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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 5D0CBC47083 for ; Tue, 1 Jun 2021 02:57:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3F4E460FF0 for ; Tue, 1 Jun 2021 02:57:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232805AbhFAC6w (ORCPT ); Mon, 31 May 2021 22:58:52 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:3483 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232699AbhFAC6p (ORCPT ); Mon, 31 May 2021 22:58:45 -0400 Received: from dggeme759-chm.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4FvGvt3BrwzYqvk; Tue, 1 Jun 2021 10:54:18 +0800 (CST) Received: from localhost.localdomain (10.69.192.56) by dggeme759-chm.china.huawei.com (10.3.19.105) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Tue, 1 Jun 2021 10:57:01 +0800 From: Tian Tao To: , , , CC: Tian Tao , Andy Shevchenko , "Rafael J. Wysocki" Subject: [PATCH 1/2] topology: use bin_attribute to avoid buff overflow Date: Tue, 1 Jun 2021 10:56:49 +0800 Message-ID: <1622516210-10886-2-git-send-email-tiantao6@hisilicon.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1622516210-10886-1-git-send-email-tiantao6@hisilicon.com> References: <1622516210-10886-1-git-send-email-tiantao6@hisilicon.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.69.192.56] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggeme759-chm.china.huawei.com (10.3.19.105) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Reading sys/devices/system/cpu/cpuX/topology/ returns cpu topology. However, the size of this file is limited to PAGE_SIZE because of the limitation for sysfs attribute. so we use bin_attribute instead of attribute to avoid NR_CPUS too big to cause buff overflow. This patch is based on the following discussion. https://www.spinics.net/lists/linux-doc/msg95921.html Signed-off-by: Tian Tao Cc: Andrew Morton Cc: Andy Shevchenko Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" --- drivers/base/topology.c | 115 ++++++++++++++++++++++++++---------------------- include/linux/bitmap.h | 3 ++ include/linux/cpumask.h | 25 +++++++++++ lib/bitmap.c | 34 ++++++++++++++ 4 files changed, 125 insertions(+), 52 deletions(-) diff --git a/drivers/base/topology.c b/drivers/base/topology.c index 4d254fc..013edbb 100644 --- a/drivers/base/topology.c +++ b/drivers/base/topology.c @@ -21,25 +21,27 @@ static ssize_t name##_show(struct device *dev, \ return sysfs_emit(buf, "%d\n", topology_##name(dev->id)); \ } -#define define_siblings_show_map(name, mask) \ -static ssize_t name##_show(struct device *dev, \ - struct device_attribute *attr, char *buf) \ -{ \ - return cpumap_print_to_pagebuf(false, buf, topology_##mask(dev->id));\ +#define define_siblings_read_func(name, mask) \ +static ssize_t name##_read(struct file *file, struct kobject *kobj, \ + struct bin_attribute *attr, char *buf, \ + loff_t off, size_t count) \ +{ \ + struct device *dev = kobj_to_dev(kobj); \ + \ + return cpumap_print_to_buf(false, buf, topology_##mask(dev->id), \ + off, count); \ +} \ + \ +static ssize_t name##_list_read(struct file *file, struct kobject *kobj, \ + struct bin_attribute *attr, char *buf, \ + loff_t off, size_t count) \ +{ \ + struct device *dev = kobj_to_dev(kobj); \ + \ + return cpumap_print_to_buf(true, buf, topology_##mask(dev->id), \ + off, count); \ } -#define define_siblings_show_list(name, mask) \ -static ssize_t name##_list_show(struct device *dev, \ - struct device_attribute *attr, \ - char *buf) \ -{ \ - return cpumap_print_to_pagebuf(true, buf, topology_##mask(dev->id));\ -} - -#define define_siblings_show_func(name, mask) \ - define_siblings_show_map(name, mask); \ - define_siblings_show_list(name, mask) - define_id_show_func(physical_package_id); static DEVICE_ATTR_RO(physical_package_id); @@ -49,71 +51,80 @@ static DEVICE_ATTR_RO(die_id); define_id_show_func(core_id); static DEVICE_ATTR_RO(core_id); -define_siblings_show_func(thread_siblings, sibling_cpumask); -static DEVICE_ATTR_RO(thread_siblings); -static DEVICE_ATTR_RO(thread_siblings_list); +define_siblings_read_func(thread_siblings, sibling_cpumask); +static BIN_ATTR_RO(thread_siblings, 0); +static BIN_ATTR_RO(thread_siblings_list, 0); -define_siblings_show_func(core_cpus, sibling_cpumask); -static DEVICE_ATTR_RO(core_cpus); -static DEVICE_ATTR_RO(core_cpus_list); +define_siblings_read_func(core_cpus, sibling_cpumask); +static BIN_ATTR_RO(core_cpus, 0); +static BIN_ATTR_RO(core_cpus_list, 0); -define_siblings_show_func(core_siblings, core_cpumask); -static DEVICE_ATTR_RO(core_siblings); -static DEVICE_ATTR_RO(core_siblings_list); +define_siblings_read_func(core_siblings, core_cpumask); +static BIN_ATTR_RO(core_siblings, 0); +static BIN_ATTR_RO(core_siblings_list, 0); -define_siblings_show_func(die_cpus, die_cpumask); -static DEVICE_ATTR_RO(die_cpus); -static DEVICE_ATTR_RO(die_cpus_list); +define_siblings_read_func(die_cpus, die_cpumask); +static BIN_ATTR_RO(die_cpus, 0); +static BIN_ATTR_RO(die_cpus_list, 0); -define_siblings_show_func(package_cpus, core_cpumask); -static DEVICE_ATTR_RO(package_cpus); -static DEVICE_ATTR_RO(package_cpus_list); +define_siblings_read_func(package_cpus, core_cpumask); +static BIN_ATTR_RO(package_cpus, 0); +static BIN_ATTR_RO(package_cpus_list, 0); #ifdef CONFIG_SCHED_BOOK define_id_show_func(book_id); static DEVICE_ATTR_RO(book_id); -define_siblings_show_func(book_siblings, book_cpumask); -static DEVICE_ATTR_RO(book_siblings); -static DEVICE_ATTR_RO(book_siblings_list); +define_siblings_read_func(book_siblings, book_cpumask); +static BIN_ATTR_RO(book_siblings, 0); +static BIN_ATTR_RO(book_siblings_list, 0); #endif #ifdef CONFIG_SCHED_DRAWER define_id_show_func(drawer_id); static DEVICE_ATTR_RO(drawer_id); -define_siblings_show_func(drawer_siblings, drawer_cpumask); -static DEVICE_ATTR_RO(drawer_siblings); -static DEVICE_ATTR_RO(drawer_siblings_list); +define_siblings_read_func(drawer_siblings, drawer_cpumask); +static BIN_ATTR_RO(drawer_siblings, 0); +static BIN_ATTR_RO(drawer_siblings_list, 0); #endif +static struct bin_attribute *bin_attrs[] = { + &bin_attr_core_cpus, + &bin_attr_core_cpus_list, + &bin_attr_thread_siblings, + &bin_attr_thread_siblings_list, + &bin_attr_core_siblings, + &bin_attr_core_siblings_list, + &bin_attr_die_cpus, + &bin_attr_die_cpus_list, + &bin_attr_package_cpus, + &bin_attr_package_cpus_list, +#ifdef CONFIG_SCHED_BOOK + &bin_attr_book_siblings, + &bin_attr_book_siblings_list, +#endif +#ifdef CONFIG_SCHED_DRAWER + &bin_attr_drawer_siblings, + &bin_attr_drawer_siblings_list, +#endif + NULL, +}; + static struct attribute *default_attrs[] = { &dev_attr_physical_package_id.attr, &dev_attr_die_id.attr, &dev_attr_core_id.attr, - &dev_attr_thread_siblings.attr, - &dev_attr_thread_siblings_list.attr, - &dev_attr_core_cpus.attr, - &dev_attr_core_cpus_list.attr, - &dev_attr_core_siblings.attr, - &dev_attr_core_siblings_list.attr, - &dev_attr_die_cpus.attr, - &dev_attr_die_cpus_list.attr, - &dev_attr_package_cpus.attr, - &dev_attr_package_cpus_list.attr, #ifdef