The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From bcee5278958802b40ee8b26679155a6d9231783e Mon Sep 17 00:00:00 2001

From: "Steven Rostedt (VMware)" rostedt@goodmis.org Date: Fri, 4 Dec 2020 16:36:16 -0500 Subject: [PATCH] tracing: Fix userstacktrace option for instances

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

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7d53c5bdea3e..06134189e9a7 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -163,7 +163,8 @@ static union trace_eval_map_item *trace_eval_maps; #endif /* CONFIG_TRACE_EVAL_MAP_FILE */

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

#define MAX_TRACER_SIZE 100 @@ -2870,7 +2871,7 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr, * 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); }

/* @@ -3056,13 +3057,14 @@ EXPORT_SYMBOL_GPL(trace_dump_stack); static DEFINE_PER_CPU(int, user_stack_count);

static void -ftrace_trace_userstack(struct trace_buffer *buffer, unsigned long flags, int pc) +ftrace_trace_userstack(struct trace_array *tr, + struct trace_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;

/* @@ -3101,7 +3103,8 @@ ftrace_trace_userstack(struct trace_buffer *buffer, unsigned long flags, int pc) preempt_enable(); } #else /* CONFIG_USER_STACKTRACE_SUPPORT */ -static void ftrace_trace_userstack(struct trace_buffer *buffer, +static void ftrace_trace_userstack(struct trace_array *tr, + struct trace_buffer *buffer, unsigned long flags, int pc) { }