5 files changed, 47 insertions, 64 deletions

diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 2d0bd33b73aa..2e1e3af28c3a 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -40,7 +40,7 @@ comment "Page alloc debug is incompatible with Software Suspend on i386"
 
 config DEBUG_PAGEALLOC
         bool "Debug page memory allocations"
-        depends on DEBUG_KERNEL
+        depends on DEBUG_KERNEL && X86_32
         help
           Unmap pages from the kernel linear mapping after free_pages().
           This results in a large slowdown, but helps to find certain types
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 8d7f723cfc28..8ed5c189d7aa 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -781,8 +781,6 @@ void mark_rodata_ro(void)
 
 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 {
-        unsigned long addr;
-
 #ifdef CONFIG_DEBUG_PAGEALLOC
         /*
          * If debugging page accesses then do not free this memory but
@@ -793,6 +791,8 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
                 begin, PAGE_ALIGN(end));
         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
 #else
+        unsigned long addr;
+
         /*
          * We just marked the kernel text read only above, now that
          * we are going to free part of that, we need to make that
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index e0c1e98ad1bf..8a7b725ce3c7 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -569,22 +569,6 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
                 free_page(addr);
                 totalram_pages++;
         }
-#ifdef CONFIG_DEBUG_RODATA
-        /*
-         * This will make the __init pages not present and
-         * not executable, so that any attempt to use a
-         * __init function from now on will fault immediately
-         * rather than supriously later when memory gets reused.
-         *
-         * We only do this for DEBUG_RODATA to not break up the
-         * 2Mb kernel mapping just for this debug feature.
-         */
-        if (begin >= __START_KERNEL_map) {
-                set_memory_rw(begin, (end - begin)/PAGE_SIZE);
-                set_memory_np(begin, (end - begin)/PAGE_SIZE);
-                set_memory_nx(begin, (end - begin)/PAGE_SIZE);
-        }
-#endif
 #endif
 }
 
diff --git a/arch/x86/mm/pageattr-test.c b/arch/x86/mm/pageattr-test.c
index 554820265b95..06353d43f72e 100644
--- a/arch/x86/mm/pageattr-test.c
+++ b/arch/x86/mm/pageattr-test.c
@@ -15,8 +15,7 @@
 #include <asm/kdebug.h>
 
 enum {
-        NTEST                   = 400,
-        LOWEST_LEVEL            = PG_LEVEL_4K,
+        NTEST                   = 4000,
 #ifdef CONFIG_X86_64
         LPS                     = (1 << PMD_SHIFT),
 #elif defined(CONFIG_X86_PAE)
@@ -59,10 +58,10 @@ static __init int print_split(struct split_state *s)
                         continue;
                 }
 
-                if (level == 2 && sizeof(long) == 8) {
+                if (level == PG_LEVEL_1G && sizeof(long) == 8) {
                         s->gpg++;
                         i += GPS/PAGE_SIZE;
-                } else if (level != LOWEST_LEVEL) {
+                } else if (level == PG_LEVEL_2M) {
                         if (!(pte_val(*pte) & _PAGE_PSE)) {
                                 printk(KERN_ERR
                                         "%lx level %d but not PSE %Lx\n",
@@ -162,7 +161,7 @@ static __init int exercise_pageattr(void)
                         continue;
                 }
 
-                err = __change_page_attr_clear(addr[i], len[i],
+                err = change_page_attr_clear(addr[i], len[i],
                                                __pgprot(_PAGE_GLOBAL));
                 if (err < 0) {
                         printk(KERN_ERR "CPA %d failed %d\n", i, err);
@@ -175,7 +174,7 @@ static __init int exercise_pageattr(void)
                                 pte ? (u64)pte_val(*pte) : 0ULL);
                         failed++;
                 }
-                if (level != LOWEST_LEVEL) {
+                if (level != PG_LEVEL_4K) {
                         printk(KERN_ERR "CPA %lx: unexpected level %d\n",
                                 addr[i], level);
                         failed++;
@@ -183,7 +182,6 @@ static __init int exercise_pageattr(void)
 
         }
         vfree(bm);
-        cpa_flush_all();
 
         failed += print_split(&sb);
 
@@ -197,7 +195,7 @@ static __init int exercise_pageattr(void)
                         failed++;
                         continue;
                 }
-                err = __change_page_attr_set(addr[i], len[i],
+                err = change_page_attr_set(addr[i], len[i],
                                              __pgprot(_PAGE_GLOBAL));
                 if (err < 0) {
                         printk(KERN_ERR "CPA reverting failed: %d\n", err);
@@ -211,7 +209,6 @@ static __init int exercise_pageattr(void)
                 }
 
         }
-        cpa_flush_all();
 
         failed += print_split(&sc);
 
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 97ec9e7d29d9..532a40bc0e7e 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -197,10 +197,11 @@ static int split_large_page(pte_t *kpte, unsigned long address)
         unsigned long addr;
         pte_t *pbase, *tmp;
         struct page *base;
-        int i, level;
+        unsigned int i, level;
 
