Ok, the use of "1 + " and subtraction of one for PAE PDPEs has confused
many people now.  Make it explicit what is going on and why anding with
PAGE_MASK is a better idea to strip these bits.

Signed-off-by: Zachary Amsden <[EMAIL PROTECTED]>
Depends-on: add-pgtable-allocation-notifiers
Index: linux-2.6.13/arch/i386/mm/pgtable.c
===================================================================
--- linux-2.6.13.orig/arch/i386/mm/pgtable.c    2005-08-31 14:48:17.000000000 
-0700
+++ linux-2.6.13/arch/i386/mm/pgtable.c 2005-08-31 14:48:53.000000000 -0700
@@ -247,14 +247,14 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
                if (!pmd)
                        goto out_oom;
                SetPagePDE(virt_to_page(pmd));
-               set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
+               set_pgd(&pgd[i], __pgd(_PAGE_PRESENT | __pa(pmd)));
        }
        return pgd;
 
 out_oom:
        for (i--; i >= 0; i--) {
                ClearPagePDE(pfn_to_page(pgd_val(pgd[i]) >> PAGE_SHIFT));
-               kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
+               kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i]) & 
PAGE_MASK));
        }
        kmem_cache_free(pgd_cache, pgd);
        return NULL;
@@ -268,7 +268,7 @@ void pgd_free(pgd_t *pgd)
        if (PTRS_PER_PMD > 1)
                for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
                        ClearPagePDE(pfn_to_page(pgd_val(pgd[i]) >> 
PAGE_SHIFT));
-                       kmem_cache_free(pmd_cache, (void 
*)__va(pgd_val(pgd[i])-1));
+                       kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i]) 
& PAGE_MASK));
                }
        /* in the non-PAE case, free_pgtables() clears user pgd entries */
        kmem_cache_free(pgd_cache, pgd);
Index: linux-2.6.13/arch/i386/mm/init.c
===================================================================
--- linux-2.6.13.orig/arch/i386/mm/init.c       2005-08-31 14:48:17.000000000 
-0700
+++ linux-2.6.13/arch/i386/mm/init.c    2005-08-31 14:48:53.000000000 -0700
@@ -387,7 +387,7 @@ void zap_low_mappings (void)
         */
        for (i = 0; i < USER_PTRS_PER_PGD; i++)
 #ifdef CONFIG_X86_PAE
-               set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page)));
+               set_pgd(swapper_pg_dir+i, __pgd(_PAGE_PRESENT | 
__pa(empty_zero_page)));
 #else
                set_pgd(swapper_pg_dir+i, __pgd(0));
 #endif
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to