[PATCH] trace: Fix some checker warnings

From: David Howells
Date: Thu Dec 01 2022 - 15:08:46 EST


Fix some checker warning in the trace code:

(1) The declaration of tracing_max_lat_fops should be conditionally
defined like its definition.

(2) A number of trace functions, and their declarations where present,
should have __printf attributes.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---

include/linux/trace_events.h | 3 ++-
include/linux/trace_seq.h | 3 ++-
kernel/trace/trace.c | 2 ++
kernel/trace/trace.h | 2 +-
kernel/trace/trace_output.c | 5 +++--
5 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 20749bd9db71..112b08ca2c5c 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -235,7 +235,8 @@ void tracing_record_taskinfo_sched_switch(struct task_struct *prev,
void tracing_record_cmdline(struct task_struct *task);
void tracing_record_tgid(struct task_struct *task);

-int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...);
+int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
+ __printf(3, 4);

struct event_filter;

diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h
index 5a2c650d9e1c..0c4c7587d6c3 100644
--- a/include/linux/trace_seq.h
+++ b/include/linux/trace_seq.h
@@ -97,7 +97,8 @@ extern int trace_seq_hex_dump(struct trace_seq *s, const char *prefix_str,
const void *buf, size_t len, bool ascii);

#else /* CONFIG_TRACING */
-static inline void trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
+static inline __printf(2, 3)
+void trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
{
}
static inline void
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5cfc95a52bc3..9da61a54e187 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1692,7 +1692,9 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
}

unsigned long __read_mostly tracing_thresh;
+#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
static const struct file_operations tracing_max_lat_fops;
+#endif

#ifdef LATENCY_FS_NOTIFY

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index d42e24507152..ecc6120116da 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -615,7 +615,7 @@ void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
bool trace_is_tracepoint_string(const char *str);
const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
- va_list ap);
+ va_list ap) __printf(2, 0);

int trace_empty(struct trace_iterator *iter);

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 67f47ea27921..7039cd883c8b 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -323,8 +323,9 @@ void trace_event_printf(struct trace_iterator *iter, const char *fmt, ...)
}
EXPORT_SYMBOL(trace_event_printf);

-static int trace_output_raw(struct trace_iterator *iter, char *name,
- char *fmt, va_list ap)
+static __printf(3, 0)
+int trace_output_raw(struct trace_iterator *iter, char *name,
+ char *fmt, va_list ap)
{
struct trace_seq *s = &iter->seq;