Recent changes to the min()/max() macros in include/linux/kernel.h have added a lot of noise when compiling the kernel with Sparse checking enabled. This mostly is due to the *huge* increase in the number of sizeof(void) warnings, a larger number of which can safely be ignored. Add the -Wpointer-arith flag to enable/disable these warnings (along with the warning when applying sizeof to function types as well as warning about pointer arithmetic on these types exactly like the GCC -Wpointer-arith flag) on demand; the warning itself has been disabled by default to reduce the large influx of noise which was inadvertently added by commit 3c8ba0d61d04ced9f8 (kernel.h: Retain constant expression output for max()/min()). Update the manpage to document the new flag and add a validation case for sizeof(void). CC: Kees Cook <keescook@chromium.org> CC: Linus Torvalds <torvalds@linux-foundation.org> CC: Martin Uecker <Martin.Uecker@med.uni-goettingen.de> CC: Al Viro <viro@ZenIV.linux.org.uk> CC: Christopher Li <sparse@chrisli.org> CC: Joey Pabalinas <joeypabalinas@gmail.com> CC: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Joey Pabalinas <joeypabalinas@gmail.com> Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>