tty: Compute flip buffer ptrs

The char_buf_ptr and flag_buf_ptr values are trivially derived from
the .data field offset; compute values as needed.

Fixes a long-standing type-mismatch with the char and flag ptrs.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 10 insertions, 2 deletions

diff --git a/include/linux/tty.h b/include/linux/tty.h
index 57a70d1d0412..87bbaa31ebf5 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -31,8 +31,6 @@
 
 struct tty_buffer {
         struct tty_buffer *next;
-        char *char_buf_ptr;
-        unsigned char *flag_buf_ptr;
         int used;
         int size;
         int commit;
@@ -41,6 +39,16 @@ struct tty_buffer {
         unsigned long data[0];
 };
 
+static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
+{
+        return ((unsigned char *)b->data) + ofs;
+}
+
+static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
+{
+        return (char *)char_buf_ptr(b, ofs) + b->size;
+}
+
 /*
  * We default to dicing tty buffer allocations to this many characters
  * in order to avoid multiple page allocations. We know the size of