1 files changed, 36 insertions, 0 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 989af5e55d1b..ec158dd02b3a 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -715,6 +715,40 @@ static const struct file_operations proc_oom_adjust_operations = {
         .write          = oom_adjust_write,
 };
 
+static ssize_t clear_refs_write(struct file *file, const char __user *buf,
+                                size_t count, loff_t *ppos)
+{
+        struct task_struct *task;
+        char buffer[PROC_NUMBUF], *end;
+        struct mm_struct *mm;
+
+        memset(buffer, 0, sizeof(buffer));
+        if (count > sizeof(buffer) - 1)
+                count = sizeof(buffer) - 1;
+        if (copy_from_user(buffer, buf, count))
+                return -EFAULT;
+        if (!simple_strtol(buffer, &end, 0))
+                return -EINVAL;
+        if (*end == '\n')
+                end++;
+        task = get_proc_task(file->f_path.dentry->d_inode);
+        if (!task)
+                return -ESRCH;
+        mm = get_task_mm(task);
+        if (mm) {
+                clear_refs_smap(mm);
+                mmput(mm);
+        }
+        put_task_struct(task);
+        if (end - buffer == 0)
+                return -EIO;
+        return end - buffer;
+}
+
+static struct file_operations proc_clear_refs_operations = {
+        .write          = clear_refs_write,
+};
+
 #ifdef CONFIG_AUDITSYSCALL
 #define TMPBUFLEN 21
 static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
@@ -1851,6 +1885,7 @@ static struct pid_entry tgid_base_stuff[] = {
         REG("mounts",     S_IRUGO, mounts),
         REG("mountstats", S_IRUSR, mountstats),
 #ifdef CONFIG_MMU
+        REG("clear_refs", S_IWUSR, clear_refs),
         REG("smaps",      S_IRUGO, smaps),
 #endif
 #ifdef CONFIG_SECURITY
@@ -2132,6 +2167,7 @@ static struct pid_entry tid_base_stuff[] = {
         LNK("exe",       exe),
         REG("mounts",    S_IRUGO, mounts),
 #ifdef CONFIG_MMU
+        REG("clear_refs", S_IWUSR, clear_refs),
         REG("smaps",     S_IRUGO, smaps),
 #endif
 #ifdef CONFIG_SECURITY