[PATCH] libfs: fix simple_attr_write on 32bit machine

[Akinobu Mita]

Assume that /sys/kernel/debug/dummy64 is debugfs file created by
debugfs_create_x64().

	# cd /sys/kernel/debug
	# echo 0x1234567812345678 > dummy64
	# cat dummy64
	0x0000000012345678

	# echo 0x80000000 > dummy64
	# cat dummy64
	0xffffffff80000000

The value more than INT_MAX cannot be written to the debugfs file
created by debugfs_create_u64 or debugfs_create_x64 on 32bit machine.
Because simple_attr_write() uses simple_strtol() for the conversion.

To fix this, use simple_strtoll() instead.

Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
 fs/libfs.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/libfs.c b/fs/libfs.c
index c88eab5..275ca474 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -822,7 +822,7 @@ ssize_t simple_attr_write(struct file *file, const char __user *buf,
 		goto out;
 
 	attr->set_buf[size] = '\0';
-	val = simple_strtol(attr->set_buf, NULL, 0);
+	val = simple_strtoll(attr->set_buf, NULL, 0);
 	ret = attr->set(attr->data, val);
 	if (ret == 0)
 		ret = len; /* on success, claim we got the whole input */
-- 
1.7.4.4

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