From: Daniel Wagner <daniel.wagner@bmw-carit.de>
To: linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org,
Marcelo Tosatti <mtosatti@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
"Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Steven Rostedt <rostedt@goodmis.org>,
Boqun Feng <boqun.feng@gmail.com>,
Daniel Wagner <daniel.wagner@bmw-carit.de>
Subject: [PATCH tip v6 2/5] kbuild: Add option to turn incompatible pointer check into error
Date: Thu, 28 Jan 2016 15:44:27 +0100 [thread overview]
Message-ID: <1453992270-4688-3-git-send-email-daniel.wagner@bmw-carit.de> (raw)
In-Reply-To: <1453992270-4688-1-git-send-email-daniel.wagner@bmw-carit.de>
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>
---
Makefile | 3 +++
1 file changed, 3 insertions(+)
diff --git a/Makefile b/Makefile
index 9d94ade..653fd08 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)
--
2.5.0
next prev parent reply other threads:[~2016-01-28 14:51 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-28 14:44 [PATCH tip v6 0/5] Simple wait queue support Daniel Wagner
2016-01-28 14:44 ` [PATCH tip v6 1/5] wait.[ch]: Introduce the simple waitqueue (swait) implementation Daniel Wagner
2016-01-28 14:44 ` Daniel Wagner [this message]
2016-01-29 12:17 ` [PATCH tip v6 2/5] kbuild: Add option to turn incompatible pointer check into error Daniel Wagner
2016-01-29 18:55 ` Paul Gortmaker
2016-02-01 6:49 ` Daniel Wagner
2016-02-05 8:16 ` Daniel Wagner
2016-02-07 4:39 ` Paul Gortmaker
2016-02-17 13:04 ` Daniel Wagner
2016-01-28 14:44 ` [PATCH tip v6 3/5] KVM: use simple waitqueue for vcpu->wq Daniel Wagner
2016-01-29 12:18 ` Daniel Wagner
2016-01-28 14:44 ` [PATCH tip v6 4/5] rcu: Do not call rcu_nocb_gp_cleanup() while holding rnp->lock Daniel Wagner
2016-01-28 14:44 ` [PATCH tip v6 5/5] rcu: use simple wait queues where possible in rcutree Daniel Wagner
2016-01-29 13:23 ` [PATCH] video: Use bool instead int pointer for get_opt_bool() argument Daniel Wagner
2016-01-29 13:28 ` [PATCH] MIPS: Differentiate between 32 and 64 bit ELF header Daniel Wagner
2016-02-01 0:52 ` Maciej W. Rozycki
2016-02-01 16:07 ` Daniel Wagner
2016-02-06 17:16 ` Maciej W. Rozycki
2016-02-08 15:44 ` [PATCH v3 0/3] " Daniel Wagner
2016-02-08 15:44 ` [PATCH v3 1/3] mips: Use arch specific auxvec.h instead of generic-asm version Daniel Wagner
2016-02-08 17:19 ` Maciej W. Rozycki
2016-02-09 7:01 ` Daniel Wagner
2016-02-09 11:46 ` Maciej W. Rozycki
2016-02-09 12:37 ` Daniel Wagner
2016-02-09 14:51 ` Maciej W. Rozycki
2016-02-10 8:51 ` Daniel Wagner
2016-02-08 15:44 ` [PATCH v3 2/3] crash_dump: Add vmcore_elf32_check_arch Daniel Wagner
2016-02-08 17:05 ` Maciej W. Rozycki
2016-02-08 15:44 ` [PATCH v3 3/3] mips: Differentiate between 32 and 64 bit ELF header Daniel Wagner
2016-02-08 16:22 ` kbuild test robot
2016-02-09 8:03 ` Daniel Wagner
2016-02-09 12:32 ` Maciej W. Rozycki
2016-02-09 12:38 ` Daniel Wagner
2016-02-09 19:44 ` Maciej W. Rozycki
2016-02-10 6:28 ` Daniel Wagner
2016-02-10 9:21 ` [PATCH v4 0/2] " Daniel Wagner
2016-02-10 9:21 ` [PATCH v4 1/2] crash_dump: Add vmcore_elf32_check_arch Daniel Wagner
2016-02-10 9:21 ` [PATCH v4 2/2] mips: Differentiate between 32 and 64 bit ELF header Daniel Wagner
2016-02-11 10:49 ` Ralf Baechle
2016-02-11 12:04 ` Maciej W. Rozycki
2016-02-11 12:14 ` Daniel Wagner
2016-02-11 14:58 ` Maciej W. Rozycki
2016-02-11 15:30 ` Ralf Baechle
2016-02-08 16:58 ` [PATCH v3 3/3] " Maciej W. Rozycki
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