From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28A80C433E1 for ; Mon, 18 May 2020 18:15:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0AABF20715 for ; Mon, 18 May 2020 18:15:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589825736; bh=zC7WtYufx/aBvsGLXAfcPdRS54JeTpN1FQTW+VKOSAU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wSCbcJxHMZXW8QG5/yLnUgToqSJXJIFaC1LHHD2m4fNKnwy00DZ42Et2VaFQ7PqxB JhTzA9HA3w87bQCDM0hHgXDLUgLWQ/qcYhZyxTP4SmYn/+torJ70ZClMxG/UMHTlgR oXyOfVthlG9SpPR8qJyU2pANz1XIeQvsg07iHtNg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730996AbgERR7e (ORCPT ); Mon, 18 May 2020 13:59:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:40126 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732070AbgERR7d (ORCPT ); Mon, 18 May 2020 13:59:33 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C1F3420826; Mon, 18 May 2020 17:59:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589824772; bh=zC7WtYufx/aBvsGLXAfcPdRS54JeTpN1FQTW+VKOSAU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mub2V2qBjTPkEtJuFXGRQ0B8UCaitCdSBiDQw09JPoryERXBGB/4z1VkWNgUjFveB PEaO0Lef2PA9cHjEj9yb9ISNrgfGOy6p/maV12mv135wLz8wSRTLF2P27NPTyyYOGl OXNkhSLExGqHuBLu3K8fQuTv/zc45pxz19fKwbbE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrii Nakryiko , Alexei Starovoitov Subject: [PATCH 5.4 145/147] libbpf: Extract and generalize CPU mask parsing logic Date: Mon, 18 May 2020 19:37:48 +0200 Message-Id: <20200518173531.002979581@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200518173513.009514388@linuxfoundation.org> References: <20200518173513.009514388@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Andrii Nakryiko commit 6803ee25f0ead1e836808acb14396bb9a9849113 upstream. This logic is re-used for parsing a set of online CPUs. Having it as an isolated piece of code working with input string makes it conveninent to test this logic as well. While refactoring, also improve the robustness of original implementation. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20191212013548.1690564-1-andriin@fb.com Signed-off-by: Greg Kroah-Hartman --- tools/lib/bpf/libbpf.c | 128 ++++++++++++++++++++++++++-------------- tools/lib/bpf/libbpf_internal.h | 2 2 files changed, 87 insertions(+), 43 deletions(-) --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -5905,62 +5905,104 @@ void bpf_program__bpil_offs_to_addr(stru } } -int libbpf_num_possible_cpus(void) +int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz) { - static const char *fcpu = "/sys/devices/system/cpu/possible"; - int len = 0, n = 0, il = 0, ir = 0; - unsigned int start = 0, end = 0; - int tmp_cpus = 0; - static int cpus; - char buf[128]; - int error = 0; - int fd = -1; + int err = 0, n, len, start, end = -1; + bool *tmp; - tmp_cpus = READ_ONCE(cpus); - if (tmp_cpus > 0) - return tmp_cpus; + *mask = NULL; + *mask_sz = 0; + + /* Each sub string separated by ',' has format \d+-\d+ or \d+ */ + while (*s) { + if (*s == ',' || *s == '\n') { + s++; + continue; + } + n = sscanf(s, "%d%n-%d%n", &start, &len, &end, &len); + if (n <= 0 || n > 2) { + pr_warning("Failed to get CPU range %s: %d\n", s, n); + err = -EINVAL; + goto cleanup; + } else if (n == 1) { + end = start; + } + if (start < 0 || start > end) { + pr_warning("Invalid CPU range [%d,%d] in %s\n", + start, end, s); + err = -EINVAL; + goto cleanup; + } + tmp = realloc(*mask, end + 1); + if (!tmp) { + err = -ENOMEM; + goto cleanup; + } + *mask = tmp; + memset(tmp + *mask_sz, 0, start - *mask_sz); + memset(tmp + start, 1, end - start + 1); + *mask_sz = end + 1; + s += len; + } + if (!*mask_sz) { + pr_warning("Empty CPU range\n"); + return -EINVAL; + } + return 0; +cleanup: + free(*mask); + *mask = NULL; + return err; +} + +int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz) +{ + int fd, err = 0, len; + char buf[128]; fd = open(fcpu, O_RDONLY); if (fd < 0) { - error = errno; - pr_warning("Failed to open file %s: %s\n", - fcpu, strerror(error)); - return -error; + err = -errno; + pr_warning("Failed to open cpu mask file %s: %d\n", fcpu, err); + return err; } len = read(fd, buf, sizeof(buf)); close(fd); if (len <= 0) { - error = len ? errno : EINVAL; - pr_warning("Failed to read # of possible cpus from %s: %s\n", - fcpu, strerror(error)); - return -error; - } - if (len == sizeof(buf)) { - pr_warning("File %s size overflow\n", fcpu); - return -EOVERFLOW; + err = len ? -errno : -EINVAL; + pr_warning("Failed to read cpu mask from %s: %d\n", fcpu, err); + return err; + } + if (len >= sizeof(buf)) { + pr_warning("CPU mask is too big in file %s\n", fcpu); + return -E2BIG; } buf[len] = '\0'; - for (ir = 0, tmp_cpus = 0; ir <= len; ir++) { - /* Each sub string separated by ',' has format \d+-\d+ or \d+ */ - if (buf[ir] == ',' || buf[ir] == '\0') { - buf[ir] = '\0'; - n = sscanf(&buf[il], "%u-%u", &start, &end); - if (n <= 0) { - pr_warning("Failed to get # CPUs from %s\n", - &buf[il]); - return -EINVAL; - } else if (n == 1) { - end = start; - } - tmp_cpus += end - start + 1; - il = ir + 1; - } - } - if (tmp_cpus <= 0) { - pr_warning("Invalid #CPUs %d from %s\n", tmp_cpus, fcpu); - return -EINVAL; + return parse_cpu_mask_str(buf, mask, mask_sz); +} + +int libbpf_num_possible_cpus(void) +{ + static const char *fcpu = "/sys/devices/system/cpu/possible"; + static int cpus; + int err, n, i, tmp_cpus; + bool *mask; + + tmp_cpus = READ_ONCE(cpus); + if (tmp_cpus > 0) + return tmp_cpus; + + err = parse_cpu_mask_file(fcpu, &mask, &n); + if (err) + return err; + + tmp_cpus = 0; + for (i = 0; i < n; i++) { + if (mask[i]) + tmp_cpus++; } + free(mask); WRITE_ONCE(cpus, tmp_cpus); return tmp_cpus; --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -63,6 +63,8 @@ do { \ #define pr_info(fmt, ...) __pr(LIBBPF_INFO, fmt, ##__VA_ARGS__) #define pr_debug(fmt, ...) __pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__) +int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz); +int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz); int libbpf__load_raw_btf(const char *raw_types, size_t types_len, const char *str_sec, size_t str_len);