Merge tag 'Wcast-function-type-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux

Pull cast-function-type warning addition from Gustavo A. R. Silva:
"This globally enables -Wcast-function-type.

We need to make sure new function cast mismatches are not introduced
in the kernel in order to avoid tripping CFI checking"

* tag 'Wcast-function-type-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
Makefile: Enable -Wcast-function-type

Makefile

···
 # disable pointer signed / unsigned warnings in gcc 4.0
 KBUILD_CFLAGS += -Wno-pointer-sign
 
+# In order to make sure new function cast mismatches are not introduced
+# in the kernel (to avoid tripping CFI checking), the kernel should be
+# globally built with -Wcast-function-type.
+KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
+
 # disable stringop warnings in gcc 8+
 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)