X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=kernel%2Fsys.c;h=b5a8e844a96887e2d4253536a5a45dd2a0ca296e;hb=9bde4e671f2b1efa84c92608a5749dc97012c691;hp=11333311cf1c5da8aab5c1eaceaaaee671468676;hpb=02bbd06e489a9f56910973535152d3ec47f3fdcc;p=firefly-linux-kernel-4.4.55.git

diff --git a/kernel/sys.c b/kernel/sys.c
index 11333311cf1c..b5a8e844a968 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1855,11 +1855,13 @@ static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data
 		user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
 	}
 
-	if (prctl_map.exe_fd != (u32)-1)
+	if (prctl_map.exe_fd != (u32)-1) {
 		error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
-	down_read(&mm->mmap_sem);
-	if (error)
-		goto out;
+		if (error)
+			return error;
+	}
+
+	down_write(&mm->mmap_sem);
 
 	/*
 	 * We don't validate if these members are pointing to
@@ -1896,10 +1898,8 @@ static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data
 	if (prctl_map.auxv_size)
 		memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
 
-	error = 0;
-out:
-	up_read(&mm->mmap_sem);
-	return error;
+	up_write(&mm->mmap_sem);
+	return 0;
 }
 #endif /* CONFIG_CHECKPOINT_RESTORE */
 
@@ -1965,7 +1965,7 @@ static int prctl_set_mm(int opt, unsigned long addr,
 
 	error = -EINVAL;
 
-	down_read(&mm->mmap_sem);
+	down_write(&mm->mmap_sem);
 	vma = find_vma(mm, addr);
 
 	prctl_map.start_code	= mm->start_code;
@@ -2058,7 +2058,7 @@ static int prctl_set_mm(int opt, unsigned long addr,
 
 	error = 0;
 out:
-	up_read(&mm->mmap_sem);
+	up_write(&mm->mmap_sem);
 	return error;
 }