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From: Vincenzo Frascino <vincenzo.frascino@arm.com>
To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Cc: vincenzo.frascino@arm.com, ard.biesheuvel@linaro.org,
	ndesaulniers@google.com, catalin.marinas@arm.com,
	will@kernel.org, tglx@linutronix.de
Subject: [PATCH 2/4] arm64: vdso32: Detect binutils support for dmb ishld
Date: Thu, 26 Sep 2019 07:03:51 +0100	[thread overview]
Message-ID: <20190926060353.54894-3-vincenzo.frascino@arm.com> (raw)
In-Reply-To: <20190926060353.54894-1-vincenzo.frascino@arm.com>

As reported by Will Deacon, older versions of binutils that do not
support certain types of memory barriers can cause build failure of the
vdso32 library.

Add a compilation time mechanism that detects if binutils supports those
instructions and configure the kernel accordingly.

Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 arch/arm64/include/asm/vdso/compat_barrier.h | 2 +-
 arch/arm64/kernel/vdso32/Makefile            | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/vdso/compat_barrier.h b/arch/arm64/include/asm/vdso/compat_barrier.h
index fb60a88b5ed4..3fd8fd6d8fc2 100644
--- a/arch/arm64/include/asm/vdso/compat_barrier.h
+++ b/arch/arm64/include/asm/vdso/compat_barrier.h
@@ -20,7 +20,7 @@
 
 #define dmb(option) __asm__ __volatile__ ("dmb " #option : : : "memory")
 
-#if __LINUX_ARM_ARCH__ >= 8
+#if __LINUX_ARM_ARCH__ >= 8 && defined(CONFIG_AS_DMB_ISHLD)
 #define aarch32_smp_mb()	dmb(ish)
 #define aarch32_smp_rmb()	dmb(ishld)
 #define aarch32_smp_wmb()	dmb(ishst)
diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile
index 1fba0776ed40..1a3299d901b1 100644
--- a/arch/arm64/kernel/vdso32/Makefile
+++ b/arch/arm64/kernel/vdso32/Makefile
@@ -55,6 +55,9 @@ endif
 VDSO_CAFLAGS += -fPIC -fno-builtin -fno-stack-protector
 VDSO_CAFLAGS += -DDISABLE_BRANCH_PROFILING
 
+# Check for binutils support for dmb ishld
+dmbinstr := $(call as-instr,dmb ishld,-DCONFIG_AS_DMB_ISHLD=1)
+
 # Try to compile for ARMv8. If the compiler is too old and doesn't support it,
 # fall back to v7. There is no easy way to check for what architecture the code
 # is being compiled, so define a macro specifying that (see arch/arm/Makefile).
@@ -62,7 +65,7 @@ VDSO_CAFLAGS += $(call cc32-option,-march=armv8-a -D__LINUX_ARM_ARCH__=8,\
                                    -march=armv7-a -D__LINUX_ARM_ARCH__=7)
 
 VDSO_CFLAGS := $(VDSO_CAFLAGS)
-VDSO_CFLAGS += -DENABLE_COMPAT_VDSO=1
+VDSO_CFLAGS += -DENABLE_COMPAT_VDSO=1 $(dmbinstr)
 # KBUILD_CFLAGS from top-level Makefile
 VDSO_CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
                -fno-strict-aliasing -fno-common \
-- 
2.23.0


  parent reply	other threads:[~2019-09-26  6:04 UTC|newest]

