[PATCH] powerpc: Add support for BUILD_SALT in kernel, modules & VDSO

[Michael Ellerman]

This patch adds support for BUILD_SALT in the kernel, modules and
VDSO. See the commit that adds BUILD_SALT for more info.

Kernel:
  0:mon> d c000000001340840
  c000000001340840 0055aaff12345678 1234567812345678  |.U...4Vx.4Vx.4Vx|
  c000000001340850 1234567812345678 1234567812345678  |.4Vx.4Vx.4Vx.4Vx|

Module:

  $ cat/sys/module/kvm/sections/.salt
  0xd0000000064385e8
  ...
  0:mon> d d0000000064385e8
  d0000000064385e8 0055aaff12345678 1234567812345678  |.U...4Vx.4Vx.4Vx|
  d0000000064385f8 1234567812345678 1234567812345678  |.4Vx.4Vx.4Vx.4Vx|

vdso:
  (gdb) x/4xw (0x7ffff7f80000 + 0x4a0)
  0x7ffff7f804a0:	0xffaa5500	0x78563412	0x78563412	0x78563412

Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
---
 arch/powerpc/kernel/vdso32/vdso32.lds.S | 2 ++
 arch/powerpc/kernel/vdso64/vdso64.lds.S | 2 ++
 arch/powerpc/kernel/vmlinux.lds.S       | 1 +
 3 files changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/vdso32/vdso32.lds.S b/arch/powerpc/kernel/vdso32/vdso32.lds.S
index 099a6db14e67..c06a12607777 100644
--- a/arch/powerpc/kernel/vdso32/vdso32.lds.S
+++ b/arch/powerpc/kernel/vdso32/vdso32.lds.S
@@ -4,6 +4,7 @@
  * library
  */
 #include <asm/vdso.h>
+#include <asm-generic/vmlinux.lds.h>
 
 #ifdef __LITTLE_ENDIAN__
 OUTPUT_FORMAT("elf32-powerpcle", "elf32-powerpcle", "elf32-powerpcle")
@@ -25,6 +26,7 @@ SECTIONS
 	.gnu.version_d 	: { *(.gnu.version_d) }
 	.gnu.version_r 	: { *(.gnu.version_r) }
 
+	BUILD_SALT
 	.note		: { *(.note.*) }		:text	:note
 
 	. = ALIGN(16);
diff --git a/arch/powerpc/kernel/vdso64/vdso64.lds.S b/arch/powerpc/kernel/vdso64/vdso64.lds.S
index 256fb9720298..ace69258446a 100644
--- a/arch/powerpc/kernel/vdso64/vdso64.lds.S
+++ b/arch/powerpc/kernel/vdso64/vdso64.lds.S
@@ -4,6 +4,7 @@
  * library
  */
 #include <asm/vdso.h>
+#include <asm-generic/vmlinux.lds.h>
 
 #ifdef __LITTLE_ENDIAN__
 OUTPUT_FORMAT("elf64-powerpcle", "elf64-powerpcle", "elf64-powerpcle")
@@ -25,6 +26,7 @@ SECTIONS
 	.gnu.version_d	: { *(.gnu.version_d) }
 	.gnu.version_r	: { *(.gnu.version_r) }
 
+	BUILD_SALT
 	.note		: { *(.note.*) }		:text	:note
 
 	. = ALIGN(16);
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 5baac79df97e..59635369ceea 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -348,6 +348,7 @@ SECTIONS
 	}
 
 	BUG_TABLE
+	BUILD_SALT
 
 	. = ALIGN(PAGE_SIZE);
 	_edata  =  .;
-- 
2.14.1