[PATCH v5 03/20] gpio: uapi: define GPIO_MAX_NAME_SIZE for array sizes

From: Kent Gibson
Date: Thu Aug 27 2020 - 10:25:37 EST


Replace constant array sizes with a macro constant to clarify the source
of array sizes, provide a place to document any constraints on the size,
and to simplify array sizing in userspace if constructing structs
from their composite fields.

Signed-off-by: Kent Gibson <warthog618@xxxxxxxxx>
---
include/uapi/linux/gpio.h | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h
index 9c27cecf406f..285cc10355b2 100644
--- a/include/uapi/linux/gpio.h
+++ b/include/uapi/linux/gpio.h
@@ -14,6 +14,11 @@
#include <linux/ioctl.h>
#include <linux/types.h>

+/*
+ * The maximum size of name and label arrays.
+ */
+#define GPIO_MAX_NAME_SIZE 32
+
/**
* struct gpiochip_info - Information about a certain GPIO chip
* @name: the Linux kernel name of this GPIO chip
@@ -22,8 +27,8 @@
* @lines: number of GPIO lines on this chip
*/
struct gpiochip_info {
- char name[32];
- char label[32];
+ char name[GPIO_MAX_NAME_SIZE];
+ char label[GPIO_MAX_NAME_SIZE];
__u32 lines;
};

@@ -52,8 +57,8 @@ struct gpiochip_info {
struct gpioline_info {
__u32 line_offset;
__u32 flags;
- char name[32];
- char consumer[32];
+ char name[GPIO_MAX_NAME_SIZE];
+ char consumer[GPIO_MAX_NAME_SIZE];
};

/* Maximum number of requested handles */
@@ -123,7 +128,7 @@ struct gpiohandle_request {
__u32 lineoffsets[GPIOHANDLES_MAX];
__u32 flags;
__u8 default_values[GPIOHANDLES_MAX];
- char consumer_label[32];
+ char consumer_label[GPIO_MAX_NAME_SIZE];
__u32 lines;
int fd;
};
@@ -182,7 +187,7 @@ struct gpioevent_request {
__u32 lineoffset;
__u32 handleflags;
__u32 eventflags;
- char consumer_label[32];
+ char consumer_label[GPIO_MAX_NAME_SIZE];
int fd;
};

--
2.28.0