From: Hawrylewicz Czarnowski, Przemyslaw <przemyslaw.hawrylewicz.czarnowski@intel.com>
Date: Wed, 7 Dec 2011 01:15:55 +0000 (+1100)
Subject: fix: imsm: validate strip size - tuned up
X-Git-Tag: mdadm-3.2.3~38
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=70eb8219ac128ca88c1beff1e9cf48ed23846eea;p=thirdparty%2Fmdadm.git

fix: imsm: validate strip size - tuned up

Neil's proposal seems more reasonable and shows what is really going on
here.

Signed-off-by: Przemyslaw Czarnowski <przemyslaw.hawrylewicz.czarnowski@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/platform-intel.h b/platform-intel.h
index 99450ba7..c997f1b8 100644
--- a/platform-intel.h
+++ b/platform-intel.h
@@ -124,13 +124,12 @@ static inline int imsm_orom_has_raid5(const struct imsm_orom *orom)
 static inline int imsm_orom_has_chunk(const struct imsm_orom *orom, int chunk)
 {
 	int fs = ffs(chunk);
-	int orom_chunk_bit;
-
 	if (!fs)
 		return 0;
 	fs--; /* bit num to bit index */
-	orom_chunk_bit = (orom->sss & (1 << (fs - 1)));
-	return orom_chunk_bit && 1 << orom_chunk_bit == chunk;
+	if (chunk & (chunk-1))
+		return 0; /* not a power of 2 */
+	return !!(orom->sss & (1 << (fs - 1)));
 }