[v3,08/27] ftrace: Allow function_graph tracer to be enabled in instances

Message ID	20240603190822.190630762@goodmis.org (mailing list archive)
State	Superseded
Headers	show Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 86BD313B798; Mon, 3 Jun 2024 19:07:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717441631; cv=none; b=m8mcD1klYi1keCEbNEF71/RF+hBAlFCrk5eg/imJiaQP5oZ1bqrrB3QasglDtu+TfbjDPNqXksWr7u0HX6OpjJxjJACnNDjJMaivSpyisIJ8J53c98b4gzl9R0XB/SVMQoYxPQSczjpL+71ok66DCQdDgTYHMC1ysH0VpeHwxxM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717441631; c=relaxed/simple; bh=PYm9MD8SRbasVRSO3SD5PaTsK2kjEHK5Rg2egyMye/k=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=A+8ek9XbWAG5iy/qDy+vSpyd+KjMaqqSGUCI/OMaek2v/mOOE7D/TR07zWlpzCeMDOBTmBX9kxCF3L8r0y7r4meFXVQ4bCaALuyOEbxMJJANp693cSl84Yf/yzsGPFSGy8YOB2enQWQnNjm0Zii0ZVbqlgLG4jCytcMBvCG1ias= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5C61FC4DDF9; Mon, 3 Jun 2024 19:07:11 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from <rostedt@goodmis.org>) id 1sED2c-00000009Tpv-1NWN; Mon, 03 Jun 2024 15:08:22 -0400 Message-ID: <20240603190822.190630762@goodmis.org> User-Agent: quilt/0.68 Date: Mon, 03 Jun 2024 15:07:12 -0400 From: Steven Rostedt <rostedt@goodmis.org> To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Mathieu Desnoyers <mathieu.desnoyers@efficios.com>, Andrew Morton <akpm@linux-foundation.org>, Alexei Starovoitov <alexei.starovoitov@gmail.com>, Florent Revest <revest@chromium.org>, Martin KaFai Lau <martin.lau@linux.dev>, bpf <bpf@vger.kernel.org>, Sven Schnelle <svens@linux.ibm.com>, Alexei Starovoitov <ast@kernel.org>, Jiri Olsa <jolsa@kernel.org>, Arnaldo Carvalho de Melo <acme@kernel.org>, Daniel Borkmann <daniel@iogearbox.net>, Alan Maguire <alan.maguire@oracle.com>, Peter Zijlstra <peterz@infradead.org>, Thomas Gleixner <tglx@linutronix.de>, Guo Ren <guoren@kernel.org> Subject: [PATCH v3 08/27] ftrace: Allow function_graph tracer to be enabled in instances References: <20240603190704.663840775@goodmis.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: <bpf.vger.kernel.org> List-Subscribe: <mailto:bpf+subscribe@vger.kernel.org> List-Unsubscribe: <mailto:bpf+unsubscribe@vger.kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8
Series	[v3,01/27] function_graph: Convert ret_stack to a series of longs \| expand [v3,01/27] function_graph: Convert ret_stack to a series of longs [v3,02/27] fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long [v3,03/27] function_graph: Add an array structure that will allow multiple callbacks [v3,04/27] function_graph: Allow multiple users to attach to function graph [v3,05/27] function_graph: Handle tail calls for stack unwinding [v3,06/27] function_graph: Remove logic around ftrace_graph_entry and return [v3,07/27] ftrace/function_graph: Pass fgraph_ops to function graph callbacks [v3,08/27] ftrace: Allow function_graph tracer to be enabled in instances [v3,09/27] ftrace: Allow ftrace startup flags to exist without dynamic ftrace [v3,10/27] ftrace: Add subops logic to allow one ops to manage many [v3,11/27] ftrace: Allow subops filtering to be modified [v3,12/27] function_graph: Have the instances use their own ftrace_ops for filtering [v3,13/27] function_graph: Add pid tracing back to function graph tracer [v3,14/27] function_graph: Use a simple LRU for fgraph_array index number [v3,15/27] function_graph: Add "task variables" per task for fgraph_ops [v3,16/27] function_graph: Move set_graph_function tests to shadow stack global var [v3,17/27] function_graph: Move graph depth stored data to shadow stack global var [v3,18/27] function_graph: Move graph notrace bit to shadow stack global var [v3,19/27] function_graph: Implement fgraph_reserve_data() and fgraph_retrieve_data() [v3,20/27] function_graph: Add selftest for passing local variables [v3,21/27] ftrace: Add multiple fgraph storage selftest [v3,22/27] function_graph: Use for_each_set_bit() in __ftrace_return_to_handler() [v3,23/27] function_graph: Use bitmask to loop on fgraph entry [v3,24/27] function_graph: Use static_call and branch to optimize entry function [v3,25/27] function_graph: Use static_call and branch to optimize return function [v3,26/27] selftests/ftrace: Add function_graph tracer to func-filter-pid test [v3,27/27] selftests/ftrace: Add fgraph-multi.tc test

