linux-kernel - [PATCH 2/4] initramfs: mark dirp as a __user pointer on clean

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Date:	Thu, 19 Aug 2010 12:37:42 +0900
From:	Namhyung Kim <namhyung@...il.com>
To:	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	linux-kernel@...r.kernel.org
Subject: [PATCH 2/4] initramfs: mark dirp as a __user pointer on clean_rootfs()

dirp is used for calling syscall routines so it would be better to be a user
pointer unless we want to cast it on every syscalls.

Signed-off-by: Namhyung Kim <namhyung@...il.com>
---
 init/initramfs.c |   15 +++++++++------
 1 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/init/initramfs.c b/init/initramfs.c
index 75a43c5..d90d1cf 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -526,7 +526,7 @@ static void __init clean_rootfs(void)
 {
 	int fd;
 	void *buf;
-	struct linux_dirent64 *dirp;
+	struct linux_dirent64 __user *dirp;
 	int num;
 
 	fd = sys_open((const char __user __force *) "/", O_RDONLY, 0);
@@ -540,14 +540,16 @@ static void __init clean_rootfs(void)
 		return;
 	}
 
-	dirp = buf;
+	dirp = (struct linux_dirent64 __user __force *) buf;
 	num = sys_getdents64(fd, dirp, BUF_SIZE);
 	while (num > 0) {
 		while (num > 0) {
 			struct stat st;
 			int ret;
+			unsigned short len;
 
-			ret = sys_newlstat(dirp->d_name, &st);
+			ret = sys_newlstat(dirp->d_name,
+					   (struct stat __user __force *)&st);
 			WARN_ON_ONCE(ret);
 			if (!ret) {
 				if (S_ISDIR(st.st_mode))
@@ -556,10 +558,11 @@ static void __init clean_rootfs(void)
 					sys_unlink(dirp->d_name);
 			}
 
-			num -= dirp->d_reclen;
-			dirp = (void *)dirp + dirp->d_reclen;
+			len = ((struct linux_dirent64 __force *) dirp)->d_reclen;
+			num -= len;
+			dirp = (void __user *)dirp + len;
 		}
-		dirp = buf;
+		dirp = (struct linux_dirent64 __user __force *) buf;
 		memset(buf, 0, BUF_SIZE);
 		num = sys_getdents64(fd, dirp, BUF_SIZE);
 	}
-- 
1.7.0.4

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