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authorDaniel Wagner <daniel.wagner@bmw-carit.de>2015-11-30 11:34:40 +0100
committerClark Williams <williams@redhat.com>2016-02-22 08:33:06 -0600
commit410b1c243e0e9dd0b0031f20b1918b61e6024b6d (patch)
treeebea00794f99a400bc3d4862fc6f6b5c568fa724
parent1fd8bd22e9c7a124e102fca6f877cc3605453447 (diff)
downloadrt-linux-410b1c243e0e9dd0b0031f20b1918b61e6024b6d.tar.gz
kbuild: Add option to turn incompatible pointer check into error
With the introduction of the simple wait API we have two very similar APIs in the kernel. For example wake_up() and swake_up() is only one character away. Although the compiler will warn happily the wrong usage it keeps on going an even links the kernel. Thomas and Peter would rather like to see early missuses reported as error early on. In a first attempt we tried to wrap all swait and wait calls into a macro which has an compile time type assertion. The result was pretty ugly and wasn't able to catch all wrong usages. woken_wake_function(), autoremove_wake_function() and wake_bit_function() are assigned as function pointers. Wrapping them with a macro around is not possible. Prefixing them with '_' was also not a real option because there some users in the kernel which do use them as well. All in all this attempt looked to intrusive and too ugly. An alternative is to turn the pointer type check into an error which catches wrong type uses. Obviously not only the swait/wait ones. That isn't a bad thing either. Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--Makefile3
1 files changed, 3 insertions, 0 deletions
diff --git a/Makefile b/Makefile
index c6a265b52c93c7..53e05540cf2c95 100644
--- a/Makefile
+++ b/Makefile
@@ -767,6 +767,9 @@ KBUILD_CFLAGS += $(call cc-option,-Werror=strict-prototypes)
# Prohibit date/time macros, which would make the build non-deterministic
KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
+# enforce correct pointer usage
+KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
+
# use the deterministic mode of AR if available
KBUILD_ARFLAGS := $(call ar-option,D)