Commit-ID: ef50c046338948df9f23fb5ef853efda0274c7b3 Gitweb: http://git.kernel.org/tip/ef50c046338948df9f23fb5ef853efda0274c7b3 Author: Daniel Wagner <daniel.wagner@xxxxxxxxxxxx> AuthorDate: Fri, 19 Feb 2016 09:46:38 +0100 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitDate: Thu, 25 Feb 2016 11:27:16 +0100 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@xxxxxxxxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: linux-rt-users@xxxxxxxxxxxxxxx Cc: Boqun Feng <boqun.feng@xxxxxxxxx> Cc: Marcelo Tosatti <mtosatti@xxxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1455871601-27484-3-git-send-email-wagi@xxxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> --- Makefile | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Makefile b/Makefile index 6c1a3c2..4513509 100644 --- a/Makefile +++ b/Makefile @@ -773,6 +773,9 @@ 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) -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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