From patchwork Tue Oct 11 20:55:21 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Machado X-Patchwork-Id: 16427 Received: (qmail 110742 invoked by alias); 11 Oct 2016 20:55:40 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 110724 invoked by uid 89); 11 Oct 2016 20:55:40 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL, BAYES_00, RCVD_IN_DNSWL_NONE, SPF_PASS, URIBL_RED autolearn=ham version=3.3.2 spammy=ua, Hx-languages-length:3604, optimizing X-HELO: relay1.mentorg.com Received: from relay1.mentorg.com (HELO relay1.mentorg.com) (192.94.38.131) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 11 Oct 2016 20:55:29 +0000 Received: from svr-orw-fem-02x.mgc.mentorg.com ([147.34.96.206] helo=SVR-ORW-FEM-02.mgc.mentorg.com) by relay1.mentorg.com with esmtp id 1bu45A-0004Rs-6G from Luis_Gustavo@mentor.com ; Tue, 11 Oct 2016 13:55:28 -0700 Received: from Opsys.world.mentorg.com (147.34.91.1) by svr-orw-fem-02.mgc.mentorg.com (147.34.96.168) with Microsoft SMTP Server id 14.3.224.2; Tue, 11 Oct 2016 13:55:27 -0700 From: Luis Machado To: , Subject: [PATCH v2] Fixup gdb.python/py-value.exp for bare-metal aarch64-elf Date: Tue, 11 Oct 2016 15:55:21 -0500 Message-ID: <1476219321-10659-1-git-send-email-lgustavo@codesourcery.com> MIME-Version: 1.0 X-IsSubscribed: yes I noticed that testing aarch64-elf gdb with a physical board ran into issues with gdb.python/py-value.exp. Further investigation showed that we were actually trying to dereference a NULL pointer (argv) when trying to access argv[0]. Being bare-metal, argv is not guaranteed to be valid. So we need to make sure argv is sane before accessing argv[0]. The following patch fixes up the test program to check for a NULL argv and also improves the testcase a bit so it doesn't have to work with a hardcoded argc value. Regression-tested on x86-64 Ubuntu 16.04. I've incorporated Yao's feedback in v2. Does it look OK? gdb/testsuite/ChangeLog: 2016-10-11 Luis Machado * gdb.python/py-value.c (main): Check if argv is NULL before using it. * gdb.python/py-value.exp (test_value_in_inferior): Don't use a hardcoded argc value. --- gdb/testsuite/ChangeLog | 6 ++++++ gdb/testsuite/gdb.python/py-value.c | 10 +++++++++- gdb/testsuite/gdb.python/py-value.exp | 5 +++-- 3 files changed, 18 insertions(+), 3 deletions(-) diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index b4ccd4a..2ed2c9c 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2016-10-11 Luis Machado + + * gdb.python/py-value.c (main): Check if argv is NULL before using it. + * gdb.python/py-value.exp (test_value_in_inferior): Adjust initial + argc value based on the existence of argv. + 2016-10-11 Jan Kratochvil * gdb.arch/powerpc-prologue.c (optimized_1): New declaration. diff --git a/gdb/testsuite/gdb.python/py-value.c b/gdb/testsuite/gdb.python/py-value.c index 586a0fd..8a8ace6 100644 --- a/gdb/testsuite/gdb.python/py-value.c +++ b/gdb/testsuite/gdb.python/py-value.c @@ -82,7 +82,7 @@ char **save_argv; int main (int argc, char *argv[]) { - char *cp = argv[0]; /* Prevent gcc from optimizing argv[] out. */ + char *cp; struct s s; union u u; PTR x = &s; @@ -99,6 +99,14 @@ main (int argc, char *argv[]) const char *sn = 0; struct str *xstr; + /* Prevent gcc from optimizing argv[] out. */ + + /* We also check for a NULL argv in case we are dealing with a target + executing in a freestanding environment, therefore there are no + guarantees about argc or argv. */ + if (argv != NULL) + cp = argv[0]; + s.a = 3; s.b = 5; u.a = 7; diff --git a/gdb/testsuite/gdb.python/py-value.exp b/gdb/testsuite/gdb.python/py-value.exp index 662c5b4..f31096b 100644 --- a/gdb/testsuite/gdb.python/py-value.exp +++ b/gdb/testsuite/gdb.python/py-value.exp @@ -274,15 +274,16 @@ proc test_value_in_inferior {} { gdb_test "python inval2 = inval+1" "gdb.MemoryError: Cannot access memory at address 0x0.*" $test gdb_test "python inval.fetch_lazy ()" "gdb.MemoryError: Cannot access memory at address 0x0.*" $test } + set argc_value [get_integer_valueof "argc" 0] gdb_test "python argc_lazy = gdb.parse_and_eval('argc')" gdb_test "python argc_notlazy = gdb.parse_and_eval('argc')" gdb_test "python argc_notlazy.fetch_lazy()" gdb_test "python print (argc_lazy.is_lazy)" "True" gdb_test "python print (argc_notlazy.is_lazy)" "False" - gdb_test "print argc" " = 1" "sanity check argc" + gdb_test "print argc" " = $argc_value" "sanity check argc" gdb_test "python print (argc_lazy.is_lazy)" "\r\nTrue" gdb_test_no_output "set argc=2" - gdb_test "python print (argc_notlazy)" "\r\n1" + gdb_test "python print (argc_notlazy)" "\r\n$argc_value" gdb_test "python print (argc_lazy)" "\r\n2" gdb_test "python print (argc_lazy.is_lazy)" "False"