From: Andi Kleen <ak@linux.intel.com>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Måns Rullgård" <mans@mansr.com>,
"Russell King - ARM Linux" <linux@arm.linux.org.uk>,
"Nicolas Pitre" <nico@fluxnic.net>,
"Will Deacon" <Will.Deacon@arm.com>,
lkml <linux-kernel@vger.kernel.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
sam@ravnborg.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] Disable -fconserve-stack on ARM
Date: Tue, 31 May 2011 11:01:07 -0700 [thread overview]
Message-ID: <20110531180107.GA9261@alboin.amr.corp.intel.com> (raw)
In-Reply-To: <20110531163026.GB771@e102109-lin.cambridge.arm.com>
> Didn't work, on the gcc command line we get -fno-conserve-stack followed
> by -fconserve-stack from the top makefile and it seems that the latter
> takes priority.
Ah ok need to move it up then too in the top level Makefile.
Like this.
-Andi
---
Disable -fconserve-stack on ARM v2
There are reports that -fconserve-stack misaligns variables on the stack.
Disable it for ARM to work around this gcc bug.
v2: Move top level flags definition up
Signed-off-by: Andi Kleen <ak@linux.intel.com>
diff --git a/Makefile b/Makefile
index 529d93f..08d848f 100644
--- a/Makefile
+++ b/Makefile
@@ -564,6 +564,10 @@ else
KBUILD_CFLAGS += -O2
endif
+# conserve stack if available
+# do this early so that an architecture can override it.
+KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
+
include $(srctree)/arch/$(SRCARCH)/Makefile
ifneq ($(CONFIG_FRAME_WARN),0)
@@ -629,9 +633,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
# disable invalid "can't wrap" optimizations for signed / pointers
KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
-# conserve stack if available
-KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
-
# use the deterministic mode of AR if available
KBUILD_ARFLAGS := $(call ar-option,D)
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index f5b2b39..902fec9 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -41,6 +41,10 @@ ifeq ($(CONFIG_CC_STACKPROTECTOR),y)
KBUILD_CFLAGS +=-fstack-protector
endif
+# ARM gcc developers unfortunately broke -fconserve-stack. It misaligns
+# variables on the stack
+KBUILD_CFLAGS += $(call cc-option,-fno-conserve-stack)
+
ifeq ($(CONFIG_CPU_BIG_ENDIAN),y)
KBUILD_CPPFLAGS += -mbig-endian
AS += -EB
WARNING: multiple messages have this Message-ID (diff)
From: ak@linux.intel.com (Andi Kleen)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] Disable -fconserve-stack on ARM
Date: Tue, 31 May 2011 11:01:07 -0700 [thread overview]
Message-ID: <20110531180107.GA9261@alboin.amr.corp.intel.com> (raw)
In-Reply-To: <20110531163026.GB771@e102109-lin.cambridge.arm.com>
> Didn't work, on the gcc command line we get -fno-conserve-stack followed
> by -fconserve-stack from the top makefile and it seems that the latter
> takes priority.
Ah ok need to move it up then too in the top level Makefile.
Like this.
-Andi
---
Disable -fconserve-stack on ARM v2
There are reports that -fconserve-stack misaligns variables on the stack.
Disable it for ARM to work around this gcc bug.
v2: Move top level flags definition up
Signed-off-by: Andi Kleen <ak@linux.intel.com>
diff --git a/Makefile b/Makefile
index 529d93f..08d848f 100644
--- a/Makefile
+++ b/Makefile
@@ -564,6 +564,10 @@ else
KBUILD_CFLAGS += -O2
endif
+# conserve stack if available
+# do this early so that an architecture can override it.
+KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
+
include $(srctree)/arch/$(SRCARCH)/Makefile
ifneq ($(CONFIG_FRAME_WARN),0)
@@ -629,9 +633,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
# disable invalid "can't wrap" optimizations for signed / pointers
KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
-# conserve stack if available
-KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
-
# use the deterministic mode of AR if available
KBUILD_ARFLAGS := $(call ar-option,D)
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index f5b2b39..902fec9 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -41,6 +41,10 @@ ifeq ($(CONFIG_CC_STACKPROTECTOR),y)
KBUILD_CFLAGS +=-fstack-protector
endif
+# ARM gcc developers unfortunately broke -fconserve-stack. It misaligns
+# variables on the stack
+KBUILD_CFLAGS += $(call cc-option,-fno-conserve-stack)
+
ifeq ($(CONFIG_CPU_BIG_ENDIAN),y)
KBUILD_CPPFLAGS += -mbig-endian
AS += -EB
next prev parent reply other threads:[~2011-05-31 18:01 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-23 11:16 [PATCH] ARM: Do not allow unaligned accesses when CONFIG_ALIGNMENT_TRAP Catalin Marinas
2011-05-23 12:30 ` Måns Rullgård
2011-05-23 13:25 ` Russell King - ARM Linux
2011-05-23 13:21 ` Russell King - ARM Linux
2011-05-23 13:51 ` Catalin Marinas
2011-05-23 14:37 ` Måns Rullgård
2011-05-23 14:41 ` Catalin Marinas
2011-05-23 14:52 ` Russell King - ARM Linux
2011-05-24 9:39 ` Catalin Marinas
2011-05-24 14:17 ` Måns Rullgård
2011-05-24 15:26 ` Catalin Marinas
2011-05-24 16:23 ` Måns Rullgård
2011-05-24 17:26 ` Nicolas Pitre
2011-05-24 17:13 ` Dave Martin
2011-05-25 11:14 ` Catalin Marinas
2011-05-25 12:43 ` Dave Martin
2011-05-25 13:32 ` Måns Rullgård
2011-05-25 14:05 ` Dave Martin
2011-05-25 14:48 ` Måns Rullgård
2011-05-25 14:50 ` Catalin Marinas
2011-05-25 14:53 ` Måns Rullgård
2011-05-26 17:10 ` Will Deacon
2011-05-26 17:10 ` Will Deacon
2011-05-26 18:14 ` Måns Rullgård
2011-05-26 18:14 ` Måns Rullgård
2011-05-26 19:58 ` Andi Kleen
2011-05-26 19:58 ` Andi Kleen
2011-05-26 21:03 ` Nicolas Pitre
2011-05-26 21:03 ` Nicolas Pitre
2011-05-26 21:10 ` Andi Kleen
2011-05-26 21:10 ` Andi Kleen
2011-05-26 21:26 ` Måns Rullgård
2011-05-26 21:26 ` Måns Rullgård
2011-05-27 10:05 ` Will Deacon
2011-05-27 10:05 ` Will Deacon
2011-05-27 16:53 ` Andi Kleen
2011-05-27 16:53 ` Andi Kleen
2011-05-26 21:51 ` Russell King - ARM Linux
2011-05-26 21:51 ` Russell King - ARM Linux
2011-05-26 22:29 ` Andi Kleen
2011-05-26 22:29 ` Andi Kleen
2011-05-27 8:38 ` Catalin Marinas
2011-05-27 8:38 ` Catalin Marinas
2011-05-27 8:54 ` Russell King - ARM Linux
2011-05-27 8:54 ` Russell King - ARM Linux
2011-05-27 9:51 ` Catalin Marinas
2011-05-27 9:51 ` Catalin Marinas
2011-05-27 9:56 ` Catalin Marinas
2011-05-27 9:56 ` Catalin Marinas
2011-05-27 12:46 ` Måns Rullgård
2011-05-27 12:46 ` Måns Rullgård
2011-05-28 15:34 ` [PATCH] Disable -fconserve-stack on ARM Andi Kleen
2011-05-28 15:34 ` Andi Kleen
2011-05-31 16:30 ` Catalin Marinas
2011-05-31 16:30 ` Catalin Marinas
2011-05-31 18:01 ` Andi Kleen [this message]
2011-05-31 18:01 ` Andi Kleen
2011-06-02 13:08 ` Catalin Marinas
2011-06-02 13:08 ` Catalin Marinas
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