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Message-Id: <20170517080554.1915-1-felipe.balbi@linux.intel.com>
Date: Wed, 17 May 2017 11:05:54 +0300
From: Felipe Balbi <felipe.balbi@...ux.intel.com>
To: Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Steven Rostedt <rostedt@...dmis.org>,
Ingo Molnar <mingo@...hat.com>
Cc: linux-kernel@...r.kernel.org,
Chunyan Zhang <zhang.chunyan@...aro.org>,
Felipe Balbi <felipe.balbi@...ux.intel.com>
Subject: [PATCH] kernel: trace: pass export pointer as argument to ->write()
That way, users don't need to keep a global static pointer and can
rely on container_of() to fetch their own structure.
Signed-off-by: Felipe Balbi <felipe.balbi@...ux.intel.com>
---
I'm working on exposing this data over a USB peripheral controller and
I really can't have a global pointer there.
drivers/hwtracing/stm/ftrace.c | 6 ++++--
include/linux/trace.h | 2 +-
kernel/trace/trace.c | 2 +-
3 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/hwtracing/stm/ftrace.c b/drivers/hwtracing/stm/ftrace.c
index bd126a7c6da2..371b8333d9ae 100644
--- a/drivers/hwtracing/stm/ftrace.c
+++ b/drivers/hwtracing/stm/ftrace.c
@@ -42,9 +42,11 @@ static struct stm_ftrace {
* @len: length of the data packet
*/
static void notrace
-stm_ftrace_write(const void *buf, unsigned int len)
+stm_ftrace_write(struct trace_export *export, const void *buf, unsigned int len)
{
- stm_source_write(&stm_ftrace.data, STM_FTRACE_CHAN, buf, len);
+ struct stm_ftrace *stm = container_of(export, struct stm_ftrace, ftrace);
+
+ stm_source_write(stm->data, STM_FTRACE_CHAN, buf, len);
}
static int stm_ftrace_link(struct stm_source_data *data)
diff --git a/include/linux/trace.h b/include/linux/trace.h
index 9330a58e2651..477aed6f0caa 100644
--- a/include/linux/trace.h
+++ b/include/linux/trace.h
@@ -17,7 +17,7 @@
*/
struct trace_export {
struct trace_export __rcu *next;
- void (*write)(const void *, unsigned int);
+ void (*write)(struct trace_export *, const void *, unsigned int);
};
int register_ftrace_export(struct trace_export *export);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c4536c449021..6a96652a3b0f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2317,7 +2317,7 @@ trace_process_export(struct trace_export *export,
entry = ring_buffer_event_data(event);
size = ring_buffer_event_length(event);
- export->write(entry, size);
+ export->write(export, entry, size);
}
static DEFINE_MUTEX(ftrace_export_lock);
--
2.11.0.295.gd7dffce1ce
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