linux-kernel - Re: [PATCH 2/4] ARM: add IPI tracepoints

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

Message-ID: <20140718172221.6dbe83e4@gandalf.local.home>
Date:	Fri, 18 Jul 2014 17:22:21 -0400
From:	Steven Rostedt <rostedt@...dmis.org>
To:	Nicolas Pitre <nicolas.pitre@...aro.org>
Cc:	Ingo Molnar <mingo@...hat.com>,
	Daniel Lezcano <daniel.lezcano@...aro.org>,
	Russell King - ARM Linux <linux@....linux.org.uk>,
	Catalin Marinas <catalin.marinas@....com>,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linaro-kernel@...ts.linaro.org
Subject: Re: [PATCH 2/4] ARM: add IPI tracepoints

On Fri, 18 Jul 2014 16:55:42 -0400 (EDT)
Nicolas Pitre <nicolas.pitre@...aro.org> wrote:

> 
> Here's the patch I have at the head of the series now, with the above
> ugliness changed to an unconditional __tracepoint_string attribute.
> 

I was thinking of something like this. Feel free to add this to your
series.

-- Steve

From: Steven Rostedt <rostedt@...dmis.org>
Subject: [PATCH] tracing: Do not do anything special with tracepoint_string when tracing is disabled

When CONFIG_TRACING is not enabled, there's no reason to save the trace
strings either by the linker or as a static variable that can be
referenced later. Simply pass back the string that is given to
tracepoint_string().

Signed-off-by: Steven Rostedt <rostedt@...dmis.org>
---
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index cff3106..b296363 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -574,6 +574,7 @@ do {									\
 		__trace_printk(ip, fmt, ##args);			\
 } while (0)
 
+#ifdef CONFIG_TRACING
 /**
  * tracepoint_string - register constant persistent string to trace system
  * @str - a constant persistent string that will be referenced in tracepoints
@@ -607,6 +608,15 @@ do {									\
 		___tp_str;						\
 	})
 #define __tracepoint_string	__attribute__((section("__tracepoint_str")))
+#else
+/*
+ * tracepoint_string() is used to save the string address for userspace
+ * tracing tools. When tracing isn't configured, there's no need to save
+ * anything.
+ */
+# define tracepoint_string(str) str
+# define __tracepoint_string
+#endif
 
 #ifdef CONFIG_PERF_EVENTS
 struct perf_event;

--
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/