite/ChangeLog >>>> +++ b/gdb/testsuite/ChangeLog >>>> @@ -1,4 +1,9 @@ >>>> +2018-06-27 Weimin Pan >>>> + >>>> + PR gdb/21870 >>>> + * gdb.arch/aarch64-dbreg-contents.c: New file. >>>> + * gdb.arch/aarch64-dbreg-contents.exp: New file. >>>> + >>>> 2018-06-18 Tom de Vries >>>> * gdb.ada/bp_inlined_func.exp: Allow 5 breakpoint locations. >>>> diff --git a/gdb/testsuite/gdb.arch/aarch64-dbreg-contents.c b/gdb/testsuite/gdb.arch/aarch64-dbreg-contents.c >>>> new file mode 100644 >>>> index 0000000..85d4a03 >>>> --- /dev/null >>>> +++ b/gdb/testsuite/gdb.arch/aarch64-dbreg-contents.c >>>> @@ -0,0 +1,179 @@ >>>> +/* Test case for setting a memory-write unaligned watchpoint on aarch64. >>>> + >>>> + This software is provided 'as-is', without any express or implied >>>> + warranty. In no event will the authors be held liable for any damages >>>> + arising from the use of this software. >>>> + >>>> + Permission is granted to anyone to use this software for any purpose, >>>> + including commercial applications, and to alter it and redistribute it >>>> + freely. */ >>>> + >>>> +#define _GNU_SOURCE 1 >>>> +#ifdef __ia64__ >>>> +#define ia64_fpreg ia64_fpreg_DISABLE >>>> +#define pt_all_user_regs pt_all_user_regs_DISABLE >>>> +#endif /* __ia64__ */ >>>> +#include >>>> +#ifdef __ia64__ >>>> +#undef ia64_fpreg >>>> +#undef pt_all_user_regs >>>> +#endif /* __ia64__ */ >>>> +#include >>>> +#include >>>> +#include >>>> +#if defined __i386__ || defined __x86_64__ >>>> +#include >>>> +#endif >>>> + >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> + >>>> +static __attribute__((unused)) pid_t child; >>>> + >>>> +static __attribute__((unused)) void >>>> +cleanup (void) >>>> +{ >>>> + if (child > 0) >>>> + kill (child, SIGKILL); >>>> + child = 0; >>>> +} >>>> + >>>> +static __attribute__((unused)) void >>>> +handler_fail (int signo) >>>> +{ >>>> + cleanup (); >>>> + signal (signo, SIG_DFL); >>>> + raise (signo); >>>> +} >>>> + >>>> +#ifdef __aarch64__ >>>> + >>>> +#define SET_WATCHPOINT set_watchpoint >>>> + >>>> +/* Macros to extract fields from the hardware debug information word. */ >>>> +#define AARCH64_DEBUG_NUM_SLOTS(x) ((x) & 0xff) >>>> +#define AARCH64_DEBUG_ARCH(x) (((x) >> 8) & 0xff) >>>> +/* Macro for the expected version of the ARMv8-A debug architecture. */ >>>> +#define AARCH64_DEBUG_ARCH_V8 0x6 >>>> +#define DR_CONTROL_ENABLED(ctrl) (((ctrl) & 0x1) == 1) >>>> +#define DR_CONTROL_LENGTH(ctrl) (((ctrl) >> 5) & 0xff) >>>> + >>>> +static void >>>> +set_watchpoint (pid_t pid, volatile void *addr, unsigned len_mask) >>>> +{ >>>> + struct user_hwdebug_state dreg_state; >>>> + struct iovec iov; >>>> + long l; >>>> + >>>> + assert (len_mask >= 0x01); >>>> + assert (len_mask <= 0xff); >>>> + >>>> + iov.iov_base = &dreg_state; >>>> + iov.iov_len = sizeof (dreg_state); >>>> + errno = 0; >>>> + l = ptrace (PTRACE_GETREGSET, pid, NT_ARM_HW_WATCH, &iov); >>>> + assert (l == 0); >>>> + assert (AARCH64_DEBUG_ARCH (dreg_state.dbg_info) == AARCH64_DEBUG_ARCH_V8); >>>> + assert (AARCH64_DEBUG_NUM_SLOTS (dreg_state.dbg_info) >= 1); >>>> + >>>> + assert (!DR_CONTROL_ENABLED (dreg_state.dbg_regs[0].ctrl)); >>>> + dreg_state.dbg_regs[0].ctrl |= 1; >>>> + assert ( DR_CONTROL_ENABLED (dreg_state.dbg_regs[0].ctrl)); >>>> + >>>> + assert (DR_CONTROL_LENGTH (dreg_state.dbg_regs[0].ctrl) == 