[RFC,08/32] ftrace: Allow function_graph tracer to be enabled in instances

Message ID	169920048725.482486.18063340929679228603.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State	Superseded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 273AFF9DA; Sun, 5 Nov 2023 16:08:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="vMp9EDFB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02A2DC433C8; Sun, 5 Nov 2023 16:08:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699200494; bh=Cg6ntUmQC2rEjvbKG7mMJ57xA499xXXa/ZvQe5xjpag=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vMp9EDFB/dc+TrbNZAz3O4HAqzYXQkw1wC1bjf7QikvwEvrcZRGeJhyRVbJ0cZ2Mv 8OjPHi0njrY+D5QU7M2LLbR7Eoo3rJFAJ52i/qExMyA6AYEYQiyR++5M9lThZDyTmy URVMLMLDa/niqzCZwrEygDjpWPv+u8qAj8IWk0ujS5q03vkKNccNQMRPQZRVs2p7u9 m7N22Ylgq5SUUwHTAEM14HwU2zaTJVX+d4qb6GQ+Qh4Qf+X68/Kte7sLRtCeTwJZHR khtg1szGP2qNWSbBLU9+90gmt82UNQqeNoldSd2zWUv94p7Bagr/W8NIUDxAaNqzlE FJAQM7r8WER1Q== 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: [RFC PATCH 08/32] ftrace: Allow function_graph tracer to be enabled in instances Date: Mon, 6 Nov 2023 01:08:07 +0900 Message-Id: <169920048725.482486.18063340929679228603.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <169920038849.482486.15796387219966662967.stgit@devnote2> References: <169920038849.482486.15796387219966662967.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: <linux-trace-kernel.vger.kernel.org> List-Subscribe: <mailto:linux-trace-kernel+subscribe@vger.kernel.org> List-Unsubscribe: <mailto:linux-trace-kernel+unsubscribe@vger.kernel.org> 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 [RFC,00/32] tracing: fprobe: function_graph: Multi-function graph and fprobe on fgraph [RFC,01/32] seq_buf: Export seq_buf_puts() [RFC,02/32] function_graph: Convert ret_stack to a series of longs [RFC,03/32] fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long [RFC,04/32] function_graph: Add an array structure that will allow multiple callbacks [RFC,05/32] function_graph: Allow multiple users to attach to function graph [RFC,06/32] function_graph: Remove logic around ftrace_graph_entry and return [RFC,07/32] ftrace/function_graph: Pass fgraph_ops to function graph callbacks [RFC,08/32] ftrace: Allow function_graph tracer to be enabled in instances [RFC,09/32] ftrace: Allow ftrace startup flags exist without dynamic ftrace [RFC,10/32] function_graph: Have the instances use their own ftrace_ops for filtering [RFC,11/32] function_graph: Add "task variables" per task for fgraph_ops [RFC,12/32] function_graph: Move set_graph_function tests to shadow stack global var [RFC,13/32] function_graph: Move graph depth stored data to shadow stack global var [RFC,14/32] function_graph: Move graph notrace bit to shadow stack global var [RFC,15/32] function_graph: Implement fgraph_reserve_data() and fgraph_retrieve_data() [RFC,16/32] function_graph: Add selftest for passing local variables [RFC,17/32] function_graph: Fix to update curr_ret_stack with ARRAY entry size [RFC,18/32] function_graph: Fix to initalize ftrace_ops for fgraph with ftrace_graph_func [RFC,19/32] function_graph: Fix to check the return value of ftrace_pop_return_trace() [RFC,20/32] function_graph: Pass the size of reserved data when retrieving it [RFC,21/32] function_graph: Expand the max reserved data size [RFC,22/32] function_graph: Add a new entry handler with parent_ip and ftrace_regs [RFC,23/32] function_graph: Add a new exit handler with parent_ip and ftrace_regs [RFC,24/32] x86/ftrace: Enable HAVE_FUNCTION_GRAPH_FREGS [RFC,25/32] fprobe: Use ftrace_regs in fprobe entry handler [RFC,26/32] fprobe: Use ftrace_regs in fprobe exit handler [RFC,27/32] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs [RFC,28/32] tracing: Add ftrace_fill_perf_regs() for perf event [RFC,29/32] fprobe: Rewrite fprobe on function-graph tracer [RFC,30/32] tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS [RFC,31/32] bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled [RFC,32/32] Documentation: probes: Update fprobe on function-graph tracer

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index ff32a0ec57aa..4ad587b3525e 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -1044,6 +1044,7 @@ 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; }; /* diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 7ff5c454622a..83fbfb7b48f8 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -7319,6 +7319,7 @@ __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 ada49bf1fbc8..73fe789ba143 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -395,6 +395,9 @@ 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; @@ -883,6 +886,9 @@ 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; @@ -995,6 +1001,12 @@ 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..e05f7335525c 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);

[RFC,08/32] ftrace: Allow function_graph tracer to be enabled in instances

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