From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 18068 invoked by alias); 2 Oct 2013 11:51:29 -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 18054 invoked by uid 89); 2 Oct 2013 11:51:29 -0000 Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 02 Oct 2013 11:51:29 +0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.3 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r92BpRJ9017877 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 2 Oct 2013 07:51:27 -0400 Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r92BpP74016835 for ; Wed, 2 Oct 2013 07:51:26 -0400 Message-ID: <524C08BD.2030508@redhat.com> Date: Wed, 02 Oct 2013 11:51:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: gdb-patches@sourceware.org Subject: Re: [PATCH 1/2] Make catch-syscall.exp work with "target remote". A.k.a., teach the testsuite that GDBserver reliably reports program exits. References: <1380309731-29881-1-git-send-email-palves@redhat.com> <1380309731-29881-2-git-send-email-palves@redhat.com> In-Reply-To: <1380309731-29881-2-git-send-email-palves@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-SW-Source: 2013-10/txt/msg00091.txt.bz2 Now applied as well (after patch 2/2), as below. ----- Subject: Teach the testsuite that GDBserver reliably reports program exits. Running catch-syscall.exp against a gdbserver that actually supports it, we get: FAIL: gdb.base/catch-syscall.exp: continue until exit (the program exited) FAIL: gdb.base/catch-syscall.exp: continue until exit (the program exited) FAIL: gdb.base/catch-syscall.exp: continue until exit (the program exited) FAIL: gdb.base/catch-syscall.exp: continue until exit at catch syscall with unused syscall (mlock) (the program exited) FAIL: gdb.base/catch-syscall.exp: continue until exit (the program exited) The fail pattern is: Catchpoint 2 (call to syscall exit_group), 0x000000323d4baa29 in _exit () from /lib64/libc.so.6 (gdb) PASS: gdb.base/catch-syscall.exp: program has called exit_group delete breakpoints Delete all breakpoints? (y or n) y (gdb) info breakpoints No breakpoints or watchpoints. (gdb) break exit Breakpoint 3 at 0x323d438bf0 (gdb) continue Continuing. [Inferior 1 (process 21081) exited normally] That "break exit" + "continue" comes from: > # gdb_continue_to_end: > # The case where the target uses stubs has to be handled specially. If a > # stub is used, we set a breakpoint at exit because we cannot rely on > # exit() behavior of a remote target. > # The native-gdbserver.exp board, used to test against gdbserver in "target remote" mode, triggers that case ($use_gdb_stub is true). So gdb_continue_to_end doesn't work for catch-syscall.exp as here we catch the exit_group and continue from that, expecting to see a real program exit. I was about to post a patch that changes catch-syscall.exp to call a new function that just always does what gdb_continue_to_end does in the !$use_gdb_stub case. But, since GDBserver doesn't really need this, in the end I thought it better to teach the testsuite that there are stubs that know how to report program exits, by adding a new "exit_is_reliable" board variable that then gdb_continue_to_end checks. Tested on x86_64 Fedora 17, native and gdbserver. gdb/testsuite/ 2013-10-02 Pedro Alves * README (Board Settings): Document "exit_is_reliable". * lib/gdb.exp (gdb_continue_to_end): Check whether the board says running to exit reliably reports program exits. * boards/native-gdbserver.exp: Set exit_is_reliable in the board info. * boards/native-stdio-gdbserver.exp: Likewise. --- gdb/testsuite/README | 9 +++++++++ gdb/testsuite/boards/native-gdbserver.exp | 1 + gdb/testsuite/boards/native-stdio-gdbserver.exp | 1 + gdb/testsuite/lib/gdb.exp | 21 +++++++++++++++------ 4 files changed, 26 insertions(+), 6 deletions(-) diff --git a/gdb/testsuite/README b/gdb/testsuite/README index 4d369c5..ec91b14 100644 --- a/gdb/testsuite/README +++ b/gdb/testsuite/README @@ -247,6 +247,15 @@ use_gdb_stub The tests are running with a GDB stub. +exit_is_reliable + + Set to true if GDB can assume that letting the program run to end + reliably results in program exits being reported as such, as opposed + to, e.g., the program ending in an infinite loop or the board + crashing/resetting. If not set, this defaults to $use_gdb_stub. In + other words, native targets are assumed reliable by default, and + remote stubs assumed unreliable. + gdb,predefined_tsv The predefined trace state variables the board has. diff --git a/gdb/testsuite/boards/native-gdbserver.exp b/gdb/testsuite/boards/native-gdbserver.exp index 6c1430f..ab239ec 100644 --- a/gdb/testsuite/boards/native-gdbserver.exp +++ b/gdb/testsuite/boards/native-gdbserver.exp @@ -31,6 +31,7 @@ set_board_info noargs 1 set_board_info sockethost "localhost:" set_board_info use_gdb_stub 1 +set_board_info exit_is_reliable 1 # We will be using the standard GDB remote protocol. set_board_info gdb_protocol "remote" diff --git a/gdb/testsuite/boards/native-stdio-gdbserver.exp b/gdb/testsuite/boards/native-stdio-gdbserver.exp index 3b99909..a093904 100644 --- a/gdb/testsuite/boards/native-stdio-gdbserver.exp +++ b/gdb/testsuite/boards/native-stdio-gdbserver.exp @@ -34,6 +34,7 @@ set_board_info sockethost "stdio" set_board_info gdb,socketport "" set_board_info gdb,get_remote_address ${board}_get_remote_address set_board_info use_gdb_stub 1 +set_board_info exit_is_reliable 1 # We will be using the standard GDB remote protocol. set_board_info gdb_protocol "remote" diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp index 5e3331a..6c9948f 100644 --- a/gdb/testsuite/lib/gdb.exp +++ b/gdb/testsuite/lib/gdb.exp @@ -3806,11 +3806,8 @@ proc gdb_get_line_number { text { file "" } } { return $found } -# gdb_continue_to_end: -# The case where the target uses stubs has to be handled specially. If a -# stub is used, we set a breakpoint at exit because we cannot rely on -# exit() behavior of a remote target. -# +# Continue the program until it ends. +# # MSSG is the error message that gets printed. If not given, a # default is used. # COMMAND is the command to invoke. If not given, "continue" is @@ -3833,7 +3830,19 @@ proc gdb_continue_to_end {{mssg ""} {command continue} {allow_extra 0}} { } else { set extra "" } - if $use_gdb_stub { + + # By default, we don't rely on exit() behavior of remote stubs -- + # it's common for exit() to be implemented as a simple infinite + # loop, or a forced crash/reset. For native targets, by default, we + # assume process exit is reported as such. If a non-reliable target + # is used, we set a breakpoint at exit, and continue to that. + if { [target_info exists exit_is_reliable] } { + set exit_is_reliable [target_info exit_is_reliable] + } else { + set exit_is_reliable [expr ! $use_gdb_stub] + } + + if { ! $exit_is_reliable } { if {![gdb_breakpoint "exit"]} { return 0 }