[PATCH 05/10] tty: tty_buffer: switch insert functions to size_t

Jiri Slaby (SUSE)
2023-08-16T10:56:40Z

All the functions accept size_t as a size argument. They finally return
the same size (or less). It is quite unexpected that they return a
signed value and can confuse users to check for negative values.

Instead, return the same size_t as accepted to make clear we return
values >= 0, where zero in fact means failure.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
---
drivers/tty/tty_buffer.c | 12 ++++++------
include/linux/tty_flip.h | 24 ++++++++++++------------
2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index c101b4ab737e..598891e53031 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -303,16 +303,16 @@ int tty_buffer_request_room(struct tty_port *port, size_t size)
}
EXPORT_SYMBOL_GPL(tty_buffer_request_room);

-int __tty_insert_flip_string_flags(struct tty_port *port, const u8 *chars,
- const u8 *flags, bool mutable_flags,
- size_t size)
+size_t __tty_insert_flip_string_flags(struct tty_port *port, const u8 *chars,
+ const u8 *flags, bool mutable_flags,
+ size_t size)
{
bool need_flags = mutable_flags || flags[0] != TTY_NORMAL;
- int copied = 0;
+ size_t copied = 0;

do {
- int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
- int space = __tty_buffer_request_room(port, goal, need_flags);
+ size_t goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
+ size_t space = __tty_buffer_request_room(port, goal, need_flags);
struct tty_buffer *tb = port->buf.tail;

if (unlikely(space == 0))
diff --git a/include/linux/tty_flip.h b/include/linux/tty_flip.h
index 8b781f709605..569747364ae5 100644
--- a/include/linux/tty_flip.h
+++ b/include/linux/tty_flip.h
@@ -10,9 +10,9 @@ struct tty_ldisc;
int tty_buffer_set_limit(struct tty_port *port, int limit);
unsigned int tty_buffer_space_avail(struct tty_port *port);
int tty_buffer_request_room(struct tty_port *port, size_t size);
-int __tty_insert_flip_string_flags(struct tty_port *port, const u8 *chars,
- const u8 *flags, bool mutable_flags,
- size_t size);
+size_t __tty_insert_flip_string_flags(struct tty_port *port, const u8 *chars,
+ const u8 *flags, bool mutable_flags,
+ size_t size);
int tty_prepare_flip_string(struct tty_port *port, u8 **chars, size_t size);
void tty_flip_buffer_push(struct tty_port *port);
int __tty_insert_flip_char(struct tty_port *port, u8 ch, u8 flag);
@@ -29,9 +29,9 @@ int __tty_insert_flip_char(struct tty_port *port, u8 ch, u8 flag);
*
* Returns: the number added.
*/
-static inline int tty_insert_flip_string_fixed_flag(struct tty_port *port,
- const u8 *chars, u8 flag,
- size_t size)
+static inline size_t tty_insert_flip_string_fixed_flag(struct tty_port *port,
+ const u8 *chars, u8 flag,
+ size_t size)
{
return __tty_insert_flip_string_flags(port, chars, &flag, false, size);
}
@@ -48,15 +48,15 @@ static inline int tty_insert_flip_string_fixed_flag(struct tty_port *port,
*
* Returns: the number added.
*/
-static inline int tty_insert_flip_string_flags(struct tty_port *port,
- const u8 *chars, const u8 *flags,
- size_t size)
+static inline size_t tty_insert_flip_string_flags(struct tty_port *port,
+ const u8 *chars,
+ const u8 *flags, size_t size)
{
return __tty_insert_flip_string_flags(port, chars, flags, true, size);
}

-static inline int tty_insert_flip_char(struct tty_port *port, u8 ch, u8 flag)
+static inline size_t tty_insert_flip_char(struct tty_port *port, u8 ch, u8 flag)
{
struct tty_buffer *tb = port->buf.tail;
int change;
@@ -71,8 +71,8 @@ static inline int tty_insert_flip_char(struct tty_port *port, u8 ch, u8 flag)
return __tty_insert_flip_char(port, ch, flag);
}

-static inline int tty_insert_flip_string(struct tty_port *port,
- const u8 *chars, size_t size)
+static inline size_t tty_insert_flip_string(struct tty_port *port,
+ const u8 *chars, size_t size)
{
return tty_insert_flip_string_fixed_flag(port, chars, TTY_NORMAL, size);
}
--
2.41.0