Context	Check	Description
netdev/tree_selection	success	Not a local patch

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 4d817b85ac0d..fd656e6d6b7c 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -1042,6 +1042,7 @@ extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace, struct fgraph struct fgraph_ops { trace_func_graph_ent_t entryfunc; trace_func_graph_ret_t retfunc; + void *private; int idx; }; diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index d18387c0642d..b85f00b0ffe7 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -7327,6 +7327,7 @@ __init void ftrace_init_global_array_ops(struct trace_array *tr) tr->ops = &global_ops; tr->ops->private = tr; ftrace_init_trace_array(tr); + init_array_fgraph_ops(tr); } void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 2575ec243350..a5070f9b977b 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -397,6 +397,9 @@ struct trace_array { struct ftrace_ops *ops; struct trace_pid_list __rcu *function_pids; struct trace_pid_list __rcu *function_no_pids; +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + struct fgraph_ops *gops; +#endif #ifdef CONFIG_DYNAMIC_FTRACE /* All of these are protected by the ftrace_lock */ struct list_head func_probes; @@ -681,7 +684,6 @@ void print_trace_header(struct seq_file *m, struct trace_iterator *iter); void trace_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops); int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops); -void set_graph_array(struct trace_array *tr); void tracing_start_cmdline_record(void); void tracing_stop_cmdline_record(void); @@ -892,6 +894,9 @@ extern int __trace_graph_entry(struct trace_array *tr, extern void __trace_graph_return(struct trace_array *tr, struct ftrace_graph_ret *trace, unsigned int trace_ctx); +extern void init_array_fgraph_ops(struct trace_array *tr); +extern int allocate_fgraph_ops(struct trace_array *tr); +extern void free_fgraph_ops(struct trace_array *tr); #ifdef CONFIG_DYNAMIC_FTRACE extern struct ftrace_hash __rcu *ftrace_graph_hash; @@ -1004,6 +1009,12 @@ print_graph_function_flags(struct trace_iterator *iter, u32 flags) { return TRACE_TYPE_UNHANDLED; } +static inline void init_array_fgraph_ops(struct trace_array *tr) { } +static inline int allocate_fgraph_ops(struct trace_array *tr) +{ + return 0; +} +static inline void free_fgraph_ops(struct trace_array *tr) { } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ extern struct list_head ftrace_pids; diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index 9f1bfbe105e8..8e8da0d0ee52 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -80,6 +80,7 @@ void ftrace_free_ftrace_ops(struct trace_array *tr) int ftrace_create_function_files(struct trace_array *tr, struct dentry *parent) { + int ret; /* * The top level array uses the "global_ops", and the files are * created on boot up. @@ -90,6 +91,12 @@ int ftrace_create_function_files(struct trace_array *tr, if (!tr->ops) return -EINVAL; + ret = allocate_fgraph_ops(tr); + if (ret) { + kfree(tr->ops); + return ret; + } + ftrace_create_filter_files(tr->ops, parent); return 0; @@ -99,6 +106,7 @@ void ftrace_destroy_function_files(struct trace_array *tr) { ftrace_destroy_filter_files(tr->ops); ftrace_free_ftrace_ops(tr); + free_fgraph_ops(tr); } static ftrace_func_t select_trace_function(u32 flags_val) diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index b7b142b65299..9ccc904a7703 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -83,8 +83,6 @@ static struct tracer_flags tracer_flags = { .opts = trace_opts }; -static struct trace_array *graph_array; - /* * DURATION column is being also used to display IRQ signs, * following values are used by print_graph_irq and others @@ -132,7 +130,7 @@ static inline int