0); >>>> + dreg_state.dbg_regs[0].ctrl |= len_mask << 5; >>>> + assert (DR_CONTROL_LENGTH (dreg_state.dbg_regs[0].ctrl) == len_mask); >>>> + >>>> + dreg_state.dbg_regs[0].ctrl |= 2 << 3; // write >>>> + dreg_state.dbg_regs[0].ctrl |= 2 << 1; // GDB: ???: enabled at el0 >>>> + //printf("ctrl=0x%x\n",dreg_state.dbg_regs[0].ctrl); >>>> + dreg_state.dbg_regs[0].addr = (uintptr_t) addr; >>>> + >>>> + iov.iov_base = &dreg_state; >>>> + iov.iov_len = (offsetof (struct user_hwdebug_state, dbg_regs) >>>> + + sizeof (dreg_state.dbg_regs[0])); >>>> + errno = 0; >>>> + l = ptrace (PTRACE_SETREGSET, pid, NT_ARM_HW_WATCH, &iov); >>>> + if (errno != 0) >>>> + error (1, errno, "PTRACE_SETREGSET: NT_ARM_HW_WATCH"); >>>> + assert (l == 0); >>>> +} >>>> + >>>> +#endif >>>> + >>>> +#ifndef SET_WATCHPOINT >>>> + >>>> +int >>>> +main (void) >>>> +{ >>>> + return 77; >>>> +} >>>> +#else >>>> + >>>> +static volatile long long check; >>>> + >>>> +int >>>> +main (void) >>>> +{ >>>> + pid_t got_pid; >>>> + int i, status; >>>> + long l; >>>> + >>>> + atexit (cleanup); >>>> + signal (SIGABRT, handler_fail); >>>> + signal (SIGINT, handler_fail); >>>> + >>>> + child = fork (); >>>> + assert (child >= 0); >>>> + if (child == 0) >>>> + { >>>> + l = ptrace (PTRACE_TRACEME, 0, NULL, NULL); >>>> + assert (l == 0); >>>> + i = raise (SIGUSR1); >>>> + assert (i == 0); >>>> + check = -1; >>>> + i = raise (SIGUSR2); >>>> + /* NOTREACHED */ >>>> + assert (0); >>>> + } >>>> + >>>> + got_pid = waitpid (child, &status, 0); >>>> + assert (got_pid == child); >>>> + assert (WIFSTOPPED (status)); >>>> + assert (WSTOPSIG (status) == SIGUSR1); >>>> + >>>> + // PASS: >>>> + //SET_WATCHPOINT (child, &check, 0xff); >>>> + // FAIL: >>>> + SET_WATCHPOINT (child, &check, 0x02); >>>> + >>>> + errno = 0; >>>> + l = ptrace (PTRACE_CONT, child, 0l, 0l); >>>> + assert_perror (errno); >>>> + assert (l == 0); >>>> + >>>> + got_pid = waitpid (child, &status, 0); >>>> + assert (got_pid == child); >>>> + assert (WIFSTOPPED (status)); >>>> + if (WSTOPSIG (status) == SIGUSR2) >>>> + { >>>> + /* We missed the watchpoint - unsupported by hardware? */ >>>> + cleanup (); >>>> + return 2; >>>> + } >>>> + assert (WSTOPSIG (status) == SIGTRAP); >>>> + >>>> + cleanup (); >>>> + return 0; >>>> +} >>>> + >>>> +#endif >>>> + >>>> diff --git a/gdb/testsuite/gdb.arch/aarch64-dbreg-contents.exp b/gdb/testsuite/gdb.arch/aarch64-dbreg-contents.exp >>>> new file mode 100644 >>>> index 0000000..6aa23b0 >>>> --- /dev/null >>>> +++ b/gdb/testsuite/gdb.arch/aarch64-dbreg-contents.exp >>>> @@ -0,0 +1,40 @@ >>>> +# Copyright 2018 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 . >>>> +# >>>> +# Make sure that the inferior doesn't assert and exits successfully. >>>> + >>>> +if {![is_aarch64_target]} { >>>> + verbose "Skipping ${gdb_test_file_name}." >>>> + return >>>> +} >>>> + >>>> +standard_testfile .c >>>> + >>>> +if { [gdb_compile ${srcdir}/${subdir}/${srcfile} ${binfile} executable {debug}] != "" } { >>>> + untested "failed to compile" >>>> + return -1 >>>> +} >>>> + >>>> +clean_restart $testfile >>>> + >>>> +set test "run to exit" >>>> +gdb_test_multiple "run" "$test" { >>>> + -re "exited with code 01.*$gdb_prompt $" { >>>> + pass "$test" >>>> + } >>>> + -re "exited normally.*$gdb_prompt $" { >>>> + pass "$test" >>>> + } >>>> +}