From: suzuki <suzuki@in.ibm.com>
Date: Wed, 27 Jul 2005 18:43:59 +0000 (-0700)
Subject: [PATCH] madvise() does not always return -EBADF on non-file mapped area
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=165cd40235732644b1856a5ed5e158c9b93f6010;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git

[PATCH] madvise() does not always return -EBADF on non-file mapped area

The madvise() system call returns -EBADF for areas which does not map to
files, only for *behaviour* request MADV_WILLNEED.

According to man pages, madvise returns :

EBADF - the map exists, but the area maps something that isn't a file.

Fixes bug 2995.

Signed-off-by: Suzuki K P <suzuki@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/mm/madvise.c b/mm/madvise.c
index 73180a22877..c8c01a12fea 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -83,9 +83,6 @@ static long madvise_willneed(struct vm_area_struct * vma,
 {
 	struct file *file = vma->vm_file;
 
-	if (!file)
-		return -EBADF;
-
 	if (file->f_mapping->a_ops->get_xip_page) {
 		/* no bad return value, but ignore advice */
 		return 0;
@@ -140,11 +137,16 @@ static long madvise_dontneed(struct vm_area_struct * vma,
 	return 0;
 }
 
-static long madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
-			unsigned long start, unsigned long end, int behavior)
+static long
+madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
+		unsigned long start, unsigned long end, int behavior)
 {
+	struct file *filp = vma->vm_file;
 	long error = -EBADF;
 
+	if (!filp)
+		goto  out;
+
 	switch (behavior) {
 	case MADV_NORMAL:
 	case MADV_SEQUENTIAL:
@@ -165,6 +167,7 @@ static long madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev
 		break;
 	}
 		
+out:
 	return error;
 }