[PATCH 5.4 41/54] tracing: Fix userstacktrace option for instances

Greg Kroah-Hartman
2020-12-10T15:30:26Z

From: Steven Rostedt (VMware) <rostedt@goodmis.org>

commit bcee5278958802b40ee8b26679155a6d9231783e upstream.

When the instances were able to use their own options, the userstacktrace
option was left hardcoded for the top level. This made the instance
userstacktrace option bascially into a nop, and will confuse users that set
it, but nothing happens (I was confused when it happened to me!)

Cc: stable@vger.kernel.org
Fixes: 16270145ce6b ("tracing: Add trace options for core options to instances")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
kernel/trace/trace.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -160,7 +160,8 @@ static union trace_eval_map_item *trace_
#endif /* CONFIG_TRACE_EVAL_MAP_FILE */

static int tracing_set_tracer(struct trace_array *tr, const char *buf);
-static void ftrace_trace_userstack(struct ring_buffer *buffer,
+static void ftrace_trace_userstack(struct trace_array *tr,
+ struct ring_buffer *buffer,
unsigned long flags, int pc);

#define MAX_TRACER_SIZE 100
@@ -2621,7 +2622,7 @@ void trace_buffer_unlock_commit_regs(str
* two. They are not that meaningful.
*/
ftrace_trace_stack(tr, buffer, flags, regs ? 0 : STACK_SKIP, pc, regs);
- ftrace_trace_userstack(buffer, flags, pc);
+ ftrace_trace_userstack(tr, buffer, flags, pc);
}

/*
@@ -2936,13 +2937,14 @@ EXPORT_SYMBOL_GPL(trace_dump_stack);
static DEFINE_PER_CPU(int, user_stack_count);

static void
-ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
+ftrace_trace_userstack(struct trace_array *tr,
+ struct ring_buffer *buffer, unsigned long flags, int pc)
{
struct trace_event_call *call = &event_user_stack;
struct ring_buffer_event *event;
struct userstack_entry *entry;

- if (!(global_trace.trace_flags & TRACE_ITER_USERSTACKTRACE))
+ if (!(tr->trace_flags & TRACE_ITER_USERSTACKTRACE))
return;

/*
@@ -2981,7 +2983,8 @@ ftrace_trace_userstack(struct ring_buffe
preempt_enable();
}
#else /* CONFIG_USER_STACKTRACE_SUPPORT */
-static void ftrace_trace_userstack(struct ring_buffer *buffer,
+static void ftrace_trace_userstack(struct trace_array *tr,
+ struct ring_buffer *buffer,
unsigned long flags, int pc)
{
}