[PATCH 4.19 33/39] tracing: Fix userstacktrace option for instances

From: Greg Kroah-Hartman
Date: Thu Dec 10 2020 - 09:37:43 EST


From: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>

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@xxxxxxxxxxxxxxx
Fixes: 16270145ce6b ("tracing: Add trace options for core options to instances")
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
kernel/trace/trace.c | 7 ++++---
kernel/trace/trace.h | 6 ++++--
2 files changed, 8 insertions(+), 5 deletions(-)

--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2416,7 +2416,7 @@ 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);
}

/*
@@ -2736,14 +2736,15 @@ void trace_dump_stack(int skip)
static DEFINE_PER_CPU(int, user_stack_count);

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;
struct stack_trace trace;

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

/*
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -745,13 +745,15 @@ void update_max_tr_single(struct trace_a
#endif /* CONFIG_TRACER_MAX_TRACE */

#ifdef CONFIG_STACKTRACE
-void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
+void ftrace_trace_userstack(struct trace_array *tr,
+ struct ring_buffer *buffer, unsigned long flags,
int pc);

void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
int pc);
#else
-static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
+static inline void ftrace_trace_userstack(struct trace_array *tr,
+ struct ring_buffer *buffer,
unsigned long flags, int pc)
{
}