From patchwork Tue Dec 4 22:48:02 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Philippe Waroquiers X-Patchwork-Id: 30544 Received: (qmail 116496 invoked by alias); 4 Dec 2018 22:49:24 -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 115941 invoked by uid 89); 4 Dec 2018 22:48:40 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-27.6 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_LOW, SPF_PASS, TIME_LIMIT_EXCEEDED autolearn=unavailable version=3.3.2 spammy=startup, HContent-Transfer-Encoding:8bit X-HELO: mailsec111.isp.belgacom.be Received: from mailsec111.isp.belgacom.be (HELO mailsec111.isp.belgacom.be) (195.238.20.107) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 04 Dec 2018 22:48:21 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=skynet.be; i=@skynet.be; q=dns/txt; s=securemail; t=1543963690; x=1575499690; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=6EC9GJDHC+lOFv7t4Hh2KjiGZCfJfKUtj1vTCn7Rc40=; b=DOlPMCbtY3VtOprXap4A6O+pQx9SgiBUdIqPfVszx0XyDzoI9pd9LAHn 51lsnenrB8ZfOo20ae+aS63wyb7FGg==; Received: from 184.205-67-87.adsl-dyn.isp.belgacom.be (HELO md.home) ([87.67.205.184]) by relay.skynet.be with ESMTP/TLS/DHE-RSA-AES128-GCM-SHA256; 04 Dec 2018 23:48:07 +0100 From: Philippe Waroquiers To: gdb-patches@sourceware.org Cc: Philippe Waroquiers Subject: [RFA] Fix a (one shot small) leak in language.c Date: Tue, 4 Dec 2018 23:48:02 +0100 Message-Id: <20181204224802.8846-1-philippe.waroquiers@skynet.be> MIME-Version: 1.0 X-IsSubscribed: yes Valgrind detects the following leak: ==28395== VALGRIND_GDB_ERROR_BEGIN ==28395== 5 bytes in 1 blocks are definitely lost in loss record 20 of 2,770 ==28395== at 0x4C2BE2D: malloc (vg_replace_malloc.c:299) ==28395== by 0x41D9E7: xmalloc (common-utils.c:44) ==28395== by 0x78BF39: xstrdup (xstrdup.c:34) ==28395== by 0x51F1AC: _initialize_language() (language.c:1175) ==28395== by 0x6B3356: initialize_all_files() (init.c:308) ==28395== by 0x66D194: gdb_init(char*) (top.c:2159) ==28395== by 0x554C11: captured_main_1 (main.c:863) ==28395== by 0x554C11: captured_main (main.c:1167) ==28395== by 0x554C11: gdb_main(captured_main_args*) (main.c:1193) ==28395== by 0x29D837: main (gdb.c:32) ==28395== ==28395== VALGRIND_GDB_ERROR_END This is a very small leak (1 block/5 bytes), happening only once per GDB startup as far as I can see. But this fix make the nr of leaking GDB in the testsuite decreasing from 628 to 566. It is unclear why a xstrdup-ed value is assigned to 'language' at initialization time, while a static "auto" string is assigned as part of the set_language_command. So, that shows that it is ok to initialize 'language' directly with "auto". Also, I cannot find any place where 'language' is xfree-d. No leak was detected for 'range' and 'case_sensitive', but similarly, no indication why a static string cannot be assigned. Regression-tested on debian/x86_64. Also, full testsuite run under valgrind, less tests leaking, and no dangling pointer problem detected. gdb/ChangeLog 2018-12-04 Philippe Waroquiers * language.c (_initialize_language): Fix leak by assigning a static string to language. Same for range and case_sensitive, even if no leak is detected for these variables. --- gdb/language.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/gdb/language.c b/gdb/language.c index e2f400161b..0ec61c3f5a 100644 --- a/gdb/language.c +++ b/gdb/language.c @@ -1172,9 +1172,9 @@ For Fortran the default is off; for other languages the default is on."), add_set_language_command (); - language = xstrdup ("auto"); - range = xstrdup ("auto"); - case_sensitive = xstrdup ("auto"); + language = "auto"; + range = "auto"; + case_sensitive = "auto"; /* Have the above take effect. */ set_language (language_auto);