linux-kernel - [PATCH v3 1/2] dynamic debug: split enable and printk flags

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20200825153338.17061-2-vincent.whitchurch@axis.com>
Date:   Tue, 25 Aug 2020 17:33:37 +0200
From:   Vincent Whitchurch <vincent.whitchurch@...s.com>
To:     <jbaron@...mai.com>, <rostedt@...dmis.org>, <mingo@...hat.com>
CC:     <kernel@...s.com>, <corbet@....net>, <pmladek@...e.com>,
        <sergey.senozhatsky@...il.com>, <john.ogness@...utronix.de>,
        <linux-kernel@...r.kernel.org>,
        Vincent Whitchurch <vincent.whitchurch@...s.com>
Subject: [PATCH v3 1/2] dynamic debug: split enable and printk flags

We're going to add support to allow dynamic debug locations to print to
a trace event, and that will make _DPRINTK_FLAGS_PRINT a bit ambiguous.
Will it mean printk(), or printing to the trace event, or any of the
two?

To make it clearer, split _DPRINTK_FLAGS_PRINT into two:

 (1) _DPRINTK_FLAGS_PRINTK for turning on the printk() and
 (2) _DPRINTK_FLAGS_ENABLE when checking if the dynamic debug location
     is enabled.

_DPRINTK_FLAGS_ENABLE is currently just an alias of
_DPRINTK_FLAGS_PRINTK but will later also include a new flag for
enabling printing to the trace event.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@...s.com>
---
 include/linux/dynamic_debug.h | 9 +++++----
 lib/dynamic_debug.c           | 8 ++++----
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index aa9ff9e1c0b3..738421898aac 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -27,13 +27,14 @@ struct _ddebug {
 	 * writes commands to <debugfs>/dynamic_debug/control
 	 */
 #define _DPRINTK_FLAGS_NONE	0
-#define _DPRINTK_FLAGS_PRINT	(1<<0) /* printk() a message using the format */
+#define _DPRINTK_FLAGS_PRINTK	(1<<0) /* printk() a message using the format */
 #define _DPRINTK_FLAGS_INCL_MODNAME	(1<<1)
 #define _DPRINTK_FLAGS_INCL_FUNCNAME	(1<<2)
 #define _DPRINTK_FLAGS_INCL_LINENO	(1<<3)
 #define _DPRINTK_FLAGS_INCL_TID		(1<<4)
+#define _DPRINTK_FLAGS_ENABLE		_DPRINTK_FLAGS_PRINTK
 #if defined DEBUG
-#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
+#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINTK
 #else
 #define _DPRINTK_FLAGS_DEFAULT 0
 #endif
@@ -111,10 +112,10 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
 
 #ifdef DEBUG
 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
-	likely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
+	likely(descriptor.flags & _DPRINTK_FLAGS_ENABLE)
 #else
 #define DYNAMIC_DEBUG_BRANCH(descriptor) \
-	unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
+	unlikely(descriptor.flags & _DPRINTK_FLAGS_ENABLE)
 #endif
 
 #endif
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 1d012e597cc3..88af85cb5222 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -84,7 +84,7 @@ static inline const char *trim_prefix(const char *path)
 }
 
 static struct { unsigned flag:8; char opt_char; } opt_array[] = {
-	{ _DPRINTK_FLAGS_PRINT, 'p' },
+	{ _DPRINTK_FLAGS_PRINTK, 'p' },
 	{ _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
 	{ _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
 	{ _DPRINTK_FLAGS_INCL_LINENO, 'l' },
@@ -206,10 +206,10 @@ static int ddebug_change(const struct ddebug_query *query,
 			if (newflags == dp->flags)
 				continue;
 #ifdef CONFIG_JUMP_LABEL
-			if (dp->flags & _DPRINTK_FLAGS_PRINT) {
-				if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT))
+			if (dp->flags & _DPRINTK_FLAGS_ENABLE) {
+				if (!(modifiers->flags & _DPRINTK_FLAGS_ENABLE))
 					static_branch_disable(&dp->key.dd_key_true);
-			} else if (modifiers->flags & _DPRINTK_FLAGS_PRINT)
+			} else if (modifiers->flags & _DPRINTK_FLAGS_ENABLE)
 				static_branch_enable(&dp->key.dd_key_true);
 #endif
 			dp->flags = newflags;
-- 
2.28.0