procfs: use simple_read_from_buffer()

Cleanup using simple_read_from_buffer() in procfs.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 28 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index ff9c131e6b30..3c41149dea88 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -660,7 +660,6 @@ static ssize_t oom_adjust_read(struct file *file, char __user *buf,
         char buffer[PROC_NUMBUF];
         size_t len;
         int oom_adjust;
-        loff_t __ppos = *ppos;
 
         if (!task)
                 return -ESRCH;
@@ -668,14 +667,8 @@ static ssize_t oom_adjust_read(struct file *file, char __user *buf,
         put_task_struct(task);
 
         len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
-        if (__ppos >= len)
-                return 0;
-        if (count > len-__ppos)
-                count = len-__ppos;
-        if (copy_to_user(buf, buffer + __ppos, count))
-                return -EFAULT;
-        *ppos = __ppos + count;
-        return count;
+
+        return simple_read_from_buffer(buf, count, ppos, buffer, len);
 }
 
 static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
@@ -823,7 +816,6 @@ static ssize_t seccomp_read(struct file *file, char __user *buf,
 {
         struct task_struct *tsk = get_proc_task(file->f_dentry->d_inode);
         char __buf[20];
-        loff_t __ppos = *ppos;
         size_t len;
 
         if (!tsk)
@@ -831,14 +823,8 @@ static ssize_t seccomp_read(struct file *file, char __user *buf,
         /* no need to print the trailing zero, so use only len */
         len = sprintf(__buf, "%u\n", tsk->seccomp.mode);
         put_task_struct(tsk);
-        if (__ppos >= len)
-                return 0;
-        if (count > len - __ppos)
-                count = len - __ppos;
-        if (copy_to_user(buf, __buf + __ppos, count))
-                return -EFAULT;
-        *ppos = __ppos + count;
-        return count;
+
+        return simple_read_from_buffer(buf, count, ppos, __buf, len);
 }
 
 static ssize_t seccomp_write(struct file *file, const char __user *buf,
@@ -897,7 +883,6 @@ static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
         char buffer[PROC_NUMBUF];
         size_t len;
         int make_it_fail;
-        loff_t __ppos = *ppos;
 
         if (!task)
                 return -ESRCH;
@@ -905,14 +890,8 @@ static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
         put_task_struct(task);
 
         len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
-        if (__ppos >= len)
-                return 0;
-        if (count > len-__ppos)
-                count = len-__ppos;
-        if (copy_to_user(buf, buffer + __ppos, count))
-                return -EFAULT;
-        *ppos = __ppos + count;
-        return count;
+
+        return simple_read_from_buffer(buf, count, ppos, buffer, len);
 }
 
 static ssize_t proc_fault_inject_write(struct file * file,
@@ -975,7 +954,7 @@ static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
 
         if (!tmp)
                 return -ENOMEM;
-                
+
         inode = dentry->d_inode;
         path = d_path(dentry, mnt, tmp, PAGE_SIZE);
         len = PTR_ERR(path);