svn commit: r361723 - head/sys/compat/linuxkpi/common/include/linux

[Hans Petter Selasky]

Author: hselasky
Date: Tue Jun  2 10:19:45 2020
New Revision: 361723
URL: https://svnweb.freebsd.org/changeset/base/361723

Log:
  Implement struct_size() function macro in the LinuxKPI.
  
  MFC after:	1 week
  Sponsored by:	Mellanox Technologies

Modified:
  head/sys/compat/linuxkpi/common/include/linux/kernel.h

Modified: head/sys/compat/linuxkpi/common/include/linux/kernel.h
==============================================================================
--- head/sys/compat/linuxkpi/common/include/linux/kernel.h	Tue Jun  2 09:45:43 2020	(r361722)
+++ head/sys/compat/linuxkpi/common/include/linux/kernel.h	Tue Jun  2 10:19:45 2020	(r361723)
@@ -555,4 +555,10 @@ linux_ratelimited(linux_ratelimit_t *rl)
 	return (ppsratecheck(&rl->lasttime, &rl->counter, 1));
 }
 
+#define	struct_size(ptr, field, num) ({ \
+	const size_t __size = offsetof(__typeof(*(ptr)), field); \
+	const size_t __max = (SIZE_MAX - __size) / sizeof((ptr)->field[0]); \
+	((num) > __max) ? SIZE_MAX : (__size + sizeof((ptr)->field[0]) * (num)); \
+})
+
 #endif	/* _LINUX_KERNEL_H_ */