diff options
| -rw-r--r-- | drivers/char/mem.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c index aaa9c24d4c1..c6b2fbc5ed4 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -154,6 +154,8 @@ static ssize_t read_mem(struct file * file, char __user * buf, #endif while (count > 0) { + unsigned long remaining; + sz = size_inside_page(p, count); if (!range_is_allowed(p >> PAGE_SHIFT, count)) @@ -168,12 +170,10 @@ static ssize_t read_mem(struct file * file, char __user * buf, if (!ptr) return -EFAULT; - if (copy_to_user(buf, ptr, sz)) { - unxlate_dev_mem_ptr(p, ptr); - return -EFAULT; - } - + remaining = copy_to_user(buf, ptr, sz); unxlate_dev_mem_ptr(p, ptr); + if (remaining) + return -EFAULT; buf += sz; p += sz; @@ -231,16 +231,14 @@ static ssize_t write_mem(struct file * file, const char __user * buf, } copied = copy_from_user(ptr, buf, sz); + unxlate_dev_mem_ptr(p, ptr); if (copied) { written += sz - copied; - unxlate_dev_mem_ptr(p, ptr); if (written) break; return -EFAULT; } - unxlate_dev_mem_ptr(p, ptr); - buf += sz; p += sz; count -= sz; |