From patchwork Sat Apr 22 02:23:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Ahelenia_Ziemia=C5=84ska?= X-Patchwork-Id: 68156 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id B0CFC3858C50 for ; Sat, 22 Apr 2023 02:23:41 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B0CFC3858C50 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1682130221; bh=E+huAQvgC3kf5+/LWJU+4WKRFVT96C/mT11Lkor/mxE=; h=Date:To:Subject:References:In-Reply-To:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=bTuRfsUbTgRMuuUlGlpiQJ0OEZVBL1Clpi1itbRa8UfzByMgxcnkmZ6ZmJfouGP8i oDjC83IAgxBeH92sDT4qk3KmhmpWM8IfoXFqORaZU+QVHN5GmnxSQ3khjKcW/eexpr WszQ7d3iNX01REnP+9R/Z3Lv3hcFqRWG9vFdIb+U= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from tarta.nabijaczleweli.xyz (unknown [139.28.40.42]) by sourceware.org (Postfix) with ESMTP id B627C3857713 for ; Sat, 22 Apr 2023 02:23:19 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org B627C3857713 Received: from tarta.nabijaczleweli.xyz (unknown [192.168.1.250]) by tarta.nabijaczleweli.xyz (Postfix) with ESMTPSA id 30CF865CE for ; Sat, 22 Apr 2023 04:23:19 +0200 (CEST) Date: Sat, 22 Apr 2023 04:23:18 +0200 To: libc-alpha@sourceware.org Subject: [PATCH 3/3] posix: regexec(): fix REG_STARTEND, pmatch->rm_so != 0 w/^ anchor Message-ID: <5d473c3798f3e02809d86007d4f291edd07c9cda.1682130047.git.nabijaczleweli@nabijaczleweli.xyz> References: <6ae8f638ecd1a0f0d76a104c8903baf96ecd317a.1682130047.git.nabijaczleweli@nabijaczleweli.xyz> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <6ae8f638ecd1a0f0d76a104c8903baf96ecd317a.1682130047.git.nabijaczleweli@nabijaczleweli.xyz> User-Agent: NeoMutt/20230407 X-Spam-Status: No, score=-9.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_INFOUSMEBIZ, RDNS_DYNAMIC, SPF_HELO_PASS, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: =?utf-8?b?0L3QsNCxIHZpYSBMaWJjLWFscGhh?= From: =?utf-8?q?Ahelenia_Ziemia=C5=84ska?= Reply-To: =?utf-8?b?0L3QsNCx?= Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" re_search_internal () starts with /* If initial states with non-begbuf contexts have no elements, the regex must be anchored. If preg->newline_anchor is set, we'll never use init_state_nl, so do not check it. */ if (dfa->init_state->nodes.nelem == 0 && dfa->init_state_word->nodes.nelem == 0 && (dfa->init_state_nl->nodes.nelem == 0 || !preg->newline_anchor)) { if (start != 0 && last_start != 0) return REG_NOMATCH; start = last_start = 0; } and heretofor start and last_start (for example when "abc", {1, 2}, so matching just the "b") were != 0, and the return was taken for a "^b" regex, which is erroneous. Fix this by giving re_search_internal (string+rm_so, start=0), then fixing up the returned matches in an after-pass. This brings us to compatibility with the BSD spec and implementations. Signed-off-by: Ahelenia Ziemiańska --- Please keep me in CC, as I'm not subscribed. posix/regexec.c | 41 ++++++++++++++++++++++++++++------------- 1 file changed, 28 insertions(+), 13 deletions(-) diff --git a/posix/regexec.c b/posix/regexec.c index bd0cd412d0..2ef868e1f6 100644 --- a/posix/regexec.c +++ b/posix/regexec.c @@ -187,38 +187,53 @@ static reg_errcode_t extend_buffers (re_match_context_t *mctx, int min_len); string; if REG_NOTEOL is set, then $ does not match at the end. Return 0 if a match is found, REG_NOMATCH if not, REG_BADPAT if - EFLAGS is invalid. */ + EFLAGS is invalid. + + If REG_STARTEND, the bounds are + [STRING + PMATCH->rm_so, STRING + PMATCH->rm_eo) + instead of the usual + [STRING, STRING + strlen(STRING)), + but returned matches are still referenced to STRING, + and matching is unaffected (i.e. "abc", {1, 2} matches regex "^b$"). + re_search_internal () has a built-in assumption of + (start != 0) <=> (^ doesn't match), so give it a truncated view + and fix up the matches afterward. */ int regexec (const regex_t *__restrict preg, const char *__restrict string, size_t nmatch, regmatch_t pmatch[_REGEX_NELTS (nmatch)], int eflags) { reg_errcode_t err; - Idx start, length; + Idx startoff = 0, length; re_dfa_t *dfa = preg->buffer; + size_t i = 0; if (eflags & ~(REG_NOTBOL | REG_NOTEOL | REG_STARTEND)) return REG_BADPAT; if (eflags & REG_STARTEND) { - start = pmatch[0].rm_so; - length = pmatch[0].rm_eo; + startoff = pmatch[0].rm_so; + string += startoff; + length = pmatch[0].rm_eo - startoff; } else - { - start = 0; - length = strlen (string); - } + length = strlen (string); lock_lock (dfa->lock); if (preg->no_sub) - err = re_search_internal (preg, string, length, start, length, - length, 0, NULL, eflags); - else - err = re_search_internal (preg, string, length, start, length, - length, nmatch, pmatch, eflags); + nmatch = 0; + err = re_search_internal (preg, string, length, 0, length, + length, nmatch, pmatch, eflags); lock_unlock (dfa->lock); + + if (err == REG_NOERROR && startoff) + for (i = 0; i < nmatch; ++i) + if (pmatch[i].rm_so != -1) + { + pmatch[i].rm_so += startoff; + pmatch[i].rm_eo += startoff; + } return err != REG_NOERROR; }