From: Al Viro <viro@ftp.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org
Subject: [PATCH][RFC] getting rid of stupid loop in BUG()
Date: Tue, 24 Jul 2007 16:39:16 +0100 [thread overview]
Message-ID: <20070724153916.GS21668@ftp.linux.org.uk> (raw)
AFAICS, the patch below should do it for i386; instead of
using a dummy loop to tell gcc that this sucker never returns,
we do
static void __always_inline __noreturn __BUG(const char *file, int line);
containing the actual asm we want to insert and define BUG() as
__BUG(__FILE__, __LINE__). It looks safe, but I don't claim enough
experience with gcc __asm__ potential nastiness, so...
Comments, objections?
diff --git a/include/asm-i386/bug.h b/include/asm-i386/bug.h
index b0fd78c..294bc55 100644
--- a/include/asm-i386/bug.h
+++ b/include/asm-i386/bug.h
@@ -7,31 +7,27 @@
* The offending file and line are encoded encoded in the __bug_table section.
*/
-#ifdef CONFIG_BUG
#define HAVE_ARCH_BUG
-#ifdef CONFIG_DEBUG_BUGVERBOSE
-#define BUG() \
- do { \
- asm volatile("1:\tud2\n" \
- ".pushsection __bug_table,\"a\"\n" \
- "2:\t.long 1b, %c0\n" \
- "\t.word %c1, 0\n" \
- "\t.org 2b+%c2\n" \
- ".popsection" \
- : : "i" (__FILE__), "i" (__LINE__), \
- "i" (sizeof(struct bug_entry))); \
- for(;;) ; \
- } while(0)
+#define BUG() __BUG(__FILE__, __LINE__)
+
+#include <asm-generic/bug.h>
+#ifdef CONFIG_BUG
+static void __always_inline __noreturn __BUG(const char *file, int line)
+{
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+ asm volatile("1:\tud2\n"
+ ".pushsection __bug_table,\"a\"\n"
+ "2:\t.long 1b, %c0\n"
+ "\t.word %c1, 0\n"
+ "\t.org 2b+%c2\n"
+ ".popsection"
+ : : "i" (file), "i" (line),
+ "i" (sizeof(struct bug_entry)));
#else
-#define BUG() \
- do { \
- asm volatile("ud2"); \
- for(;;) ; \
- } while(0)
+ asm volatile("ud2");
#endif
+}
#endif
-
-#include <asm-generic/bug.h>
#endif
next reply other threads:[~2007-07-24 15:39 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-24 15:39 Al Viro [this message]
2007-07-24 16:56 ` [PATCH][RFC] getting rid of stupid loop in BUG() Jeremy Fitzhardinge
2007-07-24 17:03 ` H. Peter Anvin
2007-07-24 17:14 ` Al Viro
2007-07-24 17:28 ` H. Peter Anvin
2007-07-24 18:58 ` Jeremy Fitzhardinge
2007-07-24 19:01 ` H. Peter Anvin
2007-07-24 19:13 ` Jeremy Fitzhardinge
2007-07-24 20:04 ` Al Viro
2007-07-24 21:14 ` Jeremy Fitzhardinge
2007-07-25 2:31 ` Trent Piepho
2007-07-25 2:50 ` Keith Owens
2007-07-25 5:09 ` H. Peter Anvin
2007-07-25 6:24 ` Jeremy Fitzhardinge
2007-07-25 6:29 ` David Miller
2007-07-25 6:50 ` Heiko Carstens
2007-07-25 16:56 ` Linus Torvalds
2007-07-25 17:00 ` Jeremy Fitzhardinge
2007-07-25 17:03 ` H. Peter Anvin
2007-07-25 17:19 ` Linus Torvalds
2007-07-25 17:25 ` Al Viro
2007-07-25 17:36 ` Jeremy Fitzhardinge
2007-07-25 19:35 ` David Miller
2007-07-25 20:26 ` H. Peter Anvin
2007-07-25 19:28 ` David Miller
2007-07-25 17:19 ` Al Viro
2007-07-25 17:22 ` H. Peter Anvin
2007-07-25 17:26 ` Al Viro
2007-07-25 17:35 ` David Howells
2007-07-25 17:41 ` Jeremy Fitzhardinge
2007-07-25 20:29 ` Chuck Ebbert
2007-07-25 20:37 ` H. Peter Anvin
2007-07-25 22:01 ` David Miller
2007-07-25 18:24 ` Linus Torvalds
2007-07-25 17:36 ` Al Viro
2007-07-25 17:44 ` Jeremy Fitzhardinge
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=20070724153916.GS21668@ftp.linux.org.uk \
--to=viro@ftp.linux.org.uk \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@linux-foundation.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