diff options
Diffstat (limited to 'arch/s390/mm/pageattr.c')
| -rw-r--r-- | arch/s390/mm/pageattr.c | 40 |
1 files changed, 25 insertions, 15 deletions
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c index b36537a5f43..00be01c4b4f 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) { |