linux-kernel - [PATCH] Resurrect old pr_debug() semantics as pr

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Mon,  6 Apr 2009 14:30:03 +1000 (EST)
From:	Michael Ellerman <michael@...erman.id.au>
To:	<linux-kernel@...r.kernel.org>
Cc:	Andrew Morton <akpm@...l.org>, <gnb@....com>, <jbaron@...hat.com>
Subject: [PATCH] Resurrect old pr_debug() semantics as pr_devel()

pr_debug() used to produce zero code unless DEBUG was #defined. This is
now no longer the case in practice[1].

There are places where it's useful to have debugging printks, but we
don't want them to generate any code in production kernels.

So add a new macro, pr_devel(), for _devel_opment, to provide the old
semantics, ie. if the programmer doesn't explicitly enable debugging,
no code is produced.

[1]: You can turn CONFIG_DYNAMIC_DEBUG off, but it's enabled in at least
     one distro kernel, so it's not really a solution.

Signed-off-by: Michael Ellerman <michael@...erman.id.au>
---
 include/linux/kernel.h |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index d9e75ec..883cd44 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -377,6 +377,15 @@ static inline char *pack_hex_byte(char *buf, u8 byte)
 #define pr_cont(fmt, ...) \
 	printk(KERN_CONT fmt, ##__VA_ARGS__)
 
+/* pr_devel() should produce zero code unless DEBUG is defined */
+#ifdef DEBUG
+#define pr_devel(fmt, ...) \
+	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
+#else
+#define pr_devel(fmt, ...) \
+	({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
+#endif
+
 /* If you are writing a driver, please use dev_dbg instead */
 #if defined(DEBUG)
 #define pr_debug(fmt, ...) \
-- 
1.6.1.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/