 #ifdef CONFIG_DEBUG_PAGEALLOC
-        gfp_flags = GFP_ATOMIC;
+        gfp_flags = __GFP_HIGH | __GFP_NOFAIL | __GFP_NOWARN;
+        gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
 #endif
         base = alloc_pages(gfp_flags, 0);
         if (!base)
@@ -224,6 +225,7 @@ static int split_large_page(pte_t *kpte, unsigned long address)
         paravirt_alloc_pt(&init_mm, page_to_pfn(base));
 #endif
 
+        pgprot_val(ref_prot) &= ~_PAGE_NX;
         for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE)
                 set_pte(&pbase[i], pfn_pte(addr >> PAGE_SHIFT, ref_prot));
 
@@ -248,7 +250,8 @@ out_unlock:
 }
 
 static int
-__change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot)
+__change_page_attr(unsigned long address, unsigned long pfn,
+                   pgprot_t mask_set, pgprot_t mask_clr)
 {
         struct page *kpte_page;
         int level, err = 0;
@@ -267,15 +270,20 @@ repeat:
         BUG_ON(PageLRU(kpte_page));
         BUG_ON(PageCompound(kpte_page));
 
-        prot = static_protections(prot, address);
-
         if (level == PG_LEVEL_4K) {
-                WARN_ON_ONCE(pgprot_val(prot) & _PAGE_PSE);
-                set_pte_atomic(kpte, pfn_pte(pfn, canon_pgprot(prot)));
-        } else {
-                /* Clear the PSE bit for the 4k level pages ! */
-                pgprot_val(prot) = pgprot_val(prot) & ~_PAGE_PSE;
+                pgprot_t new_prot = pte_pgprot(*kpte);
+                pte_t new_pte, old_pte = *kpte;
+
+                pgprot_val(new_prot) &= ~pgprot_val(mask_clr);
+                pgprot_val(new_prot) |= pgprot_val(mask_set);
+
+                new_prot = static_protections(new_prot, address);
+
+                new_pte = pfn_pte(pfn, canon_pgprot(new_prot));
+                BUG_ON(pte_pfn(new_pte) != pte_pfn(old_pte));
 
+                set_pte_atomic(kpte, new_pte);
+        } else {
                 err = split_large_page(kpte, address);
                 if (!err)
                         goto repeat;
@@ -297,22 +305,26 @@ repeat:
  * Modules and drivers should use the set_memory_* APIs instead.
  */
 
-static int change_page_attr_addr(unsigned long address, pgprot_t prot)
+static int
+change_page_attr_addr(unsigned long address, pgprot_t mask_set,
+                                                        pgprot_t mask_clr)
 {
         int err = 0, kernel_map = 0;
-        unsigned long pfn = __pa(address) >> PAGE_SHIFT;
+        unsigned long pfn;
 
 #ifdef CONFIG_X86_64
         if (address >= __START_KERNEL_map &&
                         address < __START_KERNEL_map + KERNEL_TEXT_SIZE) {
 
-                address = (unsigned long)__va(__pa(address));
+                address = (unsigned long)__va(__pa((void *)address));
                 kernel_map = 1;
         }
 #endif
 
-        if (!kernel_map || pte_present(pfn_pte(0, prot))) {
-                err = __change_page_attr(address, pfn, prot);
+        pfn = __pa(address) >> PAGE_SHIFT;
+
+        if (!kernel_map || 1) {
+                err = __change_page_attr(address, pfn, mask_set, mask_clr);
                 if (err)
                         return err;
         }
@@ -324,12 +336,15 @@ static int change_page_attr_addr(unsigned long address, pgprot_t prot)
          */
         if (__pa(address) < KERNEL_TEXT_SIZE) {
                 unsigned long addr2;
-                pgprot_t prot2;
 
-                addr2 = __START_KERNEL_map + __pa(address);
+                addr2 = __pa(address) + __START_KERNEL_map - phys_base;
                 /* Make sure the kernel mappings stay executable */
-                prot2 = pte_pgprot(pte_mkexec(pfn_pte(0, prot)));
-                err = __change_page_attr(addr2, pfn, prot2);
+                pgprot_val(mask_clr) |= _PAGE_NX;
+                /*
+                 * Our high aliases are imprecise, so do not propagate
+                 * failures back to users:
+                 */
+                __change_page_attr(addr2, pfn, mask_set, mask_clr);
         }
 #endif
 
@@ -339,26 +354,13 @@ static int change_page_attr_addr(unsigned long address, pgprot_t prot)
 static int __change_page_attr_set_clr(unsigned long addr, int numpages,
                                       pgprot_t mask_set, pgprot_t mask_clr)
 {
-        pgprot_t new_prot;
-        int level;
-        pte_t *pte;
-        int i, ret;
-
-        for (i = 0; i < numpages ; i++) {
-
-                pte = lookup_address(addr, &level);
-                if (!pte)
-                        return -EINVAL;
-
-                new_prot = pte_pgprot(*pte);
-
-                pgprot_val(new_prot) &= ~pgprot_val(mask_clr);
-                pgprot_val(new_prot) |= pgprot_val(mask_set);
+        unsigned int i;
+        int ret;
 
-                ret = change_page_attr_addr(addr, new_prot);
+        for (i = 0; i < numpages ; i++, addr += PAGE_SIZE) {
+                ret = change_page_attr_addr(addr, mask_set, mask_clr);
                 if (ret)
                         return ret;
-                addr += PAGE_SIZE;
         }
 
         return 0;