FAILED: patch "[PATCH] tracing: Disable snapshot buffer when stopping instance" failed to apply to 4.19-stable tree
Subsystems (2)
[email protected]
maintainerThe patch below does not apply to the 4.19-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 <[email protected]>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x b538bf7d0ec11ca49f536dfda742a5f6db90a798
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023120909-tutu-fabulous-be5d@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..
Possible dependencies:
b538bf7d0ec1 ("tracing: Disable snapshot buffer when stopping instance tracers") 13292494379f ("tracing: Make struct ring_buffer less ambiguous")1c5eb4481e01 ("tracing: Rename trace_buffer to array_buffer")2d6425af6116 ("tracing: Declare newly exported APIs in include/linux/trace.h") a47b53e95acc ("tracing: Rename tracing_reset() to tracing_reset_cpu()")46cc0b44428d ("tracing/snapshot: Resize spare buffer if size changed")d2d8b146043a ("Merge tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b538bf7d0ec11ca49f536dfda742a5f6db90a798 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (Google)" <[email protected]>
Date: Tue, 5 Dec 2023 16:52:11 -0500
Subject: [PATCH] tracing: Disable snapshot buffer when stopping instance
tracers
It use to be that only the top level instance had a snapshot buffer (for latency tracers like wakeup and irqsoff). When stopping a tracer in an instance would not disable the snapshot buffer. This could have some unintended consequences if the irqsoff tracer is enabled.
Consolidate the tracing_start/stop() with tracing_start/stop_tr() so that all instances behave the same. The tracing_start/stop() functions will just call their respective tracing_start/stop_tr() with the global_array passed in.
kernel/trace/trace.c +53 -95
@@ -2360,49 +2360,6 @@ int is_tracing_stopped(void)return global_trace.stop_count; } -/** -* tracing_start - quick start of the tracer -* -* If tracing is enabled but was stopped by tracing_stop, -* this will start the tracer back up. -*/ -void tracing_start (void ) -{ -struct trace_buffer *buffer; -unsigned long flags; - -if (tracing_disabled) -return ; - -raw_spin_lock_irqsave (&global_trace.start_lock, flags); -if (--global_trace.stop_count) { -if (global_trace.stop_count <0 ) { -/* Someone screwed up their debugging */ -WARN_ON_ONCE (1 ); - global_trace.stop_count =0 ; - } - goto out; - } - -/* Prevent the buffers from switching */ -arch_spin_lock (&global_trace.max_lock); - - buffer = global_trace.array_buffer.buffer; -if (buffer) -ring_buffer_record_enable (buffer); - -#ifdef CONFIG_TRACER_MAX_TRACE - buffer = global_trace.max_buffer.buffer; -if (buffer) -ring_buffer_record_enable (buffer); -#endif - -arch_spin_unlock (&global_trace.max_lock); - - out: -raw_spin_unlock_irqrestore (&global_trace.start_lock, flags); -} -static void tracing_start_tr (struct trace_array *tr) {struct trace_buffer *buffer;
@@ -2411,25 +2368,70 @@ static void tracing_start_tr(struct trace_array *tr)if (tracing_disabled)return ; -/* If global, we need to also start the max tracer */ -if (tr->flags &TRACE_ARRAY_FL_GLOBAL ) -return tracing_start (); -raw_spin_lock_irqsave (&tr->start_lock, flags); -if (--tr->stop_count) { -if (tr->stop_count <0 ) { +if (WARN_ON_ONCE (tr->stop_count <0 )) {/* Someone screwed up their debugging */ -WARN_ON_ONCE (1 ); tr->stop_count =0 ; } goto out; } +/* Prevent the buffers from switching */ +arch_spin_lock (&tr->max_lock); + buffer = tr->array_buffer.buffer;if (buffer)ring_buffer_record_enable (buffer); +#ifdef CONFIG_TRACER_MAX_TRACE + buffer = tr->max_buffer.buffer; +if (buffer) +ring_buffer_record_enable (buffer); +#endif + +arch_spin_unlock (&tr->max_lock); + + out: +raw_spin_unlock_irqrestore (&tr->start_lock, flags); +} + +/** +* tracing_start - quick start of the tracer +* +* If tracing is enabled but was stopped by tracing_stop, +* this will start the tracer back up. +*/ +void tracing_start (void ) + +{ +return tracing_start_tr (&global_trace); +} + +static void tracing_stop_tr (struct trace_array *tr) +{ +struct trace_buffer *buffer; +unsigned long flags; + +raw_spin_lock_irqsave (&tr->start_lock, flags); +if (tr->stop_count++) + goto out; + +/* Prevent the buffers from switching */ +arch_spin_lock (&tr->max_lock); + + buffer = tr->array_buffer.buffer; +if (buffer) +ring_buffer_record_disable (buffer); + +#ifdef CONFIG_TRACER_MAX_TRACE + buffer = tr->max_buffer.buffer; +if (buffer) +ring_buffer_record_disable (buffer); +#endif + +arch_spin_unlock (&tr->max_lock); + out:raw_spin_unlock_irqrestore (&tr->start_lock, flags); }
@@ -2442,51 +2444,7 @@ static void tracing_start_tr(struct trace_array *tr)*/ void tracing_stop (void ) { -struct trace_buffer *buffer; -unsigned long flags; - -raw_spin_lock_irqsave (&global_trace.start_lock, flags); -if (global_trace.stop_count++) - goto out; - -/* Prevent the buffers from switching */ -arch_spin_lock (&global_trace.max_lock); - - buffer = global_trace.array_buffer.buffer; -if (buffer) -ring_buffer_record_disable (buffer); - -#ifdef CONFIG_TRACER_MAX_TRACE - buffer = global_trace.max_buffer.buffer; -if (buffer) -ring_buffer_record_disable (buffer); -#endif - -arch_spin_unlock (&global_trace.max_lock); - - out: -raw_spin_unlock_irqrestore (&global_trace.start_lock, flags); -} - -static void tracing_stop_tr (struct trace_array *tr) -{ -struct trace_buffer *buffer; -unsigned long flags; - -/* If global, we need to also stop the max tracer */ -if (tr->flags &TRACE_ARRAY_FL_GLOBAL ) -return tracing_stop (); - -raw_spin_lock_irqsave (&tr->start_lock, flags); -if (tr->stop_count++) - goto out; - - buffer = tr->array_buffer.buffer; -if (buffer) -ring_buffer_record_disable (buffer); - - out: -raw_spin_unlock_irqrestore (&tr->start_lock, flags); +return tracing_stop_tr (&global_trace); }static int trace_save_cmdline (struct task_struct *tsk)