[v2,4/4] ftrace: Add arguments to function tracer

Message ID	20241223201542.415861522@goodmis.org (mailing list archive)
State	New
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 2F3431D61A1; Mon, 23 Dec 2024 20:14:50 +0000 (UTC) Message-ID: <20241223201542.415861522@goodmis.org> User-Agent: quilt/0.68 Date: Mon, 23 Dec 2024 15:13:51 -0500 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>, Sven Schnelle <svens@linux.ibm.com>, Paul Walmsley <paul.walmsley@sifive.com>, Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu>, Guo Ren <guoren@kernel.org>, Donglin Peng <dolinux.peng@gmail.com>, Zheng Yejian <zhengyejian@huaweicloud.com>, bpf@vger.kernel.org Subject: [PATCH v2 4/4] ftrace: Add arguments to function tracer References: <20241223201347.609298489@goodmis.org> Precedence: bulk MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8
Series	ftrace: Add function arguments to function tracers \| expand [v2,0/4] ftrace: Add function arguments to function tracers [v2,1/4] ftrace: Add print_function_args() [v2,2/4] ftrace: Add support for function argument to graph tracer [v2,3/4] ftrace: Have funcgraph-args take affect during tracing [v2,4/4] ftrace: Add arguments to function tracer

Context	Check	Description
netdev/tree_selection	success	Not a local patch, async

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index be62f0ea1814..3c0ffdcdcb7e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2897,13 +2897,16 @@ trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer, void trace_function(struct trace_array *tr, unsigned long ip, unsigned long - parent_ip, unsigned int trace_ctx) + parent_ip, unsigned int trace_ctx, struct ftrace_regs *fregs) { struct trace_buffer *buffer = tr->array_buffer.buffer; struct ring_buffer_event *event; struct ftrace_entry *entry; + int size = sizeof(*entry); - event = __trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry), + size += FTRACE_REGS_MAX_ARGS * !!fregs * sizeof(long); + + event = __trace_buffer_lock_reserve(buffer, TRACE_FN, size, trace_ctx); if (!event) return; @@ -2911,6 +2914,11 @@ trace_function(struct trace_array *tr, unsigned long ip, unsigned long entry->ip = ip; entry->parent_ip = parent_ip; + if (fregs) { + for (int i = 0; i < FTRACE_REGS_MAX_ARGS; i++) + entry->args[i] = ftrace_regs_get_argument(fregs, i); + } + if (static_branch_unlikely(&trace_function_exports_enabled)) ftrace_exports(event, TRACE_EXPORT_FUNCTION); __buffer_unlock_commit(buffer, event); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 6f67bbc17bed..3d4a5ec9ee55 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -685,7 +685,8 @@ unsigned long trace_total_entries(struct trace_array *tr); void trace_function(struct trace_array *tr, unsigned long ip, unsigned long parent_ip, - unsigned int trace_ctx); + unsigned int trace_ctx, + struct ftrace_regs *regs); void trace_graph_function(struct trace_array *tr, unsigned long ip, unsigned long parent_ip, diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index 254491b545c3..11288dc4f59b 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -61,8 +61,9 @@ FTRACE_ENTRY_REG(function, ftrace_entry, TRACE_FN, F_STRUCT( - __field_fn( unsigned long, ip ) - __field_fn( unsigned long, parent_ip ) + __field_fn( unsigned long, ip ) + __field_fn( unsigned long, parent_ip ) + __dynamic_array( unsigned long, args ) ), F_printk(" %ps <-- %ps", diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index d358c9935164..1f4f02df6f8c 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -25,6 +25,9 @@ static void function_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs); static void +function_args_trace_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs); +static void function_stack_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs); static void @@ -42,9 +45,10 @@ enum { TRACE_FUNC_NO_OPTS = 0x0, /* No flags set. */ TRACE_FUNC_OPT_STACK = 0x1, TRACE_FUNC_OPT_NO_REPEATS = 0x2, + TRACE_FUNC_OPT_ARGS = 0x4, /* Update this to next highest bit. */ - TRACE_FUNC_OPT_HIGHEST_BIT = 0x4 + TRACE_FUNC_OPT_HIGHEST_BIT = 0x8 }; #define TRACE_FUNC_OPT_MASK (TRACE_FUNC_OPT_HIGHEST_BIT - 1) @@ -114,6 +118,8 @@ static ftrace_func_t select_trace_function(u32 flags_val) switch (flags_val & TRACE_FUNC_OPT_MASK) { case TRACE_FUNC_NO_OPTS: return function_trace_call; + case TRACE_FUNC_OPT_ARGS: + return function_args_trace_call; case TRACE_FUNC_OPT_STACK: return function_stack_trace_call; case TRACE_FUNC_OPT_NO_REPEATS: @@ -220,7 +226,34 @@ function_trace_call(unsigned long ip, unsigned long parent_ip, data = this_cpu_ptr(tr->array_buffer.data); if (!atomic_read(&data->disabled)) - trace_function(tr, ip, parent_ip, trace_ctx); + trace_function(tr, ip, parent_ip, trace_ctx, NULL); + + ftrace_test_recursion_unlock(bit); +} + +static void +function_args_trace_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs) +{ + struct