From: Andrew Morton <akpm@linux-foundation.org>
Date: Tue, 26 Oct 2010 21:21:19 +0000 (-0700)
Subject: kfifo: disable __kfifo_must_check_helper()
X-Git-Tag: firefly_0821_release~9833^2~79^2^2~191
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=23d1f7ce08dfc77a0e8cdf0ade18df0c1505d0de;p=firefly-linux-kernel-4.4.55.git

kfifo: disable __kfifo_must_check_helper()

commit 52c5171214ff3327961d0ce0db7e8d2ce55004fd upstream.

This helper is wrong: it coerces signed values into unsigned ones, so code
such as

	if (kfifo_alloc(...) < 0) {
		error
	}

will fail to detect the error.

So let's disable __kfifo_must_check_helper() for 2.6.36.

Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/include/linux/kfifo.h b/include/linux/kfifo.h
index 62dbee554f60..c238ad2f82ea 100644
--- a/include/linux/kfifo.h
+++ b/include/linux/kfifo.h
@@ -171,11 +171,8 @@ struct kfifo_rec_ptr_2 __STRUCT_KFIFO_PTR(unsigned char, 2, void);
 	}
 
 
-static inline unsigned int __must_check
-__kfifo_must_check_helper(unsigned int val)
-{
-	return val;
-}
+/* __kfifo_must_check_helper() is temporarily disabled because it was faulty */
+#define __kfifo_must_check_helper(x) (x)
 
 /**
  * kfifo_initialized - Check if the fifo is initialized