Merge tag 'drm-intel-next-2020-07-15' of git://anongit.freedesktop.org/drm/drm-intel...

[linux-2.6-microblaze.git] / fs / read_write.c

diff --git a/fs/read_write.c b/fs/read_write.c
index bbfa9b1..4fb7978 100644 (file)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -419,28 +419,42 @@ static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, lo
        return ret;
 }
 
-ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
-                  loff_t *pos)
+ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
 {
+       mm_segment_t old_fs = get_fs();
+       ssize_t ret;
+
+       if (WARN_ON_ONCE(!(file->f_mode & FMODE_READ)))
+               return -EINVAL;
+       if (!(file->f_mode & FMODE_CAN_READ))
+               return -EINVAL;
+
+       if (count > MAX_RW_COUNT)
+               count =  MAX_RW_COUNT;
+       set_fs(KERNEL_DS);
        if (file->f_op->read)
-               return file->f_op->read(file, buf, count, pos);
+               ret = file->f_op->read(file, (void __user *)buf, count, pos);
        else if (file->f_op->read_iter)
-               return new_sync_read(file, buf, count, pos);
+               ret = new_sync_read(file, (void __user *)buf, count, pos);
        else
-               return -EINVAL;
+               ret = -EINVAL;
+       set_fs(old_fs);
+       if (ret > 0) {
+               fsnotify_access(file);
+               add_rchar(current, ret);
+       }
+       inc_syscr(current);
+       return ret;
 }
 
 ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
 {
-       mm_segment_t old_fs;
-       ssize_t result;
+       ssize_t ret;
 
-       old_fs = get_fs();
-       set_fs(KERNEL_DS);
-       /* The cast to a user pointer is valid due to the set_fs() */
-       result = vfs_read(file, (void __user *)buf, count, pos);
-       set_fs(old_fs);
-       return result;
+       ret = rw_verify_area(READ, file, pos, count);
+       if (ret)
+               return ret;
+       return __kernel_read(file, buf, count, pos);
 }
 EXPORT_SYMBOL(kernel_read);
 
@@ -456,17 +470,22 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
                return -EFAULT;
 
        ret = rw_verify_area(READ, file, pos, count);
-       if (!ret) {
-               if (count > MAX_RW_COUNT)
-                       count =  MAX_RW_COUNT;
-               ret = __vfs_read(file, buf, count, pos);
-               if (ret > 0) {
-                       fsnotify_access(file);
-                       add_rchar(current, ret);
-               }
-               inc_syscr(current);
-       }
+       if (ret)
+               return ret;
+       if (count > MAX_RW_COUNT)
+               count =  MAX_RW_COUNT;
 
+       if (file->f_op->read)
+               ret = file->f_op->read(file, buf, count, pos);
+       else if (file->f_op->read_iter)
+               ret = new_sync_read(file, buf, count, pos);
+       else
+               ret = -EINVAL;
+       if (ret > 0) {
+               fsnotify_access(file);
+               add_rchar(current, ret);
+       }
+       inc_syscr(current);
        return ret;
 }
 
@@ -488,23 +507,15 @@ static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t
        return ret;
 }
 
-static ssize_t __vfs_write(struct file *file, const char __user *p,
-                          size_t count, loff_t *pos)
-{
-       if (file->f_op->write)
-               return file->f_op->write(file, p, count, pos);
-       else if (file->f_op->write_iter)
-               return new_sync_write(file, p, count, pos);
-       else
-               return -EINVAL;
-}
-
+/* caller is responsible for file_start_write/file_end_write */
 ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos)
 {
        mm_segment_t old_fs;
        const char __user *p;
        ssize_t ret;
 
+       if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE)))
+               return -EBADF;
        if (!(file->f_mode & FMODE_CAN_WRITE))
                return -EINVAL;
 
@@ -513,7 +524,12 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t
        p = (__force const char __user *)buf;
        if (count > MAX_RW_COUNT)
                count =  MAX_RW_COUNT;
-       ret = __vfs_write(file, p, count, pos);
+       if (file->f_op->write)
+               ret = file->f_op->write(file, p, count, pos);
+       else if (file->f_op->write_iter)
+               ret = new_sync_write(file, p, count, pos);
+       else
+               ret = -EINVAL;
        set_fs(old_fs);
        if (ret > 0) {
                fsnotify_modify(file);
@@ -522,21 +538,20 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t
        inc_syscw(current);
        return ret;
 }
-EXPORT_SYMBOL(__kernel_write);
 
 ssize_t kernel_write(struct file *file, const void *buf, size_t count,
                            loff_t *pos)
 {
-       mm_segment_t old_fs;
-       ssize_t res;
+       ssize_t ret;
 
-       old_fs = get_fs();
-       set_fs(KERNEL_DS);
-       /* The cast to a user pointer is valid due to the set_fs() */
-       res = vfs_write(file, (__force const char __user *)buf, count, pos);
-       set_fs(old_fs);
+       ret = rw_verify_area(WRITE, file, pos, count);
+       if (ret)
+               return ret;
 
-       return res;
+       file_start_write(file);
+       ret =  __kernel_write(file, buf, count, pos);
+       file_end_write(file);
+       return ret;
 }
 EXPORT_SYMBOL(kernel_write);
 
@@ -552,19 +567,23 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_
                return -EFAULT;
 
        ret = rw_verify_area(WRITE, file, pos, count);
-       if (!ret) {
-               if (count > MAX_RW_COUNT)
-                       count =  MAX_RW_COUNT;
-               file_start_write(file);
-               ret = __vfs_write(file, buf, count, pos);
-               if (ret > 0) {
-                       fsnotify_modify(file);
-                       add_wchar(current, ret);
-               }
-               inc_syscw(current);
-               file_end_write(file);
+       if (ret)
+               return ret;
+       if (count > MAX_RW_COUNT)
+               count =  MAX_RW_COUNT;
+       file_start_write(file);
+       if (file->f_op->write)
+               ret = file->f_op->write(file, buf, count, pos);
+       else if (file->f_op->write_iter)
+               ret = new_sync_write(file, buf, count, pos);
+       else
+               ret = -EINVAL;
+       if (ret > 0) {
+               fsnotify_modify(file);
+               add_wchar(current, ret);
        }
-
+       inc_syscw(current);
+       file_end_write(file);
        return ret;
 }