tty: tty_buffer: switch data type to u8

There is no reason to have tty_buffer::data typed as unsigned long.
Switch to u8, but preserve the ulong alignment using __aligned.

This allows for the cast removal from char_buf_ptr(). And for use of
struct_size() in the allocation in tty_buffer_alloc() -- in the next
patch.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230816105530.3335-2-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/tty_buffer.h b/include/linux/tty_buffer.h
index e45cba8..31125e3 100644 (file)
--- a/include/linux/tty_buffer.h
+++ b/include/linux/tty_buffer.h
@@ -19,12 +19,12 @@ struct tty_buffer {
        unsigned int read;
        bool flags;
        /* Data points here */
-       unsigned long data[];
+       u8 data[] __aligned(sizeof(unsigned long));
 };
 
 static inline u8 *char_buf_ptr(struct tty_buffer *b, unsigned int ofs)
 {
-       return ((u8 *)b->data) + ofs;
+       return b->data + ofs;
 }
 
 static inline u8 *flag_buf_ptr(struct tty_buffer *b, unsigned int ofs)