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-rw-r--r--fs/proc/generic.c32
-rw-r--r--fs/proc/proc_devtree.c2
-rw-r--r--include/linux/proc_fs.h3
3 files changed, 34 insertions, 3 deletions
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 20e5c4509a43..47b7a20d45eb 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -19,6 +19,7 @@
#include <linux/idr.h>
#include <linux/namei.h>
#include <linux/bitops.h>
+#include <linux/spinlock.h>
#include <asm/uaccess.h>
#include "internal.h"
@@ -29,6 +30,8 @@ static ssize_t proc_file_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos);
static loff_t proc_file_lseek(struct file *, loff_t, int);
+DEFINE_SPINLOCK(proc_subdir_lock);
+
int proc_match(int len, const char *name, struct proc_dir_entry *de)
{
if (de->namelen != len)
@@ -277,7 +280,9 @@ static int xlate_proc_name(const char *name,
const char *cp = name, *next;
struct proc_dir_entry *de;
int len;
+ int rtn = 0;
+ spin_lock(&proc_subdir_lock);
de = &proc_root;
while (1) {
next = strchr(cp, '/');
@@ -289,13 +294,17 @@ static int xlate_proc_name(const char *name,
if (proc_match(len, cp, de))
break;
}
- if (!de)
- return -ENOENT;
+ if (!de) {
+ rtn = -ENOENT;
+ goto out;
+ }
cp += len + 1;
}
*residual = cp;
*ret = de;
- return 0;
+out:
+ spin_unlock(&proc_subdir_lock);
+ return rtn;
}
static DEFINE_IDR(proc_inum_idr);
@@ -380,6 +389,7 @@ struct dentry *proc_lookup(struct inode * dir, struct dentry *dentry, struct nam
int error = -ENOENT;
lock_kernel();
+ spin_lock(&proc_subdir_lock);
de = PDE(dir);
if (de) {
for (de = de->subdir; de ; de = de->next) {
@@ -388,12 +398,15 @@ struct dentry *proc_lookup(struct inode * dir, struct dentry *dentry, struct nam
if (!memcmp(dentry->d_name.name, de->name, de->namelen)) {
unsigned int ino = de->low_ino;
+ spin_unlock(&proc_subdir_lock);
error = -EINVAL;
inode = proc_get_inode(dir->i_sb, ino, de);
+ spin_lock(&proc_subdir_lock);
break;
}
}
}
+ spin_unlock(&proc_subdir_lock);
unlock_kernel();
if (inode) {
@@ -447,11 +460,13 @@ int proc_readdir(struct file * filp,
filp->f_pos++;
/* fall through */
default:
+ spin_lock(&proc_subdir_lock);
de = de->subdir;
i -= 2;
for (;;) {
if (!de) {
ret = 1;
+ spin_unlock(&proc_subdir_lock);
goto out;
}
if (!i)
@@ -461,12 +476,16 @@ int proc_readdir(struct file * filp,
}
do {
+ /* filldir passes info to user space */
+ spin_unlock(&proc_subdir_lock);
if (filldir(dirent, de->name, de->namelen, filp->f_pos,
de->low_ino, de->mode >> 12) < 0)
goto out;
+ spin_lock(&proc_subdir_lock);
filp->f_pos++;
de = de->next;
} while (de);
+ spin_unlock(&proc_subdir_lock);
}
ret = 1;
out: unlock_kernel();
@@ -500,9 +519,13 @@ static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp
if (i == 0)
return -EAGAIN;
dp->low_ino = i;
+
+ spin_lock(&proc_subdir_lock);
dp->next = dir->subdir;
dp->parent = dir;
dir->subdir = dp;
+ spin_unlock(&proc_subdir_lock);
+
if (S_ISDIR(dp->mode)) {
if (dp->proc_iops == NULL) {
dp->proc_fops = &proc_dir_operations;
@@ -694,6 +717,8 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
if (!parent && xlate_proc_name(name, &parent, &fn) != 0)
goto out;
len = strlen(fn);
+
+ spin_lock(&proc_subdir_lock);
for (p = &parent->subdir; *p; p=&(*p)->next ) {
if (!proc_match(len, fn, *p))
continue;
@@ -714,6 +739,7 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
}
break;
}
+ spin_unlock(&proc_subdir_lock);
out:
return;
}
diff --git a/fs/proc/proc_devtree.c b/fs/proc/proc_devtree.c
index 9bdd077d6f55..596b4b4f1cc8 100644
--- a/fs/proc/proc_devtree.c
+++ b/fs/proc/proc_devtree.c
@@ -136,9 +136,11 @@ void proc_device_tree_add_node(struct device_node *np,
* properties are quite unimportant for us though, thus we
* simply "skip" them here, but we do have to check.
*/
+ spin_lock(&proc_subdir_lock);
for (ent = de->subdir; ent != NULL; ent = ent->next)
if (!strcmp(ent->name, pp->name))
break;
+ spin_unlock(&proc_subdir_lock);
if (ent != NULL) {
printk(KERN_WARNING "device-tree: property \"%s\" name"
" conflicts with node in %s\n", pp->name,
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index aa6322d45198..6b12b0f661b4 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -4,6 +4,7 @@
#include <linux/config.h>
#include <linux/slab.h>
#include <linux/fs.h>
+#include <linux/spinlock.h>
#include <asm/atomic.h>
/*
@@ -92,6 +93,8 @@ extern struct proc_dir_entry *proc_bus;
extern struct proc_dir_entry *proc_root_driver;
extern struct proc_dir_entry *proc_root_kcore;
+extern spinlock_t proc_subdir_lock;
+
extern void proc_root_init(void);
extern void proc_misc_init(void);