X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=arch%2Fx86%2Fmm%2Fpageattr.c;h=8b830ca14ac46c08facc1a848ddcb3c42c0d56cf;hb=a1e8fad5900fa94adb500c6e0dfd60a307f7a3c9;hp=532e7933d606fdbdde77aacdb2de746f249d2bf2;hpb=a9ad99a612763803b995ce551ca43b20beb1f888;p=pandora-kernel.git

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 532e7933d606..8b830ca14ac4 100644
--- 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.