* [PATCH] [RESEND] [v2] Input: analog - fix invalid snprintf() call
@ 2021-09-27 10:14 Arnd Bergmann
2021-10-05 20:28 ` Dmitry Torokhov
0 siblings, 1 reply; 2+ messages in thread
From: Arnd Bergmann @ 2021-09-27 10:14 UTC (permalink / raw)
To: Dmitry Torokhov
Cc: Arnd Bergmann, Rasmus Villemoes, Randy Dunlap, Zhang Qilong,
Geert Uytterhoeven, Guenter Roeck, linux-input, linux-kernel
From: Arnd Bergmann <arnd@arndb.de>
Overlapping input and output arguments to snprintf() are
undefined behavior in C99:
drivers/input/joystick/analog.c: In function 'analog_name':
drivers/input/joystick/analog.c:428:3: error: 'snprintf' argument 4 overlaps destination object 'analog' [-Werror=restrict]
428 | snprintf(analog->name, sizeof(analog->name), "%s %d-hat",
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
429 | analog->name, hweight16(analog->mask & ANALOG_HATS_ALL));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/input/joystick/analog.c:420:40: note: destination object referenced by 'restrict'-qualified argument 1 was declared here
420 | static void analog_name(struct analog *analog)
| ~~~~~~~~~~~~~~~^~~~~~
Change this function to use the simpler seq_buf interface instead.
Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Link: https://lore.kernel.org/all/20210323131456.2600132-1-arnd@kernel.org/
Link: https://lore.kernel.org/all/20210324131959.2089129-1-arnd@kernel.org/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
v2: use seq_buf instead of rolling my own
Resending as the second submission somehow got dropped
---
drivers/input/joystick/analog.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/input/joystick/analog.c b/drivers/input/joystick/analog.c
index 882c3c8ba399..3c17bf202af5 100644
--- a/drivers/input/joystick/analog.c
+++ b/drivers/input/joystick/analog.c
@@ -19,6 +19,7 @@
#include <linux/input.h>
#include <linux/gameport.h>
#include <linux/jiffies.h>
+#include <linux/seq_buf.h>
#include <linux/timex.h>
#include <linux/timekeeping.h>
@@ -338,23 +339,24 @@ static void analog_calibrate_timer(struct analog_port *port)
static void analog_name(struct analog *analog)
{
- snprintf(analog->name, sizeof(analog->name), "Analog %d-axis %d-button",
+ struct seq_buf s;
+
+ 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);
if (analog->mask & ANALOG_HATS_ALL)
- snprintf(analog->name, sizeof(analog->name), "%s %d-hat",
- analog->name, hweight16(analog->mask & ANALOG_HATS_ALL));
+ seq_buf_printf(&s, " %d-hat",
+ hweight16(analog->mask & ANALOG_HATS_ALL));
if (analog->mask & ANALOG_HAT_FCS)
- strlcat(analog->name, " FCS", sizeof(analog->name));
+ seq_buf_printf(&s, " FCS");
if (analog->mask & ANALOG_ANY_CHF)
- strlcat(analog->name, (analog->mask & ANALOG_SAITEK) ? " Saitek" : " CHF",
- sizeof(analog->name));
+ seq_buf_printf(&s, (analog->mask & ANALOG_SAITEK) ? " Saitek" : " CHF");
- strlcat(analog->name, (analog->mask & ANALOG_GAMEPAD) ? " gamepad": " joystick",
- sizeof(analog->name));
+ seq_buf_printf(&s, (analog->mask & ANALOG_GAMEPAD) ? " gamepad": " joystick");
}
/*
--
2.29.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] [RESEND] [v2] Input: analog - fix invalid snprintf() call
2021-09-27 10:14 [PATCH] [RESEND] [v2] Input: analog - fix invalid snprintf() call Arnd Bergmann
@ 2021-10-05 20:28 ` Dmitry Torokhov
0 siblings, 0 replies; 2+ messages in thread
From: Dmitry Torokhov @ 2021-10-05 20:28 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Arnd Bergmann, Rasmus Villemoes, Randy Dunlap, Zhang Qilong,
Geert Uytterhoeven, Guenter Roeck, linux-input, linux-kernel
On Mon, Sep 27, 2021 at 12:14:06PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> Overlapping input and output arguments to snprintf() are
> undefined behavior in C99:
>
> drivers/input/joystick/analog.c: In function 'analog_name':
> drivers/input/joystick/analog.c:428:3: error: 'snprintf' argument 4 overlaps destination object 'analog' [-Werror=restrict]
> 428 | snprintf(analog->name, sizeof(analog->name), "%s %d-hat",
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 429 | analog->name, hweight16(analog->mask & ANALOG_HATS_ALL));
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/input/joystick/analog.c:420:40: note: destination object referenced by 'restrict'-qualified argument 1 was declared here
> 420 | static void analog_name(struct analog *analog)
> | ~~~~~~~~~~~~~~~^~~~~~
>
> Change this function to use the simpler seq_buf interface instead.
>
> Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
> Link: https://lore.kernel.org/all/20210323131456.2600132-1-arnd@kernel.org/
> Link: https://lore.kernel.org/all/20210324131959.2089129-1-arnd@kernel.org/
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Applied, thank you.
--
Dmitry
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