Merge branch 'rfc/splice/tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux...

[linux-2.6-omap-h63xx.git] / arch / x86 / mm / init_32.c

diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 88f1b10de3be712a33545b20292a45f7a1c43c50..3eb2ed188a4cbb85cb0b1adceeceb85541a9d177 100644 (file)
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -138,6 +138,47 @@ static pte_t * __init one_page_table_init(pmd_t *pmd)
        return pte_offset_kernel(pmd, 0);
 }
 
+static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
+                                          unsigned long vaddr, pte_t *lastpte)
+{
+#ifdef CONFIG_HIGHMEM
+       /*
+        * Something (early fixmap) may already have put a pte
+        * page here, which causes the page table allocation
+        * to become nonlinear. Attempt to fix it, and if it
+        * is still nonlinear then we have to bug.
+        */
+       int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
+       int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
+
+       if (pmd_idx_kmap_begin != pmd_idx_kmap_end
+           && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin
+           && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end
+           && ((__pa(pte) >> PAGE_SHIFT) < table_start
+               || (__pa(pte) >> PAGE_SHIFT) >= table_end)) {
+               pte_t *newpte;
+               int i;
+
+               BUG_ON(after_init_bootmem);
+               newpte = alloc_low_page();
+               for (i = 0; i < PTRS_PER_PTE; i++)
+                       set_pte(newpte + i, pte[i]);
+
+               paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT);
+               set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE));
+               BUG_ON(newpte != pte_offset_kernel(pmd, 0));
+               __flush_tlb_all();
+
+               paravirt_release_pte(__pa(pte) >> PAGE_SHIFT);
+               pte = newpte;
+       }
+       BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1)
+              && vaddr > fix_to_virt(FIX_KMAP_END)
+              && lastpte && lastpte + PTRS_PER_PTE != pte);
+#endif
+       return pte;
+}
+
 /*
  * This function initializes a certain range of kernel virtual memory
  * with new bootmem page tables, everywhere page tables are missing in
@@ -154,6 +195,7 @@ page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
        unsigned long vaddr;
        pgd_t *pgd;
        pmd_t *pmd;
+       pte_t *pte = NULL;
 
        vaddr = start;
        pgd_idx = pgd_index(vaddr);
@@ -165,7 +207,8 @@ page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
                pmd = pmd + pmd_index(vaddr);
                for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
                                                        pmd++, pmd_idx++) {
-                       one_page_table_init(pmd);
+                       pte = page_table_kmap_check(one_page_table_init(pmd),
+                                                   pmd, vaddr, pte);
 
                        vaddr += PMD_SIZE;
                }
@@ -508,7 +551,6 @@ static void __init early_ioremap_page_table_range_init(pgd_t *pgd_base)
         * Fixed mappings, only the page table structure has to be
         * created - mappings will be set by set_fixmap():
         */
-       early_ioremap_clear();
        vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
        end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
        page_table_range_init(vaddr, end, pgd_base);
@@ -801,7 +843,7 @@ static void __init find_early_table_space(unsigned long end, int use_pse)
        tables += PAGE_ALIGN(ptes * sizeof(pte_t));
 
        /* for fixmap */
-       tables += PAGE_SIZE * 2;
+       tables += PAGE_ALIGN(__end_of_fixed_addresses * sizeof(pte_t));
 
        /*
         * RED-PEN putting page tables only on node 0 could
@@ -1113,17 +1155,47 @@ static noinline int do_test_wp_bit(void)
 const int rodata_test_data = 0xC3;
 EXPORT_SYMBOL_GPL(rodata_test_data);
 
+static int kernel_set_to_readonly;
+
+void set_kernel_text_rw(void)
+{
+       unsigned long start = PFN_ALIGN(_text);
+       unsigned long size = PFN_ALIGN(_etext) - start;
+
+       if (!kernel_set_to_readonly)
+               return;
+
+       pr_debug("Set kernel text: %lx - %lx for read write\n",
+                start, start+size);
+
+       set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
+}
+
+void set_kernel_text_ro(void)
+{
+       unsigned long start = PFN_ALIGN(_text);
+       unsigned long size = PFN_ALIGN(_etext) - start;
+
+       if (!kernel_set_to_readonly)
+               return;
+
+       pr_debug("Set kernel text: %lx - %lx for read only\n",
+                start, start+size);
+
+       set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
+}
+
 void mark_rodata_ro(void)
 {
        unsigned long start = PFN_ALIGN(_text);
        unsigned long size = PFN_ALIGN(_etext) - start;
 
-#ifndef CONFIG_DYNAMIC_FTRACE
-       /* Dynamic tracing modifies the kernel text section */
        set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
        printk(KERN_INFO "Write protecting the kernel text: %luk\n",
                size >> 10);
 
+       kernel_set_to_readonly = 1;
+
 #ifdef CONFIG_CPA_DEBUG
        printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
                start, start+size);
@@ -1132,7 +1204,6 @@ void mark_rodata_ro(void)
        printk(KERN_INFO "Testing CPA: write protecting again\n");
        set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
 #endif
-#endif /* CONFIG_DYNAMIC_FTRACE */
 
        start += size;
        size = (unsigned long)__end_rodata - start;