[PATCH v2 2/8] Input/joystick/analog: Convert from seq_buf -> printbuf

Kent Overstreet
2022-04-21T23:48:58Z

seq_buf is being deprecated, this converts to printbuf which is similar
but heap allocates the string buffer.

This means we have to consider memory allocation context & failure: Here
we're in device initialization so GFP_KERNEL should be fine, and also as
we're in device initialization returning -ENOMEM is fine.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
---
drivers/input/joystick/analog.c | 37 ++++++++++++++++++++-------------
1 file changed, 23 insertions(+), 14 deletions(-)

diff --git a/drivers/input/joystick/analog.c b/drivers/input/joystick/analog.c
index 3088c5b829..72e1e30d19 100644
--- a/drivers/input/joystick/analog.c
+++ b/drivers/input/joystick/analog.c
@@ -19,7 +19,7 @@
#include <linux/input.h>
#include <linux/gameport.h>
#include <linux/jiffies.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include <linux/timex.h>
#include <linux/timekeeping.h>

@@ -337,26 +337,32 @@ static void analog_calibrate_timer(struct analog_port *port)
* analog_name() constructs a name for an analog joystick.
*/

-static void analog_name(struct analog *analog)
+static int analog_name(struct analog *analog)
{
- struct seq_buf s;
+ struct printbuf buf = PRINTBUF;
+ int ret = 0;

- seq_buf_init(&s, analog->name, sizeof(analog->name));
- seq_buf_printf(&s, "Analog %d-axis %d-button",
- hweight8(analog->mask & ANALOG_AXES_STD),
- hweight8(analog->mask & ANALOG_BTNS_STD) + !!(analog->mask & ANALOG_BTNS_CHF) * 2 +
- hweight16(analog->mask & ANALOG_BTNS_GAMEPAD) + !!(analog->mask & ANALOG_HBTN_CHF) * 4);
+ pr_buf(&buf, "Analog %d-axis %d-button",
+ hweight8(analog->mask & ANALOG_AXES_STD),
+ hweight8(analog->mask & ANALOG_BTNS_STD) + !!(analog->mask & ANALOG_BTNS_CHF) * 2 +
+ hweight16(analog->mask & ANALOG_BTNS_GAMEPAD) + !!(analog->mask & ANALOG_HBTN_CHF) * 4);

if (analog->mask & ANALOG_HATS_ALL)
- seq_buf_printf(&s, " %d-hat",
- hweight16(analog->mask & ANALOG_HATS_ALL));
+ pr_buf(&buf, " %d-hat",
+ hweight16(analog->mask & ANALOG_HATS_ALL));

if (analog->mask & ANALOG_HAT_FCS)
- seq_buf_printf(&s, " FCS");
+ pr_buf(&buf, " FCS");
if (analog->mask & ANALOG_ANY_CHF)
- seq_buf_printf(&s, (analog->mask & ANALOG_SAITEK) ? " Saitek" : " CHF");
+ pr_buf(&buf, (analog->mask & ANALOG_SAITEK) ? " Saitek" : " CHF");

- seq_buf_printf(&s, (analog->mask & ANALOG_GAMEPAD) ? " gamepad" : " joystick");
+ pr_buf(&buf, (analog->mask & ANALOG_GAMEPAD) ? " gamepad" : " joystick");
+
+ ret = buf.allocation_failure ? -ENOMEM : 0;
+ if (!ret)
+ strlcpy(analog->name, buf.buf, sizeof(analog->name));
+ printbuf_exit(&buf);
+ return ret;
}

/*
@@ -369,7 +375,10 @@ static int analog_init_device(struct analog_port *port, struct analog *analog, i
int i, j, t, v, w, x, y, z;
int error;

- analog_name(analog);
+ error = analog_name(analog);
+ if (error)
+ return error;
+
snprintf(analog->phys, sizeof(analog->phys),
"%s/input%d", port->gameport->phys, index);
analog->buttons = (analog->mask & ANALOG_GAMEPAD) ? analog_pad_btn : analog_joy_btn;
--
2.35.2