@@ -2,9 +2,10 @@
#ifndef __LINUX_OVERFLOW_H
#define __LINUX_OVERFLOW_H
+#include <linux/align.h>
#include <linux/compiler.h>
-#include <linux/limits.h>
#include <linux/const.h>
+#include <linux/limits.h>
/*
* We need to compute the minimum and maximum values representable in a given
@@ -337,6 +338,30 @@ static inline size_t __must_check size_sub(size_t minuend, size_t subtrahend)
*/
#define array3_size(a, b, c) size_mul(size_mul(a, b), c)
+/**
+ * struct_size_with_data() - Calculate size of structure with trailing aligned data.
+ * @p: Pointer to the structure.
+ * @a: Alignment in bytes before trailing data.
+ * @s: Data size in bytes (must not be 0).
+ *
+ * Calculates size of memory needed for structure of @p followed by an
+ * aligned data of size @s.
+ *
+ * Return: number of bytes needed or SIZE_MAX on overflow.
+ */
+#define struct_size_with_data(p, a, s) size_add(ALIGN(sizeof(*(p)), (a)), (s))
+
+/**
+ * struct_data_pointer - Calculate offset of the trailing data reserved with
+ * struct_size_with_data().
+ * @p: Pointer to the structure.
+ * @a: Alignment in bytes before trailing data.
+ *
+ * Return: offset in bytes to the trailing data reserved with
+ * struct_size_with_data().
+ */
+#define struct_data_pointer(p, a) PTR_ALIGN((void *)((p) + 1), (a))
+
/**
* flex_array_size() - Calculate size of a flexible array member
* within an enclosing structure.
Introduce two helper macros to calculate the size of the structure with trailing aligned data and to retrieve the pointer to that data. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- include/linux/overflow.h | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-)