[PATCH] use simple_read_from_buffer in selinuxfs
From: Chris Wright
Date: Sat Aug 14 2004 - 18:17:48 EST
Use simple_read_from_buffer. This also eliminates page allocation
for the sprintf buffer. Switch to get_zeroed_page instead of
open-coding it. Viro had ack'd this earlier. Still applies w/
the transaction update.
Signed-off-by: Chris Wright <chrisw@xxxxxxxx>
===== security/selinux/selinuxfs.c 1.12 vs edited =====
--- 1.12/security/selinux/selinuxfs.c 2004-06-03 18:47:11 -07:00
+++ edited/security/selinux/selinuxfs.c 2004-08-06 17:44:52 -07:00
@@ -68,40 +68,15 @@
SEL_DISABLE /* disable SELinux until next reboot */
};
+#define TMPBUFLEN 12
static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
- char *page;
+ char tmpbuf[TMPBUFLEN];
ssize_t length;
- ssize_t end;
-
- if (count < 0 || count > PAGE_SIZE)
- return -EINVAL;
- if (!(page = (char*)__get_free_page(GFP_KERNEL)))
- return -ENOMEM;
- memset(page, 0, PAGE_SIZE);
-
- length = scnprintf(page, PAGE_SIZE, "%d", selinux_enforcing);
- if (length < 0) {
- free_page((unsigned long)page);
- return length;
- }
- if (*ppos >= length) {
- free_page((unsigned long)page);
- return 0;
- }
- if (count + *ppos > length)
- count = length - *ppos;
- end = count + *ppos;
- if (copy_to_user(buf, (char *) page + *ppos, count)) {
- count = -EFAULT;
- goto out;
- }
- *ppos = end;
-out:
- free_page((unsigned long)page);
- return count;
+ length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
+ return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
@@ -119,10 +94,9 @@
/* No partial writes. */
return -EINVAL;
}
- page = (char*)__get_free_page(GFP_KERNEL);
+ page = (char*)get_zeroed_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
- memset(page, 0, PAGE_SIZE);
length = -EFAULT;
if (copy_from_user(page, buf, count))
goto out;
@@ -170,10 +144,9 @@
/* No partial writes. */
return -EINVAL;
}
- page = (char*)__get_free_page(GFP_KERNEL);
+ page = (char*)get_zeroed_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
- memset(page, 0, PAGE_SIZE);
length = -EFAULT;
if (copy_from_user(page, buf, count))
goto out;
@@ -204,37 +177,11 @@
static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
- char *page;
+ char tmpbuf[TMPBUFLEN];
ssize_t length;
- ssize_t end;
-
- if (count < 0 || count > PAGE_SIZE)
- return -EINVAL;
- if (!(page = (char*)__get_free_page(GFP_KERNEL)))
- return -ENOMEM;
- memset(page, 0, PAGE_SIZE);
- length = scnprintf(page, PAGE_SIZE, "%u", POLICYDB_VERSION_MAX);
- if (length < 0) {
- free_page((unsigned long)page);
- return length;
- }
-
- if (*ppos >= length) {
- free_page((unsigned long)page);
- return 0;
- }
- if (count + *ppos > length)
- count = length - *ppos;
- end = count + *ppos;
- if (copy_to_user(buf, (char *) page + *ppos, count)) {
- count = -EFAULT;
- goto out;
- }
- *ppos = end;
-out:
- free_page((unsigned long)page);
- return count;
+ length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
+ return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
static struct file_operations sel_policyvers_ops = {
@@ -247,37 +194,11 @@
static ssize_t sel_read_mls(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
- char *page;
+ char tmpbuf[TMPBUFLEN];
ssize_t length;
- ssize_t end;
-
- if (count < 0 || count > PAGE_SIZE)
- return -EINVAL;
- if (!(page = (char*)__get_free_page(GFP_KERNEL)))
- return -ENOMEM;
- memset(page, 0, PAGE_SIZE);
-
- length = scnprintf(page, PAGE_SIZE, "%d", selinux_mls_enabled);
- if (length < 0) {
- free_page((unsigned long)page);
- return length;
- }
- if (*ppos >= length) {
- free_page((unsigned long)page);
- return 0;
- }
- if (count + *ppos > length)
- count = length - *ppos;
- end = count + *ppos;
- if (copy_to_user(buf, (char *) page + *ppos, count)) {
- count = -EFAULT;
- goto out;
- }
- *ppos = end;
-out:
- free_page((unsigned long)page);
- return count;
+ length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_mls_enabled);
+ return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
static struct file_operations sel_mls_ops = {
@@ -352,10 +273,9 @@
/* No partial writes. */
return -EINVAL;
}
- page = (char*)__get_free_page(GFP_KERNEL);
+ page = (char*)get_zeroed_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
- memset(page, 0, PAGE_SIZE);
length = -EFAULT;
if (copy_from_user(page, buf, count))
goto out;
@@ -766,11 +679,10 @@
ret = -EINVAL;
goto out;
}
- if (!(page = (char*)__get_free_page(GFP_KERNEL))) {
+ if (!(page = (char*)get_zeroed_page(GFP_KERNEL))) {
ret = -ENOMEM;
goto out;
}
- memset(page, 0, PAGE_SIZE);
inode = filep->f_dentry->d_inode;
cur_enforcing = security_get_bool_value(inode->i_ino - BOOL_INO_OFFSET);
@@ -832,12 +744,11 @@
/* No partial writes. */
goto out;
}
- page = (char*)__get_free_page(GFP_KERNEL);
+ page = (char*)get_zeroed_page(GFP_KERNEL);
if (!page) {
length = -ENOMEM;
goto out;
}
- memset(page, 0, PAGE_SIZE);
if (copy_from_user(page, buf, count))
goto out;
@@ -891,14 +802,12 @@
/* No partial writes. */
goto out;
}
- page = (char*)__get_free_page(GFP_KERNEL);
+ page = (char*)get_zeroed_page(GFP_KERNEL);
if (!page) {
length = -ENOMEM;
goto out;
}
- memset(page, 0, PAGE_SIZE);
-
if (copy_from_user(page, buf, count))
goto out;
@@ -984,9 +893,8 @@
sel_remove_bools(dir);
- if (!(page = (char*)__get_free_page(GFP_KERNEL)))
+ if (!(page = (char*)get_zeroed_page(GFP_KERNEL)))
return -ENOMEM;
- memset(page, 0, PAGE_SIZE);
ret = security_get_bools(&num, &names, &values);
if (ret != 0)
-
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