[PATCH] 2.5.27 read_write

From: Marcin Dalecki <dalecki@evision.ag>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [PATCH] 2.5.27 read_write
Date: Mon, 22 Jul 2002 16:08:30 +0200	[thread overview]
Message-ID: <3D3C11DE.7010000@evision.ag> (raw)
In-Reply-To: Pine.LNX.4.44.0207201218390.1230-100000@home.transmeta.com

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- This is making the read_write.c C.

- It is fixing completely confused wild casting to 32 bits.

- Actually adding a comment explaining the obscure code, which is
   relying on integer arithmetics overflow.

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diff -urN linux-2.5.27/fs/read_write.c linux/fs/read_write.c

--- linux-2.5.27/fs/read_write.c	2002-07-22 13:08:04.000000000 +0200
+++ linux/fs/read_write.c	2002-07-22 13:44:04.000000000 +0200
@@ -307,11 +307,11 @@
 	ret = -EINVAL;
 	for (i = 0 ; i < count ; i++) {
 		size_t tmp = tot_len;
-		int len = iov[i].iov_len;
-		if (len < 0)
-			goto out;
-		(u32)tot_len += len;
-		if (tot_len < tmp || tot_len < (u32)len)
+		size_t len = iov[i].iov_len;
+
+		tot_len += len;
+		/* check for overflows */
+		if (tot_len < tmp || tot_len < len)
 			goto out;
 	}
 
