Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg...

[pandora-kernel.git] / arch / x86 / mm / pageattr.c

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 532e793..8b830ca 100644 (file)
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -13,6 +13,7 @@
 #include <linux/pfn.h>
 #include <linux/percpu.h>
 #include <linux/gfp.h>
+#include <linux/pci.h>
 
 #include <asm/e820.h>
 #include <asm/processor.h>
@@ -255,13 +256,16 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address,
                                   unsigned long pfn)
 {
        pgprot_t forbidden = __pgprot(0);
+       pgprot_t required = __pgprot(0);
 
        /*
         * The BIOS area between 640k and 1Mb needs to be executable for
         * PCI BIOS based config access (CONFIG_PCI_GOBIOS) support.
         */
-       if (within(pfn, BIOS_BEGIN >> PAGE_SHIFT, BIOS_END >> PAGE_SHIFT))
+#ifdef CONFIG_PCI_BIOS
+       if (pcibios_enabled && within(pfn, BIOS_BEGIN >> PAGE_SHIFT, BIOS_END >> PAGE_SHIFT))
                pgprot_val(forbidden) |= _PAGE_NX;
+#endif
 
        /*
         * The kernel text needs to be executable for obvious reasons
@@ -278,6 +282,12 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address,
        if (within(pfn, __pa((unsigned long)__start_rodata) >> PAGE_SHIFT,
                   __pa((unsigned long)__end_rodata) >> PAGE_SHIFT))
                pgprot_val(forbidden) |= _PAGE_RW;
+       /*
+        * .data and .bss should always be writable.
+        */
+       if (within(address, (unsigned long)_sdata, (unsigned long)_edata) ||
+           within(address, (unsigned long)__bss_start, (unsigned long)__bss_stop))
+               pgprot_val(required) |= _PAGE_RW;
 
 #if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA)
        /*
@@ -317,6 +327,7 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address,
 #endif
 
        prot = __pgprot(pgprot_val(prot) & ~pgprot_val(forbidden));
+       prot = __pgprot(pgprot_val(prot) | pgprot_val(required));
 
        return prot;
 }
@@ -393,7 +404,7 @@ try_preserve_large_page(pte_t *kpte, unsigned long address,
 {
        unsigned long nextpage_addr, numpages, pmask, psize, flags, addr, pfn;
        pte_t new_pte, old_pte, *tmp;
-       pgprot_t old_prot, new_prot;
+       pgprot_t old_prot, new_prot, req_prot;
        int i, do_split = 1;
        unsigned int level;
 
@@ -438,10 +449,10 @@ try_preserve_large_page(pte_t *kpte, unsigned long address,
         * We are safe now. Check whether the new pgprot is the same:
         */
        old_pte = *kpte;
-       old_prot = new_prot = pte_pgprot(old_pte);
+       old_prot = new_prot = req_prot = pte_pgprot(old_pte);
 
-       pgprot_val(new_prot) &= ~pgprot_val(cpa->mask_clr);
-       pgprot_val(new_prot) |= pgprot_val(cpa->mask_set);
+       pgprot_val(req_prot) &= ~pgprot_val(cpa->mask_clr);
+       pgprot_val(req_prot) |= pgprot_val(cpa->mask_set);
 
        /*
         * old_pte points to the large page base address. So we need
@@ -450,17 +461,17 @@ try_preserve_large_page(pte_t *kpte, unsigned long address,
        pfn = pte_pfn(old_pte) + ((address & (psize - 1)) >> PAGE_SHIFT);
        cpa->pfn = pfn;
 
-       new_prot = static_protections(new_prot, address, pfn);
+       new_prot = static_protections(req_prot, address, pfn);
 
        /*
         * We need to check the full range, whether
         * static_protection() requires a different pgprot for one of
         * the pages in the range we try to preserve:
         */
-       addr = address + PAGE_SIZE;
-       pfn++;
-       for (i = 1; i < cpa->numpages; i++, addr += PAGE_SIZE, pfn++) {
-               pgprot_t chk_prot = static_protections(new_prot, addr, pfn);
+       addr = address & pmask;
+       pfn = pte_pfn(old_pte);
+       for (i = 0; i < (psize >> PAGE_SHIFT); i++, addr += PAGE_SIZE, pfn++) {
+               pgprot_t chk_prot = static_protections(req_prot, addr, pfn);
 
                if (pgprot_val(chk_prot) != pgprot_val(new_prot))
                        goto out_unlock;
@@ -483,7 +494,7 @@ try_preserve_large_page(pte_t *kpte, unsigned long address,
         * that we limited the number of possible pages already to
         * the number of pages in the large page.
         */
-       if (address == (nextpage_addr - psize) && cpa->numpages == numpages) {
+       if (address == (address & pmask) && cpa->numpages == (psize >> PAGE_SHIFT)) {
                /*
                 * The address is aligned and the number of pages
                 * covers the full page.