s390/kasan: use set_pXe_bit() for pgtable entries setup

Convert setup of pgtable entries to use set_pXe_bit()
helpers as the preferred way in MM code.

Locally introduce pgprot_clear_bit() helper, which is
strictly speaking a generic function. However, it is
only x86 pgprot_clear_protnone_bits() helper, which
does a similar thing, so do not make it public.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

diff --git a/arch/s390/mm/kasan_init.c b/arch/s390/mm/kasan_init.c
index 89545280935a4f073965e22e716e8b6fb3ca701f..a97b7981358ec14387c21d2192bac181510ee1f2 100644 (file)
--- a/arch/s390/mm/kasan_init.c
+++ b/arch/s390/mm/kasan_init.c
@@ -86,25 +86,32 @@ enum populate_mode {
        POPULATE_ZERO_SHADOW,
        POPULATE_SHALLOW
 };
+
+static inline pgprot_t pgprot_clear_bit(pgprot_t pgprot, unsigned long bit)
+{
+       return __pgprot(pgprot_val(pgprot) & ~bit);
+}
+
 static void __init kasan_early_pgtable_populate(unsigned long address,
                                                unsigned long end,
                                                enum populate_mode mode)
 {
-       unsigned long pgt_prot_zero, pgt_prot, sgt_prot;
+       pgprot_t pgt_prot_zero = PAGE_KERNEL_RO;
+       pgprot_t pgt_prot = PAGE_KERNEL;
+       pgprot_t sgt_prot = SEGMENT_KERNEL;
        pgd_t *pg_dir;
        p4d_t *p4_dir;
        pud_t *pu_dir;
        pmd_t *pm_dir;
        pte_t *pt_dir;
+       pmd_t pmd;
+       pte_t pte;
 
-       pgt_prot_zero = pgprot_val(PAGE_KERNEL_RO);
        if (!has_nx)
-               pgt_prot_zero &= ~_PAGE_NOEXEC;
-       pgt_prot = pgprot_val(PAGE_KERNEL);
-       sgt_prot = pgprot_val(SEGMENT_KERNEL);
+               pgt_prot_zero = pgprot_clear_bit(pgt_prot_zero, _PAGE_NOEXEC);
        if (!has_nx || mode == POPULATE_ONE2ONE) {
-               pgt_prot &= ~_PAGE_NOEXEC;
-               sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;
+               pgt_prot = pgprot_clear_bit(pgt_prot, _PAGE_NOEXEC);
+               sgt_prot = pgprot_clear_bit(sgt_prot, _SEGMENT_ENTRY_NOEXEC);
        }
 
        /*
@@ -175,7 +182,9 @@ static void __init kasan_early_pgtable_populate(unsigned long address,
                                                page = kasan_early_alloc_segment();
                                                memset(page, 0, _SEGMENT_SIZE);
                                        }
-                                       set_pmd(pm_dir, __pmd(__pa(page) | sgt_prot));
+                                       pmd = __pmd(__pa(page));
+                                       pmd = set_pmd_bit(pmd, sgt_prot);
+                                       set_pmd(pm_dir, pmd);
                                        address = (address + PMD_SIZE) & PMD_MASK;
                                        continue;
                                }
@@ -194,16 +203,22 @@ static void __init kasan_early_pgtable_populate(unsigned long address,
                        switch (mode) {
                        case POPULATE_ONE2ONE:
                                page = (void *)address;
-                               set_pte(pt_dir, __pte(__pa(page) | pgt_prot));
+                               pte = __pte(__pa(page));
+                               pte = set_pte_bit(pte, pgt_prot);
+                               set_pte(pt_dir, pte);
                                break;
                        case POPULATE_MAP:
                                page = kasan_early_alloc_pages(0);
                                memset(page, 0, PAGE_SIZE);
-                               set_pte(pt_dir, __pte(__pa(page) | pgt_prot));
+                               pte = __pte(__pa(page));
+                               pte = set_pte_bit(pte, pgt_prot);
+                               set_pte(pt_dir, pte);
                                break;
                        case POPULATE_ZERO_SHADOW:
                                page = kasan_early_shadow_page;
-                               set_pte(pt_dir, __pte(__pa(page) | pgt_prot_zero));
+                               pte = __pte(__pa(page));
+                               pte = set_pte_bit(pte, pgt_prot_zero);
+                               set_pte(pt_dir, pte);
                                break;
                        case POPULATE_SHALLOW:
                                /* should never happen */