From: Wu Fengguang <fengguang.wu@intel.com>
To: Andreas Dilger <adilger@sun.com>
Cc: "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"davem@davemloft.net" <davem@davemloft.net>,
"eparis@redhat.com" <eparis@redhat.com>,
"hch@infradead.org" <hch@infradead.org>,
"jamie@shareable.org" <jamie@shareable.org>,
"rdreier@cisco.com" <rdreier@cisco.com>,
"schwab@linux-m68k.org" <schwab@linux-m68k.org>,
"sfr@canb.auug.org.au" <sfr@canb.auug.org.au>
Subject: [PATCH] vfs: O_* bit numbers uniqueness check fix 2
Date: Fri, 12 Mar 2010 21:42:03 +0800 [thread overview]
Message-ID: <20100312134203.GB6502@localhost> (raw)
In-Reply-To: <6DD92A2F-63EB-44A5-A0B7-DCAD21A9BD2B@sun.com>
Follow the comment by Andreas:
It's non-obvious why there are 18 flags listed here, but the hweight
is only 17? Presumably this is because O_RDONLY has value 0, but that
should at least be
listed in a comment, or the test could be written more explicitly, like:
BUILD_BUG_ON(18 - 1 /* for O_RDONLY being 0 */ != HWEIGHT32(
CC: Andreas Dilger <adilger@sun.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
---
fs/fcntl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- linux-mm.orig/fs/fcntl.c 2010-03-12 21:39:01.000000000 +0800
+++ linux-mm/fs/fcntl.c 2010-03-12 21:38:42.000000000 +0800
@@ -742,7 +742,7 @@ EXPORT_SYMBOL(kill_fasync);
static int __init fcntl_init(void)
{
/* please add new bits here to ensure allocation uniqueness */
- BUILD_BUG_ON(17 != HWEIGHT32(
+ BUILD_BUG_ON(18 - 1 /* for O_RDONLY being 0 */ != HWEIGHT32(
O_RDONLY | O_WRONLY | O_RDWR |
O_CREAT | O_EXCL | O_NOCTTY |
O_TRUNC | O_APPEND | O_NONBLOCK |
prev parent reply other threads:[~2010-03-12 14:35 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-11 22:11 [patch 4/6] vfs: O_* bit numbers uniqueness check akpm
2010-03-11 23:11 ` Eric Paris
2010-03-12 13:41 ` [PATCH] vfs: O_* bit numbers uniqueness check fix Wu Fengguang
2010-03-12 15:01 ` Eric Paris
2010-03-12 15:14 ` Wu Fengguang
2010-03-12 15:15 ` Wu Fengguang
2010-03-12 0:39 ` [patch 4/6] vfs: O_* bit numbers uniqueness check Andreas Dilger
2010-03-12 13:42 ` Wu Fengguang [this message]
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