From: Tian Tao <tiantao6@hisilicon.com>
To: <andriy.shevchenko@linux.intel.com>, <gregkh@linuxfoundation.org>,
<rafael@kernel.org>, <akpm@linux-foundation.org>
Cc: <linux-kernel@vger.kernel.org>, <jonathan.cameron@huawei.com>,
<song.bao.hua@hisilicon.com>, Tian Tao <tiantao6@hisilicon.com>
Subject: [PATCH v3 3/3] drivers/base/node.c: use bin_attribute to avoid buff overflow
Date: Thu, 3 Jun 2021 17:22:42 +0800 [thread overview]
Message-ID: <1622712162-7028-4-git-send-email-tiantao6@hisilicon.com> (raw)
In-Reply-To: <1622712162-7028-1-git-send-email-tiantao6@hisilicon.com>
Reading sys/devices/system/cpu/cpuX/nodeX/ returns cpumap and cpulist.
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.
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
---
drivers/base/node.c | 52 ++++++++++++++++++++++++++++++++++------------------
1 file changed, 34 insertions(+), 18 deletions(-)
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 4cef82c..537d046 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -27,42 +27,45 @@ static struct bus_type node_subsys = {
};
-static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf)
+static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf,
+ loff_t off, size_t count)
{
ssize_t n;
cpumask_var_t mask;
struct node *node_dev = to_node(dev);
- /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
- BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));
-
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
return 0;
cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
- n = cpumap_print_to_pagebuf(list, buf, mask);
+ n = cpumap_print_to_buf(list, buf, mask, off, count);
free_cpumask_var(mask);
return n;
}
-static inline ssize_t cpumap_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
+static inline ssize_t cpumap_read(struct file *file, struct kobject *kobj,
+ struct bin_attribute *attr, char *buf,
+ loff_t off, size_t count)
{
- return node_read_cpumap(dev, false, buf);
+ struct device *dev = kobj_to_dev(kobj);
+
+ return node_read_cpumap(dev, false, buf, off, count);
}
-static DEVICE_ATTR_RO(cpumap);
-static inline ssize_t cpulist_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
+static BIN_ATTR_RO(cpumap, 0);
+
+static inline ssize_t cpulist_read(struct file *file, struct kobject *kobj,
+ struct bin_attribute *attr, char *buf,
+ loff_t off, size_t count)
{
- return node_read_cpumap(dev, true, buf);
+ struct device *dev = kobj_to_dev(kobj);
+
+ return node_read_cpumap(dev, true, buf, off, count);
}
-static DEVICE_ATTR_RO(cpulist);
+static BIN_ATTR_RO(cpulist, 0);
/**
* struct node_access_nodes - Access class device to hold user visible
@@ -557,15 +560,28 @@ static ssize_t node_read_distance(struct device *dev,
static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
static struct attribute *node_dev_attrs[] = {
- &dev_attr_cpumap.attr,
- &dev_attr_cpulist.attr,
&dev_attr_meminfo.attr,
&dev_attr_numastat.attr,
&dev_attr_distance.attr,
&dev_attr_vmstat.attr,
NULL
};
-ATTRIBUTE_GROUPS(node_dev);
+
+static struct bin_attribute *node_dev_bin_attrs[] = {
+ &bin_attr_cpumap,
+ &bin_attr_cpulist,
+ NULL
+};
+
+static const struct attribute_group node_dev_group = {
+ .attrs = node_dev_attrs,
+ .bin_attrs = node_dev_bin_attrs
+};
+
+static const struct attribute_group *node_dev_groups[] = {
+ &node_dev_group,
+ NULL
+};
#ifdef CONFIG_HUGETLBFS
/*
--
2.7.4
next prev parent reply other threads:[~2021-06-03 9:23 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-03 9:22 [PATCH v3 0/3] use bin_attribute to avoid buff overflow Tian Tao
2021-06-03 9:22 ` [PATCH v3 1/3] lib: bitmap: introduce bitmap_print_to_buf Tian Tao
2021-06-03 9:50 ` Andy Shevchenko
2021-06-03 10:33 ` tiantao (H)
2021-06-03 10:49 ` Greg KH
[not found] ` <0a43ca2a-7563-0bd6-fd1f-3fef208d71ef@huawei.com>
2021-06-03 11:37 ` Greg KH
2021-06-03 11:38 ` Greg KH
2021-06-03 11:11 ` Andy Shevchenko
2021-06-03 12:39 ` Jonathan Cameron
2021-06-03 13:00 ` Andy Shevchenko
2021-06-03 9:22 ` [PATCH v3 2/3] topology: use bin_attribute to avoid buff overflow Tian Tao
2021-06-03 9:22 ` Tian Tao [this message]
2021-06-03 9:53 ` [PATCH v3 3/3] drivers/base/node.c: " Andy Shevchenko
2021-06-03 10:31 ` tiantao (H)
2021-06-03 11:09 ` Andy Shevchenko
2021-06-03 9:49 ` [PATCH v3 0/3] " Jonathan Cameron
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