[PATCHv4,05/12] atomics: instrument cmpxchg_double*()

Message ID	20180716113017.3909-6-mark.rutland@arm.com
State	Accepted
Commit	4d2b25f630c731218d04f72580b4de68cb7a6e00
Headers	show Delivered-To: patch@linaro.org Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; From: Mark Rutland <mark.rutland@arm.com> To: mingo@kernel.org, mingo@redhat.com Cc: andy.shevchenko@gmail.com, arnd@arndb.de, aryabinin@virtuozzo.com, boqun.feng@gmail.com, catalin.marinas@arm.com, dvyukov@google.com, glider@google.com, hpa@zytor.com, linux-kernel@vger.kernel.org, mark.rutland@arm.com, parri.andrea@gmail.com, peter@hurleysoftware.com, peterz@infradead.org, tglx@linutronix.de, will.deacon@arm.com, linux-arm-kernel@lists.infradead.org Subject: [PATCHv4 05/12] atomics: instrument cmpxchg_double*() Date: Mon, 16 Jul 2018 12:30:10 +0100 Message-Id: <20180716113017.3909-6-mark.rutland@arm.com> In-Reply-To: <20180716113017.3909-1-mark.rutland@arm.com> References: <20180716113017.3909-1-mark.rutland@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk
Series	atomics: generate atomic headers / instrument arm64 \| expand [PATCHv4,00/12] atomics: generate atomic headers / instrument arm64 [PATCHv4,01/12] atomic/tty: Fix up atomic abuse in ldsem [PATCHv4,02/12] atomics/x86: reduce arch_cmpxchg64() instrumentation [PATCHv4,03/12] atomics: simplify cmpxchg() instrumentation [PATCHv4,04/12] atomics/treewide: instrument xchg() [PATCHv4,05/12] atomics: instrument cmpxchg_double() [PATCHv4,06/12] atomics/treewide: rework ordering barriers [PATCHv4,07/12] atomics: add common header generation files [PATCHv4,08/12] atomics: switch to generated fallbacks [PATCHv4,09/12] atomics: switch to generated atomic-long [PATCHv4,10/12] atomics: switch to generated instrumentation [PATCHv4,11/12] atomics: check generated headers are up-to-date [PATCHv4,12/12] arm64: use instrumented atomics

Message ID

20180716113017.3909-6-mark.rutland@arm.com

State

Accepted

Commit

4d2b25f630c731218d04f72580b4de68cb7a6e00

Headers

Received-SPF: pass (google.com: best guess record for domain of
	linux-kernel-owner@vger.kernel.org designates 209.132.180.67
	as permitted sender) client-ip=209.132.180.67; 
From: Mark Rutland <mark.rutland@arm.com>
To: mingo@kernel.org, mingo@redhat.com
Cc: andy.shevchenko@gmail.com, arnd@arndb.de, aryabinin@virtuozzo.com,
	boqun.feng@gmail.com, catalin.marinas@arm.com, dvyukov@google.com,
	glider@google.com, hpa@zytor.com, linux-kernel@vger.kernel.org,
	mark.rutland@arm.com, parri.andrea@gmail.com,
	peter@hurleysoftware.com, peterz@infradead.org, tglx@linutronix.de,
	will.deacon@arm.com, linux-arm-kernel@lists.infradead.org
Subject: [PATCHv4 05/12] atomics: instrument cmpxchg_double*()
Date: Mon, 16 Jul 2018 12:30:10 +0100
Message-Id: <20180716113017.3909-6-mark.rutland@arm.com>
In-Reply-To: <20180716113017.3909-1-mark.rutland@arm.com>
References: <20180716113017.3909-1-mark.rutland@arm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Series

atomics: generate atomic headers / instrument arm64 | expand

Commit Message

Mark Rutland July 16, 2018, 11:30 a.m. UTC

We currently don't instrument cmpxchg_double() and
cmpxchg_double_local() due to compilation issues reported in the past,
which are supposedly related to GCC bug 72873 [1], reported when GCC 7
was not yet released. This bug only applies to x86-64, and does not
apply to other architectures.

While the test case for GCC bug 72873 triggers issues with released
versions of GCC, the instrumented kernel code compiles fine for all
configurations I have tried, and it is unclear how the two cases
are/were related.

As we can't reproduce the kernel build failures, let's instrument
cmpxchg_double*() again. We can revisit the issue if build failures
reappear.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Acked-by: Will Deacon <will.deacon@arm.com>

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
---
 include/asm-generic/atomic-instrumented.h | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

-- 
2.11.0

diff --git a/include/asm-generic/atomic-instrumented.h b/include/asm-generic/atomic-instrumented.h
index 53481b6eacdf..0d4b1d3dbc1e 100644
--- a/include/asm-generic/atomic-instrumented.h
+++ b/include/asm-generic/atomic-instrumented.h
@@ -450,23 +450,18 @@  static __always_inline bool atomic64_add_negative(s64 i, atomic64_t *v)
 	arch_cmpxchg64_local(__ai_ptr, (old), (new));			\
 })
 
-/*
- * Originally we had the following code here:
- *     __typeof__(p1) ____p1 = (p1);
- *     kasan_check_write(____p1, 2 * sizeof(*____p1));
- *     arch_cmpxchg_double(____p1, (p2), (o1), (o2), (n1), (n2));
- * But it leads to compilation failures (see gcc issue 72873).
- * So for now it's left non-instrumented.
- * There are few callers of cmpxchg_double(), so it's not critical.
- */
 #define cmpxchg_double(p1, p2, o1, o2, n1, n2)				\
 ({									\
-	arch_cmpxchg_double((p1), (p2), (o1), (o2), (n1), (n2));	\
+	typeof(p1) __ai_p1 = (p1);					\
+	kasan_check_write(__ai_p1, 2 * sizeof(*__ai_p1));		\
+	arch_cmpxchg_double(__ai_p1, (p2), (o1), (o2), (n1), (n2));	\
 })
 
-#define cmpxchg_double_local(p1, p2, o1, o2, n1, n2)			\
-({									\
-	arch_cmpxchg_double_local((p1), (p2), (o1), (o2), (n1), (n2));	\
+#define cmpxchg_double_local(p1, p2, o1, o2, n1, n2)				\
+({										\
+	typeof(p1) __ai_p1 = (p1);						\
+	kasan_check_write(__ai_p1, 2 * sizeof(*__ai_p1));			\
+	arch_cmpxchg_double_local(__ai_p1, (p2), (o1), (o2), (n1), (n2));	\
 })
 
 #endif /* _LINUX_ATOMIC_INSTRUMENTED_H */

[PATCHv4,05/12] atomics: instrument cmpxchg_double*()

Commit Message

Patch