X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Ffremap.c;h=b6ec85abbb39cc22dac7e9c309953c60a22e921c;hb=c654b8a9cba6002aad1c01919e4928a79a4a6dcf;hp=c395b1abf08275dc1d22a570f259f495cdb2cbc7;hpb=3ee6dafc677a68e461a7ddafc94a580ebab80735;p=safe%2Fjmp%2Flinux-2.6

diff --git a/mm/fremap.c b/mm/fremap.c
index c395b1a..b6ec85a 100644
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -5,7 +5,7 @@
  *
  * started by Ingo Molnar, Copyright (C) 2002, 2003
  */
-
+#include <linux/backing-dev.h>
 #include <linux/mm.h>
 #include <linux/swap.h>
 #include <linux/file.h>
@@ -15,11 +15,14 @@
 #include <linux/rmap.h>
 #include <linux/module.h>
 #include <linux/syscalls.h>
+#include <linux/mmu_notifier.h>
 
 #include <asm/mmu_context.h>
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 
+#include "internal.h"
+
 static void zap_pte(struct mm_struct *mm, struct vm_area_struct *vma,
 			unsigned long addr, pte_t *ptep)
 {
@@ -34,7 +37,7 @@ static void zap_pte(struct mm_struct *mm, struct vm_area_struct *vma,
 		if (page) {
 			if (pte_dirty(pte))
 				set_page_dirty(page);
-			page_remove_rmap(page, vma);
+			page_remove_rmap(page);
 			page_cache_release(page);
 			update_hiwater_rss(mm);
 			dec_mm_counter(mm, file_rss);
@@ -97,26 +100,28 @@ static int populate_range(struct mm_struct *mm, struct vm_area_struct *vma,
 
 }
 
-/***
- * sys_remap_file_pages - remap arbitrary pages of a shared backing store
- *                        file within an existing vma.
+/**
+ * sys_remap_file_pages - remap arbitrary pages of an existing VM_SHARED vma
  * @start: start of the remapped virtual memory range
  * @size: size of the remapped virtual memory range
- * @prot: new protection bits of the range
- * @pgoff: to be mapped page of the backing store file
+ * @prot: new protection bits of the range (see NOTE)
+ * @pgoff: to-be-mapped page of the backing store file
  * @flags: 0 or MAP_NONBLOCKED - the later will cause no IO.
  *
- * this syscall works purely via pagetables, so it's the most efficient
+ * sys_remap_file_pages remaps arbitrary pages of an existing VM_SHARED vma
+ * (shared backing store file).
+ *
+ * This syscall works purely via pagetables, so it's the most efficient
  * way to map the same (large) file into a given virtual window. Unlike
  * mmap()/mremap() it does not create any new vmas. The new mappings are
  * also safe across swapout.
  *
- * NOTE: the 'prot' parameter right now is ignored, and the vma's default
- * protection is used. Arbitrary protections might be implemented in the
- * future.
+ * NOTE: the @prot parameter right now is ignored (but must be zero),
+ * and the vma's default protection is used. Arbitrary protections
+ * might be implemented in the future.
  */
-asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
-	unsigned long __prot, unsigned long pgoff, unsigned long flags)
+SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
+		unsigned long, prot, unsigned long, pgoff, unsigned long, flags)
 {
 	struct mm_struct *mm = current->mm;
 	struct address_space *mapping;
@@ -125,7 +130,7 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
 	int err = -EINVAL;
 	int has_write_lock = 0;
 
-	if (__prot)
+	if (prot)
 		return err;
 	/*
 	 * Sanitize the syscall parameters:
@@ -160,7 +165,7 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
 	if (vma->vm_private_data && !(vma->vm_flags & VM_NONLINEAR))
 		goto out;
 
-	if (!vma->vm_flags & VM_CAN_NONLINEAR)
+	if (!(vma->vm_flags & VM_CAN_NONLINEAR))
 		goto out;
 
 	if (end <= start || start < vma->vm_start || end > vma->vm_end)
@@ -188,10 +193,13 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
 		 */
 		if (mapping_cap_account_dirty(mapping)) {
 			unsigned long addr;
+			struct file *file = vma->vm_file;
 
 			flags &= MAP_NONBLOCK;
-			addr = mmap_region(vma->vm_file, start, size,
-					flags, vma->vm_flags, pgoff, 1);
+			get_file(file);
+			addr = mmap_region(file, start, size,
+					flags, vma->vm_flags, pgoff);
+			fput(file);
 			if (IS_ERR_VALUE(addr)) {
 				err = addr;
 			} else {
@@ -209,13 +217,31 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
 		spin_unlock(&mapping->i_mmap_lock);
 	}
 
+	if (vma->vm_flags & VM_LOCKED) {
+		/*
+		 * drop PG_Mlocked flag for over-mapped range
+		 */
+		unsigned int saved_flags = vma->vm_flags;
+		munlock_vma_pages_range(vma, start, start + size);
+		vma->vm_flags = saved_flags;
+	}
+
+	mmu_notifier_invalidate_range_start(mm, start, start + size);
 	err = populate_range(mm, vma, start, size, pgoff);
+	mmu_notifier_invalidate_range_end(mm, start, start + size);
 	if (!err && !(flags & MAP_NONBLOCK)) {
-		if (unlikely(has_write_lock)) {
-			downgrade_write(&mm->mmap_sem);
-			has_write_lock = 0;
+		if (vma->vm_flags & VM_LOCKED) {
+			/*
+			 * might be mapping previously unmapped range of file
+			 */
+			mlock_vma_pages_range(vma, start, start + size);
+		} else {
+			if (unlikely(has_write_lock)) {
+				downgrade_write(&mm->mmap_sem);
+				has_write_lock = 0;
+			}
+			make_pages_present(start, start+size);
 		}
-		make_pages_present(start, start+size);
 	}
 
 	/*
@@ -232,4 +258,3 @@ out:
 
 	return err;
 }
-