trace_array *tr = op->private; + struct trace_array_cpu *data; + unsigned int trace_ctx; + int bit; + int cpu; + + if (unlikely(!tr->function_enabled)) + return; + + bit = ftrace_test_recursion_trylock(ip, parent_ip); + if (bit < 0) + return; + + trace_ctx = tracing_gen_ctx(); + + cpu = smp_processor_id(); + data = per_cpu_ptr(tr->array_buffer.data, cpu); + if (!atomic_read(&data->disabled)) + trace_function(tr, ip, parent_ip, trace_ctx, fregs); ftrace_test_recursion_unlock(bit); } @@ -270,7 +303,7 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip, if (likely(disabled == 1)) { trace_ctx = tracing_gen_ctx_flags(flags); - trace_function(tr, ip, parent_ip, trace_ctx); + trace_function(tr, ip, parent_ip, trace_ctx, NULL); #ifdef CONFIG_UNWINDER_FRAME_POINTER if (ftrace_pids_enabled(op)) skip++; @@ -351,7 +384,7 @@ function_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip, trace_ctx = tracing_gen_ctx_flags(flags); process_repeats(tr, ip, parent_ip, last_info, trace_ctx); - trace_function(tr, ip, parent_ip, trace_ctx); + trace_function(tr, ip, parent_ip, trace_ctx, NULL); out: ftrace_test_recursion_unlock(bit); @@ -391,7 +424,7 @@ function_stack_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip, trace_ctx = tracing_gen_ctx_flags(flags); process_repeats(tr, ip, parent_ip, last_info, trace_ctx); - trace_function(tr, ip, parent_ip, trace_ctx); + trace_function(tr, ip, parent_ip, trace_ctx, NULL); __trace_stack(tr, trace_ctx, STACK_SKIP); } @@ -405,6 +438,9 @@ static struct tracer_opt func_opts[] = { { TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) }, #endif { TRACER_OPT(func-no-repeats, TRACE_FUNC_OPT_NO_REPEATS) }, +#ifdef CONFIG_FUNCTION_TRACE_ARGS + { TRACER_OPT(func-args, TRACE_FUNC_OPT_ARGS) }, +#endif { } /* Always set a last empty entry */ }; diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 504de7a05498..68ce152dbb8c 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -150,7 +150,7 @@ irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip, trace_ctx = tracing_gen_ctx_flags(flags); - trace_function(tr, ip, parent_ip, trace_ctx); + trace_function(tr, ip, parent_ip, trace_ctx, fregs); atomic_dec(&data->disabled); } @@ -280,7 +280,7 @@ __trace_function(struct trace_array *tr, if (is_graph(tr)) trace_graph_function(tr, ip, parent_ip, trace_ctx); else - trace_function(tr, ip, parent_ip, trace_ctx); + trace_function(tr, ip, parent_ip, trace_ctx, NULL); } #else diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 40d6c7a9e0c4..aed6758416a0 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -1079,12 +1079,15 @@ enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags, } static void print_fn_trace(struct trace_seq *s, unsigned long ip, - unsigned long parent_ip, long delta, int flags) + unsigned long parent_ip, long delta, + unsigned long *args, int flags) { ip += delta; parent_ip += delta; seq_print_ip_sym(s, ip, flags); + if (args) + print_function_args(s, args, ip); if ((flags & TRACE_ITER_PRINT_PARENT) && parent_ip) { trace_seq_puts(s, " <-"); @@ -1098,10 +1101,19 @@ static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags, { struct ftrace_entry *field; struct trace_seq *s = &iter->seq; + unsigned long *args; + int args_size; trace_assign_type(field, iter->ent); - print_fn_trace(s, field->ip, field->parent_ip, iter->tr->text_delta, flags); + args_size = iter->ent_size - offsetof(struct ftrace_entry, args); + if (args_size >= FTRACE_REGS_MAX_ARGS * sizeof(long)) + args = field->args; + else + args = NULL; + + print_fn_trace(s, field->ip, field->parent_ip, iter->tr->text_delta, + args, flags); trace_seq_putc(s, '\n'); return trace_handle_return(s); @@ -1774,7 +1786,7 @@ trace_func_repeats_print(struct trace_iterator *iter, int flags, trace_assign_type(field, iter->ent); - print_fn_trace(s, field->ip, field->parent_ip, iter->tr->text_delta, flags); + print_fn_trace(s, field->ip, field->parent_ip, iter->tr->text_delta, NULL, flags); trace_seq_printf(s, " (repeats: %u, last_ts:", field->count); trace_print_time(s, iter, iter->ts - FUNC_REPEATS_GET_DELTA_TS(field)); diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 8165382a174a..19b0205b91dd 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -226,7 +226,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, return; local_irq_save(flags); - trace_function(tr, ip, parent_ip, trace_ctx); + trace_function(tr, ip, parent_ip, trace_ctx, fregs); local_irq_restore(flags); atomic_dec(&data->disabled); @@ -311,7 +311,7 @@ __trace_function(struct trace_array *tr, if (is_graph(tr)) trace_graph_function(tr, ip, parent_ip, trace_ctx); else - trace_function(tr, ip, parent_ip, trace_ctx); + trace_function(tr, ip, parent_ip, trace_ctx, NULL); } static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set)

[v2,4/4] ftrace: Add arguments to function tracer

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