threads and fork on machine with VIPT-WB cache

Commit Message

John David Anglin April 5, 2010, 2:51 a.m. UTC

None

Patch

diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
index a27d2e2..b140d5c 100644
--- a/arch/parisc/include/asm/pgtable.h
+++ b/arch/parisc/include/asm/pgtable.h
@@ -14,6 +14,7 @@ 
 #include <linux/bitops.h>
 #include <asm/processor.h>
 #include <asm/cache.h>
+extern void flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn);
 
 /*
  * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
@@ -456,17 +457,22 @@  static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 	return old_pte;
 }
 
-static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+static inline void ptep_set_wrprotect(struct vm_area_struct *vma, struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 #ifdef CONFIG_SMP
 	unsigned long new, old;
+#endif
+	pte_t old_pte = *ptep;
+
+	if (atomic_read(&mm->mm_users) > 1)
+		flush_cache_page(vma, addr, pte_pfn(old_pte));
 
+#ifdef CONFIG_SMP
 	do {
 		old = pte_val(*ptep);
 		new = pte_val(pte_wrprotect(__pte (old)));
 	} while (cmpxchg((unsigned long *) ptep, old, new) != old);
 #else
-	pte_t old_pte = *ptep;
 	set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
 #endif
 }
diff --git a/mm/memory.c b/mm/memory.c
index 09e4b1b..21c2916 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -616,7 +616,7 @@  copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	 * in the parent and the child
 	 */
 	if (is_cow_mapping(vm_flags)) {
-		ptep_set_wrprotect(src_mm, addr, src_pte);
+		ptep_set_wrprotect(vma, src_mm, addr, src_pte);
 		pte = pte_wrprotect(pte);
 	}