From patchwork Mon Jun 12 00:47:52 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: 1793735 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=sourceware.org (client-ip=8.43.85.97; helo=sourceware.org; envelope-from=libc-alpha-bounces+incoming=patchwork.ozlabs.org@sourceware.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.a=rsa-sha256 header.s=default header.b=F41Y68ts; dkim-atps=neutral Received: from sourceware.org (ip-8-43-85-97.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4QfY2R1mnPz20Vx for ; Mon, 12 Jun 2023 10:48:15 +1000 (AEST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id D5F54385770A for ; Mon, 12 Jun 2023 00:48:10 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D5F54385770A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1686530890; bh=2zd0d5rlj+ZtyDE4z0psSjOIMQ6evAgKnIwjW5/yMDE=; h=Date:To:Cc:Subject:References:In-Reply-To:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From:Reply-To:From; b=F41Y68tsHkLhWsJxDliNiSgKByqKhWjnEDR7nqKI0zoB5TOkDcN8n6qDKGxVCLXLW SyZoF1/4D/q6LJ2P+IH/okChv8yCH81JrGuYIgNIX0UzcGrlPCUCMS/XhmBazRk+W5 Uh4k8InZMEX0U2ze6HnUBh5E47eph32cIuHpX/UY= 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 2BCC13858D33 for ; Mon, 12 Jun 2023 00:47:54 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 2BCC13858D33 Received: from tarta.nabijaczleweli.xyz (unknown [192.168.1.250]) by tarta.nabijaczleweli.xyz (Postfix) with ESMTPSA id 209A3582; Mon, 12 Jun 2023 02:47:53 +0200 (CEST) Date: Mon, 12 Jun 2023 02:47:52 +0200 To: Adhemerval Zanella Netto Cc: libc-alpha@sourceware.org, Carlos O'Donell Subject: [PATCH v7 2/3] posix: regexec(): fix REG_STARTEND, pmatch->rm_so != 0 w/^ anchor Message-ID: <695cd581035b59c759477b806640ee0b70df05f7.1686530834.git.nabijaczleweli@nabijaczleweli.xyz> References: <4450a8f3-3774-5bbc-ebe2-64d8a25fdacc@linaro.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4450a8f3-3774-5bbc-ebe2-64d8a25fdacc@linaro.org> User-Agent: NeoMutt/20230517 X-Spam-Status: No, score=-10.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_INFOUSMEBIZ, PDS_RDNS_DYNAMIC_FP, 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+incoming=patchwork.ozlabs.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 --- 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; }