From: Tian Tao <tiantao6@hisilicon.com>
To: <gregkh@linuxfoundation.org>, <linux-kernel@vger.kernel.org>,
<akpm@linux-foundation.org>, <song.bao.hua@hisilicon.com>
Cc: Tian Tao <tiantao6@hisilicon.com>,
"Rafael J. Wysocki" <rafael@kernel.org>
Subject: [PATCH 2/2] drivers/base/node.c: use bin_attribute to avoid buff overflow
Date: Tue, 1 Jun 2021 10:56:50 +0800 [thread overview]
Message-ID: <1622516210-10886-3-git-send-email-tiantao6@hisilicon.com> (raw)
In-Reply-To: <1622516210-10886-1-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 | 49 +++++++++++++++++++++++++++++++------------------
1 file changed, 31 insertions(+), 18 deletions(-)
diff --git a/drivers/base/node.c b/drivers/base/node.c
index f449dbb..a19be64 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -27,42 +27,42 @@ 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 kobject *kobj, bool list,
+ char *buf, loff_t off, size_t count)
{
ssize_t n;
cpumask_var_t mask;
+ struct device *dev = kobj_to_dev(kobj);
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);
+ return node_read_cpumap(kobj, 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);
+ return node_read_cpumap(kobj, 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 +557,28 @@ 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:[~2021-06-01 2:57 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-01 2:56 [PATCH 0/2] use bin_attribute to avoid buff overflow Tian Tao
2021-06-01 2:56 ` [PATCH 1/2] topology: " Tian Tao
2021-06-01 4:58 ` Greg KH
2021-06-01 7:04 ` Song Bao Hua (Barry Song)
2021-06-01 7:13 ` Greg KH
2021-06-02 6:14 ` tiantao (H)
2021-06-02 6:18 ` Greg KH
2021-06-02 6:28 ` tiantao (H)
2021-06-02 8:48 ` Andy Shevchenko
2021-06-02 9:00 ` tiantao (H)
2021-06-02 9:06 ` Greg KH
2021-06-02 9:20 ` Song Bao Hua (Barry Song)
2021-06-02 9:35 ` Greg KH
2021-06-01 2:56 ` Tian Tao [this message]
2021-06-01 5:01 ` [PATCH 2/2] drivers/base/node.c: " Greg KH
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