From patchwork Wed Feb 3 18:34:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella Netto X-Patchwork-Id: 41931 X-Patchwork-Delegate: azanella@linux.vnet.ibm.com 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 7BF7C39C076A; Wed, 3 Feb 2021 18:34:27 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 7BF7C39C076A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1612377267; bh=70IaNzusCZVAyex45XHmb4dYpGOdPyy/d6PXM5Z4NhE=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=o2VadBWjN3RrhcZt8OzGc2duCbqk9ob95Y1r1WVERpi6g/xfOLE/+Ja5Vk1H658f5 KEejCmaPIZHm9w3qrQloJtxXYUy9VllYvBkHIoZARsLjS/pzypO+DSWrtlA4Yxz0L5 S+DKJlXHrqfR4brO3ksqAk/omrw4+bQDduSBdetk= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mail-qk1-x72a.google.com (mail-qk1-x72a.google.com [IPv6:2607:f8b0:4864:20::72a]) by sourceware.org (Postfix) with ESMTPS id B37E6386F033 for ; Wed, 3 Feb 2021 18:34:24 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org B37E6386F033 Received: by mail-qk1-x72a.google.com with SMTP id a7so652423qkb.13 for ; Wed, 03 Feb 2021 10:34:24 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=70IaNzusCZVAyex45XHmb4dYpGOdPyy/d6PXM5Z4NhE=; b=jQVaiEQgFLkDLo5YWDxfjGJfkS3n+IOKPDo/lOyrbFZCXjrCcO8WVmR/ablaIly3sn ZonrIGt1SOgzLzzURG/ztwAOIWu4B9QR2hOoFgePqGzGPL4gXUdG5U9YMjWUIQtRdk0K 6jqbzQNK+Q2txF03JH+QfljRhulutaUqMr00Yfd5rVlFKtVatebnURqmGxqKjl1drSP/ 8NFUJQS9VbmNnVpPDguDT9O9Q3iX7PAsggmdt5QWzsvC5mm0VIIviVG+EHPf8SBnXx8x uKsIIfnp/TBRplMKhSexdwS3E0qnYTaFh3vURfAHTUtkRJ3oyL+duaP+dDfylzLZ4dhE IDoA== X-Gm-Message-State: AOAM5339Kuc7vToNIcNMHF7o6XoE9ojIvcpTyAE8/XIwOH3wmfpBKjGv aoLqbLddp+BOyIgQUfaRIdzwrFPVcE7NWg== X-Google-Smtp-Source: ABdhPJwxdsLmZuGG1Oa1QXoQMBZ8hUVGuFCmjKveg9tiE/8g8evwwcfqqvLm6rRjDSMHPbmJi7QK5A== X-Received: by 2002:a37:4d8d:: with SMTP id a135mr3953138qkb.51.1612377264146; Wed, 03 Feb 2021 10:34:24 -0800 (PST) Received: from localhost.localdomain ([177.194.48.209]) by smtp.googlemail.com with ESMTPSA id h63sm2051419qtd.14.2021.02.03.10.34.22 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 03 Feb 2021 10:34:23 -0800 (PST) To: libc-alpha@sourceware.org Subject: [PATCH 3/3] pthread: Remove alloca usage from __sem_check_add_mapping Date: Wed, 3 Feb 2021 15:34:14 -0300 Message-Id: <20210203183414.571813-3-adhemerval.zanella@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210203183414.571813-1-adhemerval.zanella@linaro.org> References: <20210203183414.571813-1-adhemerval.zanella@linaro.org> MIME-Version: 1.0 X-Spam-Status: No, score=-13.5 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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: Adhemerval Zanella via Libc-alpha From: Adhemerval Zanella Netto Reply-To: Adhemerval Zanella Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" sem_open already returns EINVAL for input names larger than NAME_MAX, so it can assume the largest name length to with tfind. Checked on x86_64-linux-gnu. --- sysdeps/pthread/sem_routines.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) diff --git a/sysdeps/pthread/sem_routines.c b/sysdeps/pthread/sem_routines.c index 78d9364ebd..d5e2f56547 100644 --- a/sysdeps/pthread/sem_routines.c +++ b/sysdeps/pthread/sem_routines.c @@ -31,6 +31,15 @@ struct inuse_sem char name[]; }; +struct search_sem +{ + dev_t dev; + ino_t ino; + int refcnt; + sem_t *sem; + char name[NAME_MAX]; +}; + /* Comparison function for search of existing mapping. */ static int sem_search (const void *a, const void *b) @@ -61,6 +70,9 @@ sem_t * __sem_check_add_mapping (const char *name, int fd, sem_t *existing) { size_t namelen = strlen (name); + if (namelen > NAME_MAX) + return NULL; + sem_t *result = SEM_FAILED; /* Get the information about the file. */ @@ -71,13 +83,12 @@ __sem_check_add_mapping (const char *name, int fd, sem_t *existing) lll_lock (sem_mappings_lock, LLL_PRIVATE); /* Search for an existing mapping given the information we have. */ - struct inuse_sem *fake; - fake = (struct inuse_sem *) alloca (sizeof (*fake) + namelen); - memcpy (fake->name, name, namelen); - fake->dev = st.st_dev; - fake->ino = st.st_ino; + struct search_sem fake; + memcpy (fake.name, name, namelen); + fake.dev = st.st_dev; + fake.ino = st.st_ino; - struct inuse_sem **foundp = __tfind (fake, &sem_mappings, sem_search); + struct inuse_sem **foundp = __tfind (&fake, &sem_mappings, sem_search); if (foundp != NULL) { /* There is already a mapping. Use it. */