[v8,10/35] ftrace: Allow function_graph tracer to be enabled in instances

Message ID	170887421299.564249.17993706602498179176.stgit@devnote2 (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State	Superseded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 B0A4A1429B; Sun, 25 Feb 2024 15:16:58 +0000 (UTC) From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> To: Alexei Starovoitov <alexei.starovoitov@gmail.com>, Steven Rostedt <rostedt@goodmis.org>, Florent Revest <revest@chromium.org> Cc: linux-trace-kernel@vger.kernel.org, LKML <linux-kernel@vger.kernel.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>, Mark Rutland <mark.rutland@arm.com>, Peter Zijlstra <peterz@infradead.org>, Thomas Gleixner <tglx@linutronix.de>, Guo Ren <guoren@kernel.org> Subject: [PATCH v8 10/35] ftrace: Allow function_graph tracer to be enabled in instances Date: Mon, 26 Feb 2024 00:16:53 +0900 Message-Id: <170887421299.564249.17993706602498179176.stgit@devnote2> In-Reply-To: <170887410337.564249.6360118840946697039.stgit@devnote2> References: <170887410337.564249.6360118840946697039.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit
Series	tracing: fprobe: function_graph: Multi-function graph and fprobe on fgraph \| expand [v8,00/35] tracing: fprobe: function_graph: Multi-function graph and fprobe on fgraph [v8,01/35] tracing: Add a comment about ftrace_regs definition [v8,02/35] tracing: Rename ftrace_regs_return_value to ftrace_regs_get_return_value [v8,03/35] x86: tracing: Add ftrace_regs definition in the header [v8,04/35] function_graph: Convert ret_stack to a series of longs [v8,05/35] fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long [v8,06/35] function_graph: Add an array structure that will allow multiple callbacks [v8,07/35] function_graph: Allow multiple users to attach to function graph [v8,08/35] function_graph: Remove logic around ftrace_graph_entry and return [v8,09/35] ftrace/function_graph: Pass fgraph_ops to function graph callbacks [v8,10/35] ftrace: Allow function_graph tracer to be enabled in instances [v8,11/35] ftrace: Allow ftrace startup flags exist without dynamic ftrace [v8,12/35] function_graph: Have the instances use their own ftrace_ops for filtering [v8,13/35] function_graph: Use a simple LRU for fgraph_array index number [v8,14/35] function_graph: Add "task variables" per task for fgraph_ops [v8,15/35] function_graph: Move set_graph_function tests to shadow stack global var [v8,16/35] function_graph: Move graph depth stored data to shadow stack global var [v8,17/35] function_graph: Move graph notrace bit to shadow stack global var [v8,18/35] function_graph: Implement fgraph_reserve_data() and fgraph_retrieve_data() [v8,19/35] function_graph: Add selftest for passing local variables [v8,20/35] ftrace: Add multiple fgraph storage selftest [v8,21/35] function_graph: Pass ftrace_regs to entryfunc [v8,22/35] function_graph: Replace fgraph_ret_regs with ftrace_regs [v8,23/35] function_graph: Pass ftrace_regs to retfunc [v8,24/35] fprobe: Use ftrace_regs in fprobe entry handler [v8,25/35] fprobe: Use ftrace_regs in fprobe exit handler [v8,26/35] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs [v8,27/35] tracing: Add ftrace_fill_perf_regs() for perf event [v8,28/35] tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS [v8,29/35] bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled [v8,30/35] ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC [v8,31/35] fprobe: Rewrite fprobe on function-graph tracer [v8,32/35] tracing/fprobe: Remove nr_maxactive from fprobe [v8,33/35] selftests: ftrace: Remove obsolate maxactive syntax check [v8,34/35] selftests/ftrace: Add a test case for repeating register/unregister fprobe [v8,35/35] Documentation: probes: Update fprobe on function-graph tracer

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index a71870183f1b..17aa123d134e 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -1070,6 +1070,7 @@ 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 b063ab2d2b1f..a720dd7cf290 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -7323,6 +7323,7 @@ __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 7d838a32bce5..3b39936c9375 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -396,6 +396,9 @@ 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; @@ -680,7 +683,6 @@ 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); @@ -891,6 +893,9 @@ 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; @@ -1003,6 +1008,12 @@ 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 914331d8242c..f0758afa2f7d 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

[v8,10/35] ftrace: Allow function_graph tracer to be enabled in instances

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