X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=mm%2Fmadvise.c;h=944b5e52d812f051fb2bffaed33a4288ba4c920e;hb=6a77f38946aaee1cd85eeec6cf4229b204c15071;hp=81c4ea30c75e60b9001127697045d000ae075fd1;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git

diff --git a/mm/madvise.c b/mm/madvise.c
index 81c4ea30c..944b5e52d 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -7,7 +7,8 @@
 
 #include <linux/mman.h>
 #include <linux/pagemap.h>
-
+#include <linux/syscalls.h>
+#include <linux/hugetlb.h>
 
 /*
  * We can potentially split a vm area into separate
@@ -17,21 +18,23 @@ static long madvise_behavior(struct vm_area_struct * vma, unsigned long start,
 			     unsigned long end, int behavior)
 {
 	struct mm_struct * mm = vma->vm_mm;
-	int error;
+	int error = 0;
 
 	if (start != vma->vm_start) {
 		error = split_vma(mm, vma, start, 1);
 		if (error)
-			return -EAGAIN;
+			goto out;
 	}
 
 	if (end != vma->vm_end) {
 		error = split_vma(mm, vma, end, 0);
 		if (error)
-			return -EAGAIN;
+			goto out;
 	}
 
-	spin_lock(&mm->page_table_lock);
+	/*
+	 * vm_flags is protected by the mmap_sem held in write mode.
+	 */
 	VM_ClearReadHint(vma);
 
 	switch (behavior) {
@@ -44,9 +47,11 @@ static long madvise_behavior(struct vm_area_struct * vma, unsigned long start,
 	default:
 		break;
 	}
-	spin_unlock(&mm->page_table_lock);
 
-	return 0;
+out:
+	if (error == -ENOMEM)
+		error = -EAGAIN;
+	return error;
 }
 
 /*
@@ -92,16 +97,14 @@ static long madvise_willneed(struct vm_area_struct * vma,
 static long madvise_dontneed(struct vm_area_struct * vma,
 			     unsigned long start, unsigned long end)
 {
-	struct zap_details details;
-
-	if (vma->vm_flags & VM_LOCKED)
+	if ((vma->vm_flags & VM_LOCKED) || is_vm_hugetlb_page(vma))
 		return -EINVAL;
 
 	if (unlikely(vma->vm_flags & VM_NONLINEAR)) {
-		details.check_mapping = NULL;
-		details.nonlinear_vma = vma;
-		details.first_index = 0;
-		details.last_index = ULONG_MAX;
+		struct zap_details details = {
+			.nonlinear_vma = vma,
+			.last_index = ULONG_MAX,
+		};
 		zap_page_range(vma, start, end - start, &details);
 	} else
 		zap_page_range(vma, start, end - start, NULL);
@@ -170,18 +173,24 @@ static long madvise_vma(struct vm_area_struct * vma, unsigned long start,
  *  -EBADF  - map exists, but area maps something that isn't a file.
  *  -EAGAIN - a kernel resource was temporarily unavailable.
  */
-asmlinkage long sys_madvise(unsigned long start, size_t len, int behavior)
+asmlinkage long sys_madvise(unsigned long start, size_t len_in, int behavior)
 {
 	unsigned long end;
 	struct vm_area_struct * vma;
 	int unmapped_error = 0;
 	int error = -EINVAL;
+	size_t len;
 
 	down_write(&current->mm->mmap_sem);
 
 	if (start & ~PAGE_MASK)
 		goto out;
-	len = (len + ~PAGE_MASK) & PAGE_MASK;
+	len = (len_in + ~PAGE_MASK) & PAGE_MASK;
+
+	/* Check to see whether len was rounded up from small -ve to zero */
+	if (len_in && !len)
+		goto out;
+
 	end = start + len;
 	if (end < start)
 		goto out;