From: Felipe Balbi By passing an export descriptor to the write function, users don't need to keep a global static pointer and can rely on container_of() to fetch their own structure. Link: http://lkml.kernel.org/r/20170602102025.5140-1-felipe.balbi@linux.intel.com Acked-by: Steven Rostedt (VMware) Reviewed-by: Chunyan Zhang Signed-off-by: Felipe Balbi Signed-off-by: Steven Rostedt (VMware) --- 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..7da75644c750 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 d24991c1fef3..b95ffb2188ab 100644 --- a/include/linux/trace.h +++ b/include/linux/trace.h @@ -18,7 +18,7 @@ */ 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 9f3f043ba3b7..59518b8126d0 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2415,7 +2415,7 @@ 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); -- 2.13.2