Merge branch 'v4.4/topic/ro-vdso' into linux-linaro-lsk-v4.4

Author: Alex Shi

arch/s390/Kconfig

@@ -62,6 +62,9 @@ config PCI_QUIRKS
 config ARCH_SUPPORTS_UPROBES
 	def_bool y
 
+config DEBUG_RODATA
+	def_bool y
+
 config S390
 	def_bool y
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE

arch/s390/mm/init.c

@@ -109,6 +109,13 @@ void __init paging_init(void)
 	free_area_init_nodes(max_zone_pfns);
 }
 
+void mark_rodata_ro(void)
+{
+	/* Text and rodata are already protected. Nothing to do here. */
+	pr_info("Write protecting the kernel read-only data: %luk\n",
+		((unsigned long)&_eshared - (unsigned long)&_stext) >> 10);
+}
+
 void __init mem_init(void)
 {
 	if (MACHINE_HAS_TLB_LC)
@@ -127,9 +134,6 @@ void __init mem_init(void)
 	setup_zero_pages();	/* Setup zeroed pages. */
 
 	mem_init_print_info(NULL);
-	printk("Write protected kernel read-only data: %#lx - %#lx\n",
-	       (unsigned long)&_stext,
-	       PFN_ALIGN((unsigned long)&_eshared) - 1);
 }
 
 void free_initmem(void)

include/asm-generic/vmlinux.lds.h

@@ -248,6 +248,14 @@
 	. = ALIGN(align);						\
 	*(.data..init_task)
 
+/*
+ * Allow architectures to handle ro_after_init data on their
+ * own by defining an empty RO_AFTER_INIT_DATA.
+ */
+#ifndef RO_AFTER_INIT_DATA
+#define RO_AFTER_INIT_DATA *(.data..ro_after_init)
+#endif
+
 /*
  * Read only Data
  */
@@ -256,7 +264,7 @@
 	.rodata           : AT(ADDR(.rodata) - LOAD_OFFSET) {		\
 		VMLINUX_SYMBOL(__start_rodata) = .;			\
 		*(.rodata) *(.rodata.*)					\
-		*(.data..ro_after_init)	/* Read only after init */	\
+		RO_AFTER_INIT_DATA	/* Read only after init */	\
 		*(__vermagic)		/* Kernel version magic */	\
 		. = ALIGN(8);						\
 		VMLINUX_SYMBOL(__start___tracepoints_ptrs) = .;		\