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-rw-r--r--Makefile4
-rw-r--r--arch/Kconfig24
-rw-r--r--arch/ia64/Kconfig1
-rw-r--r--arch/ia64/Makefile2
-rw-r--r--arch/x86/Kconfig2
-rw-r--r--arch/x86/boot/compressed/head_64.S8
-rw-r--r--arch/x86/include/asm/linkage.h4
-rw-r--r--include/asm-generic/vmlinux.lds.h4
-rw-r--r--include/linux/linkage.h4
-rw-r--r--lib/Kconfig.debug1
10 files changed, 44 insertions, 10 deletions
diff --git a/Makefile b/Makefile
index f41ec8c8426b..141e1bcc0671 100644
--- a/Makefile
+++ b/Makefile
@@ -1004,8 +1004,8 @@ KBUILD_CFLAGS += $(CC_FLAGS_CFI)
export CC_FLAGS_CFI
endif
-ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
-KBUILD_CFLAGS += -falign-functions=64
+ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
+KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
endif
# arch Makefile may override CC so keep this after arch Makefile is included
diff --git a/arch/Kconfig b/arch/Kconfig
index 8f138e580d1a..402580253802 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -1428,4 +1428,28 @@ source "kernel/gcov/Kconfig"
source "scripts/gcc-plugins/Kconfig"
+config FUNCTION_ALIGNMENT_4B
+ bool
+
+config FUNCTION_ALIGNMENT_8B
+ bool
+
+config FUNCTION_ALIGNMENT_16B
+ bool
+
+config FUNCTION_ALIGNMENT_32B
+ bool
+
+config FUNCTION_ALIGNMENT_64B
+ bool
+
+config FUNCTION_ALIGNMENT
+ int
+ default 64 if FUNCTION_ALIGNMENT_64B
+ default 32 if FUNCTION_ALIGNMENT_32B
+ default 16 if FUNCTION_ALIGNMENT_16B
+ default 8 if FUNCTION_ALIGNMENT_8B
+ default 4 if FUNCTION_ALIGNMENT_4B
+ default 0
+
endmenu
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index c6e06cdc738f..d7e4a24e8644 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -63,6 +63,7 @@ config IA64
select NUMA if !FLATMEM
select PCI_MSI_ARCH_FALLBACKS if PCI_MSI
select ZONE_DMA32
+ select FUNCTION_ALIGNMENT_32B
default y
help
The Itanium Processor Family is Intel's 64-bit successor to
diff --git a/arch/ia64/Makefile b/arch/ia64/Makefile
index 56c4bb276b6e..d553ab7022fe 100644
--- a/arch/ia64/Makefile
+++ b/arch/ia64/Makefile
@@ -23,7 +23,7 @@ KBUILD_AFLAGS_KERNEL := -mconstant-gp
EXTRA :=
cflags-y := -pipe $(EXTRA) -ffixed-r13 -mfixed-range=f12-f15,f32-f127 \
- -falign-functions=32 -frename-registers -fno-optimize-sibling-calls
+ -frename-registers -fno-optimize-sibling-calls
KBUILD_CFLAGS_KERNEL := -mconstant-gp
GAS_STATUS = $(shell $(srctree)/arch/ia64/scripts/check-gas "$(CC)" "$(OBJDUMP)")
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 6d1879ef933a..f408fa87ed94 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -290,6 +290,8 @@ config X86
select X86_FEATURE_NAMES if PROC_FS
select PROC_PID_ARCH_STATUS if PROC_FS
select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX
+ select FUNCTION_ALIGNMENT_16B if X86_64 || X86_ALIGNMENT_16
+ select FUNCTION_ALIGNMENT_4B
imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index d33f060900d2..190b803eb787 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -38,6 +38,14 @@
#include "pgtable.h"
/*
+ * Fix alignment at 16 bytes. Following CONFIG_FUNCTION_ALIGNMENT will result
+ * in assembly errors due to trying to move .org backward due to the excessive
+ * alignment.
+ */
+#undef __ALIGN
+#define __ALIGN .balign 16, 0x90
+
+/*
* Locally defined symbols should be marked hidden:
*/
.hidden _bss
diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h
index f484d656d34e..9ee0e2851742 100644
--- a/arch/x86/include/asm/linkage.h
+++ b/arch/x86/include/asm/linkage.h
@@ -14,10 +14,8 @@
#ifdef __ASSEMBLY__
-#if defined(CONFIG_X86_64) || defined(CONFIG_X86_ALIGNMENT_16)
-#define __ALIGN .p2align 4, 0x90
+#define __ALIGN .balign CONFIG_FUNCTION_ALIGNMENT, 0x90;
#define __ALIGN_STR __stringify(__ALIGN)
-#endif
#if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
#define RET jmp __x86_return_thunk
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index c15de165ec8f..335b5711a7ed 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -81,8 +81,8 @@
#define RO_EXCEPTION_TABLE
#endif
-/* Align . to a 8 byte boundary equals to maximum function alignment. */
-#define ALIGN_FUNCTION() . = ALIGN(8)
+/* Align . function alignment. */
+#define ALIGN_FUNCTION() . = ALIGN(CONFIG_FUNCTION_ALIGNMENT)
/*
* LD_DEAD_CODE_DATA_ELIMINATION option enables -fdata-sections, which
diff --git a/include/linux/linkage.h b/include/linux/linkage.h
index 1feab6136b5b..5c8865bb59d9 100644
--- a/include/linux/linkage.h
+++ b/include/linux/linkage.h
@@ -69,8 +69,8 @@
#endif
#ifndef __ALIGN
-#define __ALIGN .align 4,0x90
-#define __ALIGN_STR ".align 4,0x90"
+#define __ALIGN .balign CONFIG_FUNCTION_ALIGNMENT
+#define __ALIGN_STR __stringify(__ALIGN)
#endif
#ifdef __ASSEMBLY__
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 3fc7abffc7aa..e90dc6738534 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -467,6 +467,7 @@ config SECTION_MISMATCH_WARN_ONLY
config DEBUG_FORCE_FUNCTION_ALIGN_64B
bool "Force all function address 64B aligned"
depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC)
+ select FUNCTION_ALIGNMENT_64B
help
There are cases that a commit from one domain changes the function
address alignment of other domains, and cause magic performance