From: Dave Hansen <dave@linux.vnet.ibm.com>
To: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Dave Hansen <dave@linux.vnet.ibm.com>
Subject: [PATCH] make sparse happy with gfp.h
Date: Thu, 14 Apr 2011 16:42:17 -0700 [thread overview]
Message-ID: <20110414234216.9E31DBD9@kernel> (raw)
Running sparse on page_alloc.c today, it errors out:
include/linux/gfp.h:254:17: error: bad constant expression
include/linux/gfp.h:254:17: error: cannot size expression
which is a line in gfp_zone():
BUILD_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
That's really unfortunate, because it ends up hiding all of the other
legitimate sparse messages like this:
mm/page_alloc.c:5315:59: warning: incorrect type in argument 1 (different base types)
mm/page_alloc.c:5315:59: expected unsigned long [unsigned] [usertype] size
mm/page_alloc.c:5315:59: got restricted gfp_t [usertype] <noident>
...
Having sparse be able to catch these very oopsable bugs is a lot more
important than keeping a BUILD_BUG_ON(). Kill the BUILD_BUG_ON().
Compiles on x86_64 with and without CONFIG_DEBUG_VM=y. defconfig
boots fine for me.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
---
linux-2.6.git-dave/include/linux/gfp.h | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff -puN include/linux/gfp.h~make-sparse-happy-with-gfp_h include/linux/gfp.h
--- linux-2.6.git/include/linux/gfp.h~make-sparse-happy-with-gfp_h 2011-04-14 14:47:02.629275904 -0700
+++ linux-2.6.git-dave/include/linux/gfp.h 2011-04-14 14:47:38.813272674 -0700
@@ -249,14 +249,9 @@ static inline enum zone_type gfp_zone(gf
z = (GFP_ZONE_TABLE >> (bit * ZONES_SHIFT)) &
((1 << ZONES_SHIFT) - 1);
-
- if (__builtin_constant_p(bit))
- BUILD_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
- else {
#ifdef CONFIG_DEBUG_VM
- BUG_ON((GFP_ZONE_BAD >> bit) & 1);
+ BUG_ON((GFP_ZONE_BAD >> bit) & 1);
#endif
- }
return z;
}
_
next reply other threads:[~2011-04-14 23:42 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-14 23:42 Dave Hansen [this message]
2011-04-15 3:14 ` [PATCH] make sparse happy with gfp.h KOSAKI Motohiro
2011-04-15 5:07 ` Dave Hansen
2011-04-15 5:33 ` KOSAKI Motohiro
2011-04-15 14:27 ` [PATCH] fix sparse happy borkage when including gfp.h Dave Hansen
2011-04-15 5:09 ` [PATCH] define dummy BUILD_BUG_ON definition for sparse KOSAKI Motohiro
2011-04-15 5:11 ` [PATCH] define __must_be_array() for __CHECKER__ KOSAKI Motohiro
2011-04-15 5:11 ` [PATCH] Undef __compiletime_{warning,error} if __CHECKER__ is defined KOSAKI Motohiro
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110414234216.9E31DBD9@kernel \
--to=dave@linux.vnet.ibm.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).