[PATCH/RFC 3/5] make rodata section read-only again

[Heiko Carstens <heiko.carstens@de.ibm.com>]

Make sure the rodata section is read only again.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
---
 arch/s390/mm/init.c |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+)

Index: linux-2.6.19-rc6-mm2/arch/s390/mm/init.c
===================================================================
--- linux-2.6.19-rc6-mm2.orig/arch/s390/mm/init.c
+++ linux-2.6.19-rc6-mm2/arch/s390/mm/init.c
@@ -84,6 +84,26 @@ void show_mem(void)
         printk("%d pages swap cached\n",cached);
 }
 
+static __init void setup_ro_region(void)
+{
+	pgd_t *pgd;
+	pmd_t *pmd;
+	pte_t *pte;
+	pte_t new_pte;
+	unsigned long address, end;
+
+	address = ((unsigned long)&__start_rodata) & PAGE_MASK;
+	end = PFN_ALIGN((unsigned long)&__end_rodata);
+
+	for (; address < end; address += PAGE_SIZE) {
+		pgd = pgd_offset_k(address);
+		pmd = pmd_offset(pgd, address);
+		pte = pte_offset_kernel(pmd, address);
+		new_pte = mk_pte_phys(address, __pgprot(_PAGE_RO));
+		set_pte(pte, new_pte);
+	}
+}
+
 extern unsigned long __initdata zholes_size[];
 extern void vmem_map_init(void);
 /*
@@ -110,6 +130,7 @@ void __init paging_init(void)
 		pmd_clear((pmd_t *)(pg_dir + i));
 #endif
 	vmem_map_init();
+	setup_ro_region();
 
 	S390_lowcore.kernel_asce = pgdir_k;
 

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