[S390] Mark kernel text section read-only.

Set read-only flag in the page table entries for the kernel image text
section. This will catch all instruction caused corruptions withing the
text section.
Instruction replacement via kprobes still works, since it bypasses now
dynamic address translation.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 4 insertions, 5 deletions

diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 162a338a5575..b3e7c45efb63 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -26,7 +26,6 @@
 #include <linux/pfn.h>
 #include <linux/poison.h>
 #include <linux/initrd.h>
-
 #include <asm/processor.h>
 #include <asm/system.h>
 #include <asm/uaccess.h>
@@ -96,8 +95,8 @@ static void __init setup_ro_region(void)
         pte_t new_pte;
         unsigned long address, end;
 
-        address = ((unsigned long)&__start_rodata) & PAGE_MASK;
-        end = PFN_ALIGN((unsigned long)&__end_rodata);
+        address = ((unsigned long)&_stext) & PAGE_MASK;
+        end = PFN_ALIGN((unsigned long)&_eshared);
 
         for (; address < end; address += PAGE_SIZE) {
                 pgd = pgd_offset_k(address);
@@ -173,8 +172,8 @@ void __init mem_init(void)
                 datasize >>10,
                 initsize >> 10);
         printk("Write protected kernel read-only data: %#lx - %#lx\n",
-               (unsigned long)&__start_rodata,
-               PFN_ALIGN((unsigned long)&__end_rodata) - 1);
+               (unsigned long)&_stext,
+               PFN_ALIGN((unsigned long)&_eshared) - 1);
 }
 
 void free_initmem(void)