ftrace_graph_ignore_irqs(void) int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops) { - struct trace_array *tr = graph_array; + struct trace_array *tr = gops->private; struct trace_array_cpu *data; unsigned long flags; unsigned int trace_ctx; @@ -242,7 +240,7 @@ void __trace_graph_return(struct trace_array *tr, void trace_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops) { - struct trace_array *tr = graph_array; + struct trace_array *tr = gops->private; struct trace_array_cpu *data; unsigned long flags; unsigned int trace_ctx; @@ -268,15 +266,6 @@ void trace_graph_return(struct ftrace_graph_ret *trace, local_irq_restore(flags); } -void set_graph_array(struct trace_array *tr) -{ - graph_array = tr; - - /* Make graph_array visible before we start tracing */ - - smp_mb(); -} - static void trace_graph_thresh_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops) { @@ -294,25 +283,53 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace, trace_graph_return(trace, gops); } -static struct fgraph_ops funcgraph_thresh_ops = { - .entryfunc = &trace_graph_entry, - .retfunc = &trace_graph_thresh_return, -}; - static struct fgraph_ops funcgraph_ops = { .entryfunc = &trace_graph_entry, .retfunc = &trace_graph_return, }; +int allocate_fgraph_ops(struct trace_array *tr) +{ + struct fgraph_ops *gops; + + gops = kzalloc(sizeof(*gops), GFP_KERNEL); + if (!gops) + return -ENOMEM; + + gops->entryfunc = &trace_graph_entry; + gops->retfunc = &trace_graph_return; + + tr->gops = gops; + gops->private = tr; + return 0; +} + +void free_fgraph_ops(struct trace_array *tr) +{ + kfree(tr->gops); +} + +__init void init_array_fgraph_ops(struct trace_array *tr) +{ + tr->gops = &funcgraph_ops; + funcgraph_ops.private = tr; +} + static int graph_trace_init(struct trace_array *tr) { int ret; - set_graph_array(tr); + tr->gops->entryfunc = trace_graph_entry; + if (tracing_thresh) - ret = register_ftrace_graph(&funcgraph_thresh_ops); + tr->gops->retfunc = trace_graph_thresh_return; else - ret = register_ftrace_graph(&funcgraph_ops); + tr->gops->retfunc = trace_graph_return; + + /* Make gops functions are visible before we start tracing */ + smp_mb(); + + ret = register_ftrace_graph(tr->gops); if (ret) return ret; tracing_start_cmdline_record(); @@ -323,10 +340,7 @@ static int graph_trace_init(struct trace_array *tr) static void graph_trace_reset(struct trace_array *tr) { tracing_stop_cmdline_record(); - if (tracing_thresh) - unregister_ftrace_graph(&funcgraph_thresh_ops); - else - unregister_ftrace_graph(&funcgraph_ops); + unregister_ftrace_graph(tr->gops); } static int graph_trace_update_thresh(struct trace_array *tr) @@ -1365,6 +1379,7 @@ static struct tracer graph_trace __tracer_data = { .print_header = print_graph_headers, .flags = &tracer_flags, .set_flag = func_graph_set_flag, + .allow_instances = true, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_function_graph, #endif diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 56f269c0560a..f8f55fd79e53 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -813,7 +813,7 @@ trace_selftest_startup_function_graph(struct tracer *trace, * to detect and recover from possible hangs */ tracing_reset_online_cpus(&tr->array_buffer); - set_graph_array(tr); + fgraph_ops.private = tr; ret = register_ftrace_graph(&fgraph_ops); if (ret) { warn_failed_init_tracer(trace, ret); @@ -856,7 +856,7 @@ trace_selftest_startup_function_graph(struct tracer *trace, cond_resched(); tracing_reset_online_cpus(&tr->array_buffer); - set_graph_array(tr); + fgraph_ops.private = tr; /* * Some archs *cough*PowerPC*cough* add characters to the

[v3,08/27] ftrace: Allow function_graph tracer to be enabled in instances

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