[PATCH] xen/ppc: Ensure ELF sections' physical load addresses start at 0x0

[Shawn Anastasio <sanastasio@raptorengineering.com>]

Some boot mechanisms, including the new linux file_load kexec systemcall
used by system firmware v2.10 on RaptorCS systems will try to honor the
physical address field of the ELF LOAD section header, which will fail
when the address is based off of XEN_VIRT_START (0xc000000000000000).

To ensure that the physical address of the LOAD section header starts at
0x0, import the DECL_SECTION macro from x86's xen.lds.S.

Signed-off-by: Shawn Anastasio <sanastasio@raptorengineering.com>
---
 xen/arch/ppc/xen.lds.S | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/xen/arch/ppc/xen.lds.S b/xen/arch/ppc/xen.lds.S
index 05b6db2728..0ed285f0a7 100644
--- a/xen/arch/ppc/xen.lds.S
+++ b/xen/arch/ppc/xen.lds.S
@@ -4,6 +4,12 @@
 OUTPUT_ARCH(powerpc:common64)
 ENTRY(start)
 
+#ifdef CONFIG_LD_IS_GNU
+# define DECL_SECTION(x) x : AT(ADDR(#x) - XEN_VIRT_START)
+#else
+# define DECL_SECTION(x) x : AT(ADDR(x) - XEN_VIRT_START)
+#endif
+
 PHDRS
 {
     text PT_LOAD ;
@@ -17,7 +23,7 @@ SECTIONS
     . = XEN_VIRT_START;
     _start = .;
 
-    .text : {
+    DECL_SECTION(.text) {
         _stext = .;            /* Text section */
         *(.text.header)
 
@@ -40,7 +46,7 @@ SECTIONS
     } :text
 
     . = ALIGN(PAGE_SIZE);
-    .rodata : {
+    DECL_SECTION(.rodata) {
         _srodata = .;          /* Read-only data */
         /* Bug frames table */
         __start_bug_frames = .;
@@ -64,7 +70,7 @@ SECTIONS
 
     #if defined(BUILD_ID)
     . = ALIGN(4);
-    .note.gnu.build-id : {
+    DECL_SECTION(.note.gnu.build-id) {
         __note_gnu_build_id_start = .;
         *(.note.gnu.build-id)
         __note_gnu_build_id_end = .;
@@ -73,19 +79,19 @@ SECTIONS
     _erodata = .;                /* End of read-only data */
 
     . = ALIGN(PAGE_SIZE);
-    .data.ro_after_init : {
+    DECL_SECTION(.data.ro_after_init) {
         __ro_after_init_start = .;
         *(.data.ro_after_init)
         . = ALIGN(PAGE_SIZE);
         __ro_after_init_end = .;
     } :text
 
-    .data.read_mostly : {
+    DECL_SECTION(.data.read_mostly) {
         *(.data.read_mostly)
     } :text
 
     . = ALIGN(PAGE_SIZE);
-    .data : {                    /* Data */
+    DECL_SECTION(.data) {                    /* Data */
         *(.data.page_aligned)
         . = ALIGN(8);
         __start_schedulers_array = .;
@@ -100,7 +106,7 @@ SECTIONS
 
     . = ALIGN(PAGE_SIZE);             /* Init code and data */
     __init_begin = .;
-    .init.text : {
+    DECL_SECTION(.init.text) {
         _sinittext = .;
         *(.init.text)
         _einittext = .;
@@ -108,7 +114,7 @@ SECTIONS
     } :text
 
     . = ALIGN(PAGE_SIZE);
-    .init.data : {
+    DECL_SECTION(init.data) {
         *(.init.rodata)
         *(.init.rodata.*)
 
@@ -137,18 +143,18 @@ SECTIONS
         __ctors_end = .;
     } :text
 
-    .got : {
+    DECL_SECTION(.got) {
         *(.got .toc)
     } :text
 
-    .got.plt : {
+    DECL_SECTION(.got.plt) {
         *(.got.plt)
     } :text
 
     . = ALIGN(POINTER_ALIGN);
     __init_end = .;
 
-    .bss : {                     /* BSS */
+    DECL_SECTION(.bss) {                     /* BSS */
         __bss_start = .;
         *(.bss.stack_aligned)
         *(.bss.page_aligned)
@@ -168,7 +174,7 @@ SECTIONS
     _end = . ;
 
     /* Section for the device tree blob (if any). */
-    .dtb : { *(.dtb) } :text
+    DECL_SECTION(.dtb) { *(.dtb) } :text
 
     DWARF2_DEBUG_SECTIONS
 
-- 
2.30.2