CONFIG_SCHED_BOOK &dev_attr_book_id.attr, - &dev_attr_book_siblings.attr, - &dev_attr_book_siblings_list.attr, #endif #ifdef CONFIG_SCHED_DRAWER &dev_attr_drawer_id.attr, - &dev_attr_drawer_siblings.attr, - &dev_attr_drawer_siblings_list.attr, #endif NULL }; static const struct attribute_group topology_attr_group = { .attrs = default_attrs, + .bin_attrs = bin_attrs, .name = "topology" }; diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 70a9324..bc401bd9b 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -219,6 +219,9 @@ extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int extern int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, int nmaskbits); +extern int bitmap_print_to_buf(bool list, char *buf, + const unsigned long *maskp, int nmaskbits, loff_t off, size_t count); + #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index 383684e..e4810b3e 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -928,6 +928,31 @@ cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask) nr_cpu_ids); } +/** + * cpumap_print_to_buf - copies the cpumask into the buffer either + * as comma-separated list of cpus or hex values of cpumask + * @list: indicates whether the cpumap must be list + * @mask: the cpumask to copy + * @buf: the buffer to copy into + * @off: the offset that buffer to copy into + * @count: the count thatbuffer to copy into + * + * the role of cpumap_print_to_buf and cpumap_print_to_pagebuf is + * the same, the difference is that the second parameter of + * bitmap_print_to_buf can be more than one pagesize. + * + * Returns the length of the (null-terminated) @buf string, zero if + * nothing is copied. + */ + +static inline ssize_t +cpumap_print_to_buf(bool list, char *buf, const struct cpumask *mask, + loff_t off, size_t count) +{ + return bitmap_print_to_buf(list, buf, cpumask_bits(mask), + nr_cpu_ids, off, count); +} + #if NR_CPUS <= BITS_PER_LONG #define CPU_MASK_ALL \ (cpumask_t) { { \ diff --git a/lib/bitmap.c b/lib/bitmap.c index 75006c4..5bf89f1 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -460,6 +460,40 @@ int bitmap_parse_user(const char __user *ubuf, EXPORT_SYMBOL(bitmap_parse_user); /** + * bitmap_print_to_buf - convert bitmap to list or hex format ASCII string + * @list: indicates whether the bitmap must be list + * @buf: page aligned buffer into which string is placed + * @maskp: pointer to bitmap to convert + * @nmaskbits: size of bitmap, in bits + * @off: offset in buf + * @count: count that already output + * + * the role of bitmap_print_to_buf and bitmap_print_to_pagebuf is + * the same, the difference is that the second parameter of + * bitmap_print_to_buf can be more than one pagesize. + */ +int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp, + int nmaskbits, loff_t off, size_t count) +{ + int len, size; + void *data; + char *fmt = list ? "%*pbl\n" : "%*pb\n"; + + len = snprintf(NULL, 0, fmt, nmaskbits, maskp); + + data = kvmalloc(len+1, GFP_KERNEL); + if (!data) + return -ENOMEM; + + size = scnprintf(data, len+1, fmt, nmaskbits, maskp); + size = memory_read_from_buffer(buf, count, &off, data, size); + kvfree(data); + + return size; +} +EXPORT_SYMBOL(bitmap_print_to_buf); + +/** * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string * @list: indicates whether the bitmap must be list * @buf: page aligned buffer into which string is placed -- 2.7.4