MIPS: Remove race window in page fault handling

[cascardo/linux.git] / arch / mips / mm / cache.c

diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c
index f7b91d3..7e3ea77 100644 (file)
--- a/arch/mips/mm/cache.c
+++ b/arch/mips/mm/cache.c
@@ -119,25 +119,36 @@ void __flush_anon_page(struct page *page, unsigned long vmaddr)
 
 EXPORT_SYMBOL(__flush_anon_page);
 
-void __update_cache(struct vm_area_struct *vma, unsigned long address,
-       pte_t pte)
+static void mips_flush_dcache_from_pte(pte_t pteval, unsigned long address)
 {
        struct page *page;
-       unsigned long pfn, addr;
-       int exec = (vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc;
+       unsigned long pfn = pte_pfn(pteval);
 
-       pfn = pte_pfn(pte);
        if (unlikely(!pfn_valid(pfn)))
                return;
+
        page = pfn_to_page(pfn);
        if (page_mapping(page) && Page_dcache_dirty(page)) {
-               addr = (unsigned long) page_address(page);
-               if (exec || pages_do_alias(addr, address & PAGE_MASK))
-                       flush_data_cache_page(addr);
+               unsigned long page_addr = (unsigned long) page_address(page);
+
+               if (!cpu_has_ic_fills_f_dc ||
+                   pages_do_alias(page_addr, address & PAGE_MASK))
+                       flush_data_cache_page(page_addr);
                ClearPageDcacheDirty(page);
        }
 }
 
+void set_pte_at(struct mm_struct *mm, unsigned long addr,
+        pte_t *ptep, pte_t pteval)
+{
+        if (cpu_has_dc_aliases || !cpu_has_ic_fills_f_dc) {
+                if (pte_present(pteval))
+                        mips_flush_dcache_from_pte(pteval, addr);
+        }
+
+        set_pte(ptep, pteval);
+}
+
 unsigned long _page_cachable_default;
 EXPORT_SYMBOL(_page_cachable_default);