x86: move tracedata to RODATA

.. allowing it to be write-protected just as other read-only data
under CONFIG_DEBUG_RODATA.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/vmlinux_32.lds.S

@@ -60,13 +60,6 @@ SECTIONS
 
   BUG_TABLE :text
 
-  . = ALIGN(4);
-  .tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) {
-  	__tracedata_start = .;
-	*(.tracedata)
-  	__tracedata_end = .;
-  }
-
   RODATA
 
   /* writeable */

arch/x86/kernel/vmlinux_64.lds.S

@@ -53,13 +53,6 @@ SECTIONS
 
   RODATA
 
-  . = ALIGN(4);
-  .tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) {
-  	__tracedata_start = .;
-	*(.tracedata)
-  	__tracedata_end = .;
-  }
-
   . = ALIGN(PAGE_SIZE);		/* Align data segment to page size boundary */
 				/* Data */
   .data : AT(ADDR(.data) - LOAD_OFFSET) {

drivers/base/power/trace.c

@@ -153,7 +153,7 @@ EXPORT_SYMBOL(set_trace_device);
  * it's not any guarantee, but it's a high _likelihood_ that
  * the match is valid).
  */
-void generate_resume_trace(void *tracedata, unsigned int user)
+void generate_resume_trace(const void *tracedata, unsigned int user)
 {
 	unsigned short lineno = *(unsigned short *)tracedata;
 	const char *file = *(const char **)(tracedata + 2);

include/asm-generic/vmlinux.lds.h

@@ -93,6 +93,8 @@
 		VMLINUX_SYMBOL(__end_rio_route_ops) = .;		\
 	}								\
 									\
+	TRACEDATA							\
+									\
 	/* Kernel symbol table: Normal symbols */			\
 	__ksymtab         : AT(ADDR(__ksymtab) - LOAD_OFFSET) {		\
 		VMLINUX_SYMBOL(__start___ksymtab) = .;			\
@@ -318,6 +320,18 @@
 		__stop___bug_table = .;					\
 	}
 
+#ifdef CONFIG_PM_TRACE
+#define TRACEDATA							\
+	. = ALIGN(4);							\
+	.tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) {		\
+	  	__tracedata_start = .;					\
+		*(.tracedata)						\
+	  	__tracedata_end = .;					\
+	}
+#else
+#define TRACEDATA
+#endif
+
 #define NOTES								\
 	.notes : AT(ADDR(.notes) - LOAD_OFFSET) {			\
 		VMLINUX_SYMBOL(__start_notes) = .;			\

include/asm-x86/resume-trace.h

@@ -6,7 +6,7 @@
 #define TRACE_RESUME(user)					\
 do {								\
 	if (pm_trace_enabled) {					\
-		void *tracedata;				\
+		const void *tracedata;				\
 		asm volatile(_ASM_MOV_UL " $1f,%0\n"		\
 			     ".section .tracedata,\"a\"\n"	\
 			     "1:\t.word %c1\n\t"		\

include/linux/resume-trace.h

@@ -8,7 +8,7 @@ extern int pm_trace_enabled;
 
 struct device;
 extern void set_trace_device(struct device *);
-extern void generate_resume_trace(void *tracedata, unsigned int user);
+extern void generate_resume_trace(const void *tracedata, unsigned int user);
 
 #define TRACE_DEVICE(dev) do { \
 	if (pm_trace_enabled) \