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Diffstat (limited to 'arch/s390/mm/pageattr.c')
-rw-r--r--arch/s390/mm/pageattr.c40
1 files changed, 25 insertions, 15 deletions
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index b36537a5f43e..00be01c4b4f3 100644
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -8,25 +8,38 @@
#include <asm/cacheflush.h>
#include <asm/pgtable.h>
+static pte_t *walk_page_table(unsigned long addr)
+{
+ pgd_t *pgdp;
+ pud_t *pudp;
+ pmd_t *pmdp;
+ pte_t *ptep;
+
+ pgdp = pgd_offset_k(addr);
+ if (pgd_none(*pgdp))
+ return NULL;
+ pudp = pud_offset(pgdp, addr);
+ if (pud_none(*pudp))
+ return NULL;
+ pmdp = pmd_offset(pudp, addr);
+ if (pmd_none(*pmdp) || pmd_large(*pmdp))
+ return NULL;
+ ptep = pte_offset_kernel(pmdp, addr);
+ if (pte_none(*ptep))
+ return NULL;
+ return ptep;
+}
+
static void change_page_attr(unsigned long addr, int numpages,
pte_t (*set) (pte_t))
{
pte_t *ptep, pte;
- pmd_t *pmdp;
- pud_t *pudp;
- pgd_t *pgdp;
int i;
for (i = 0; i < numpages; i++) {
- pgdp = pgd_offset(&init_mm, addr);
- pudp = pud_offset(pgdp, addr);
- pmdp = pmd_offset(pudp, addr);
- if (pmd_huge(*pmdp)) {
- WARN_ON_ONCE(1);
- continue;
- }
- ptep = pte_offset_kernel(pmdp, addr);
-
+ ptep = walk_page_table(addr);
+ if (WARN_ON_ONCE(!ptep))
+ break;
pte = *ptep;
pte = set(pte);
__ptep_ipte(addr, ptep);
@@ -40,21 +53,18 @@ int set_memory_ro(unsigned long addr, int numpages)
change_page_attr(addr, numpages, pte_wrprotect);
return 0;
}
-EXPORT_SYMBOL_GPL(set_memory_ro);
int set_memory_rw(unsigned long addr, int numpages)
{
change_page_attr(addr, numpages, pte_mkwrite);
return 0;
}
-EXPORT_SYMBOL_GPL(set_memory_rw);
/* not possible */
int set_memory_nx(unsigned long addr, int numpages)
{
return 0;
}
-EXPORT_SYMBOL_GPL(set_memory_nx);
int set_memory_x(unsigned long addr, int numpages)
{