Thread overview: 67+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-20 14:27 Problems with arm64 compat vdso Will Deacon
2019-09-20 16:33 ` Vincenzo Frascino
2019-09-23 16:41   ` Ard Biesheuvel
2019-09-24 12:11     ` Vincenzo Frascino
2019-09-24 18:06       ` Nick Desaulniers
2019-09-24 20:42         ` Vincenzo Frascino
2019-09-25 15:58     ` Ard Biesheuvel
2019-09-26  6:03 ` [PATCH 0/4] arm64: vdso32: Address various issues Vincenzo Frascino
2019-09-26  6:03   ` [PATCH 1/4] arm64: vdso32: Introduce COMPAT_CC_IS_GCC Vincenzo Frascino
2019-09-26  8:06     ` Catalin Marinas
2019-09-26 10:56       ` Vincenzo Frascino
2019-09-26 11:02         ` Vincenzo Frascino
2019-09-26 15:23           ` Catalin Marinas
2019-09-26 12:22         ` Vincenzo Frascino
2019-09-26 15:17           ` Catalin Marinas
2019-09-26 20:17             ` Vincenzo Frascino
2019-09-26  6:03   ` Vincenzo Frascino [this message]
2019-09-26  8:30     ` [PATCH 2/4] arm64: vdso32: Detect binutils support for dmb ishld Catalin Marinas
2019-09-26 10:59       ` Vincenzo Frascino
2019-09-26  6:03   ` [PATCH 3/4] arm64: vdso32: Fix compilation warning Vincenzo Frascino
2019-09-26  8:32     ` Catalin Marinas
2019-09-26 11:03       ` Vincenzo Frascino
2019-09-26  6:03   ` [PATCH 4/4] arm64: Remove gettimeofday.S Vincenzo Frascino
2019-09-26  8:34     ` Catalin Marinas
2019-09-26 13:38 ` [PATCH v2 0/4] arm64: vdso32: Address various issues Vincenzo Frascino
2019-09-26 13:38   ` [PATCH v2 1/4] arm64: vdso32: Introduce COMPAT_CC_IS_GCC Vincenzo Frascino
2019-09-26 15:13     ` Catalin Marinas
2019-09-26 13:38   ` [PATCH v2 2/4] arm64: vdso32: Detect binutils support for dmb ishld Vincenzo Frascino
2019-09-26 14:26     ` Catalin Marinas
2019-09-26 20:19       ` Vincenzo Frascino
2019-09-26 15:59     ` Catalin Marinas
2019-09-26 21:17       ` Vincenzo Frascino
2019-09-26 16:23     ` Nick Desaulniers
2019-09-26 13:38   ` [PATCH v2 3/4] arm64: vdso32: Fix compilation warning Vincenzo Frascino
2019-09-26 15:22     ` Catalin Marinas
2019-09-26 13:38   ` [PATCH v2 4/4] arm64: Remove gettimeofday.S Vincenzo Frascino
2019-09-26 15:31   ` [PATCH v2 0/4] arm64: vdso32: Address various issues Catalin Marinas
2019-09-26 20:29     ` Vincenzo Frascino
2019-09-26 21:43 ` [PATCH v3 0/5]arm64: " Vincenzo Frascino
2019-09-26 21:43   ` [PATCH v3 1/5] arm64: vdso32: Introduce COMPAT_CC_IS_GCC Vincenzo Frascino
2019-09-27  9:24     ` Catalin Marinas
2019-10-01 13:14     ` Will Deacon
2019-10-01 13:27       ` Catalin Marinas
2019-10-01 14:20         ` Vincenzo Frascino
2019-10-01 14:20           ` Will Deacon
2019-10-01 14:37             ` Vincenzo Frascino
2019-10-01 14:43               ` Will Deacon
2019-10-01 14:59                 ` Vincenzo Frascino
2019-10-01 15:30                 ` Catalin Marinas
2019-10-01 16:46                   ` Will Deacon
2019-10-01 16:59                     ` Nick Desaulniers
2019-10-01 17:07                       ` Will Deacon
2019-10-01 17:12                         ` Nick Desaulniers
2019-10-01 17:14                           ` Will Deacon
2019-09-26 21:43   ` [PATCH v3 2/5] arm64: vdso32: Detect binutils support for dmb ishld Vincenzo Frascino
2019-09-27  9:25     ` Catalin Marinas
2019-10-01 13:26     ` Will Deacon
2019-10-01 14:23       ` Vincenzo Frascino
2019-09-26 21:43   ` [PATCH v3 3/5] arm64: vdso32: Fix compilation warning Vincenzo Frascino
2019-09-27  9:26     ` Catalin Marinas
2019-10-01 13:21     ` Will Deacon
2019-10-01 14:41       ` Vincenzo Frascino
2019-09-26 21:43   ` [PATCH v3 4/5] arm64: Remove gettimeofday.S Vincenzo Frascino
2019-09-26 21:43   ` [PATCH v3 5/5] arm64: vdso32: Remove jump label config option in Makefile Vincenzo Frascino
2019-09-27  9:27     ` Catalin Marinas
2019-09-27 10:46   ` [PATCH v3 0/5]arm64: vdso32: Address various issues Catalin Marinas
2019-10-01 13:27   ` Will Deacon

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