From nobody Wed Dec 17 00:19:37 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 08B95C4167B for ; Fri, 8 Dec 2023 10:38:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1573765AbjLHKiT (ORCPT ); Fri, 8 Dec 2023 05:38:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1573667AbjLHKiI (ORCPT ); Fri, 8 Dec 2023 05:38:08 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B1C7213B for ; Fri, 8 Dec 2023 02:30:27 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4E75C433C7; Fri, 8 Dec 2023 10:30:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1702031426; bh=E6nu5gsbftq0MW8we9W5Y+vMqoODRszc8WZZUgWBgbk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gO7ms5ahGRlRQun4j8LDWsK5RJkD8ioWRysOiRukBnoxwH6F5gCM66iuCL+g1j+h3 DZTcp2r9YtjkP44gk1YNMa7WL2qC1KXg82dTqadjY9NVvWku3r41XhIMdbzfbC1TGl dHbAVcnMvnj33Mf9b29oo6JihCkYmiqBeMvD08g+7zdR5eWayVgNfUUUxMiupm6q7Y 9Mmh2NdDPX/11M/V4jYUp+L/WYCzKsItB30cb3ax8B/QxycOBW4IK5/ITIEUvRr42C 43xZEubqx3LVM60BzbJ7KEocR5nZhGs093sIHGtFemHNf9y3OgeKUIEDvx+yepqHH2 kOAexL9qbLYyg== From: "Masami Hiramatsu (Google)" To: Alexei Starovoitov , Steven Rostedt , Florent Revest Cc: linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Sven Schnelle , Alexei Starovoitov , Jiri Olsa , Arnaldo Carvalho de Melo , Daniel Borkmann , Alan Maguire , Mark Rutland , Peter Zijlstra , Thomas Gleixner , Guo Ren Subject: [PATCH v4 30/33] tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS Date: Fri, 8 Dec 2023 19:30:20 +0900 Message-Id: <170203141980.579004.5047004830423702367.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <170203105427.579004.8033550792660734570.stgit@devnote2> References: <170203105427.579004.8033550792660734570.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Masami Hiramatsu (Google) Allow fprobe events to be enabled with CONFIG_DYNAMIC_FTRACE_WITH_ARGS. With this change, fprobe events mostly use ftrace_regs instead of pt_regs. Note that if the arch doesn't enable HAVE_PT_REGS_COMPAT_FTRACE_REGS, fprobe events will not be able to be used from perf. Signed-off-by: Masami Hiramatsu (Google) --- Chagnes in v3: - Use ftrace_regs_get_return_value(). Changes in v2: - Define ftrace_regs_get_kernel_stack_nth() for !CONFIG_HAVE_REGS_AND_STACK_ACCESS_API. Changes from previous series: Update against the new series. --- include/linux/ftrace.h | 17 +++++++++ kernel/trace/Kconfig | 1 - kernel/trace/trace_fprobe.c | 74 ++++++++++++++++++++---------------= ---- kernel/trace/trace_probe_tmpl.h | 2 + 4 files changed, 55 insertions(+), 39 deletions(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 8150edcf8496..ad28daa507f7 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -250,6 +250,23 @@ static __always_inline bool ftrace_regs_has_args(struc= t ftrace_regs *fregs) regs_query_register_offset(name) #endif =20 +#ifdef CONFIG_HAVE_REGS_AND_STACK_ACCESS_API +static __always_inline unsigned long +ftrace_regs_get_kernel_stack_nth(struct ftrace_regs *fregs, unsigned int n= th) +{ + unsigned long *stackp; + + stackp =3D (unsigned long *)ftrace_regs_get_stack_pointer(fregs); + if (((unsigned long)(stackp + nth) & ~(THREAD_SIZE - 1)) =3D=3D + ((unsigned long)stackp & ~(THREAD_SIZE - 1))) + return *(stackp + nth); + + return 0; +} +#else /* !CONFIG_HAVE_REGS_AND_STACK_ACCESS_API */ +#define ftrace_regs_get_kernel_stack_nth(fregs, nth) (0L) +#endif /* CONFIG_HAVE_REGS_AND_STACK_ACCESS_API */ + typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs); =20 diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 11a96275b68c..169588021d90 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -681,7 +681,6 @@ config FPROBE_EVENTS select TRACING select PROBE_EVENTS select DYNAMIC_EVENTS - depends on DYNAMIC_FTRACE_WITH_REGS default y help This allows user to add tracing events on the function entry and diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c index 22cf51217b81..d96de0dbc0cb 100644 --- a/kernel/trace/trace_fprobe.c +++ b/kernel/trace/trace_fprobe.c @@ -132,7 +132,7 @@ static int process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, void *base) { - struct pt_regs *regs =3D rec; + struct ftrace_regs *fregs =3D rec; unsigned long val; int ret; =20 @@ -140,17 +140,17 @@ process_fetch_insn(struct fetch_insn *code, void *rec= , void *dest, /* 1st stage: get value from context */ switch (code->op) { case FETCH_OP_STACK: - val =3D regs_get_kernel_stack_nth(regs, code->param); + val =3D ftrace_regs_get_kernel_stack_nth(fregs, code->param); break; case FETCH_OP_STACKP: - val =3D kernel_stack_pointer(regs); + val =3D ftrace_regs_get_stack_pointer(fregs); break; case FETCH_OP_RETVAL: - val =3D regs_return_value(regs); + val =3D ftrace_regs_get_return_value(fregs); break; #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API case FETCH_OP_ARG: - val =3D regs_get_kernel_argument(regs, code->param); + val =3D ftrace_regs_get_argument(fregs, code->param); break; #endif case FETCH_NOP_SYMBOL: /* Ignore a place holder */ @@ -170,7 +170,7 @@ NOKPROBE_SYMBOL(process_fetch_insn) /* function entry handler */ static nokprobe_inline void __fentry_trace_func(struct trace_fprobe *tf, unsigned long entry_ip, - struct pt_regs *regs, + struct ftrace_regs *fregs, struct trace_event_file *trace_file) { struct fentry_trace_entry_head *entry; @@ -184,36 +184,36 @@ __fentry_trace_func(struct trace_fprobe *tf, unsigned= long entry_ip, if (trace_trigger_soft_disabled(trace_file)) return; =20 - dsize =3D __get_data_size(&tf->tp, regs); + dsize =3D __get_data_size(&tf->tp, fregs); =20 entry =3D trace_event_buffer_reserve(&fbuffer, trace_file, sizeof(*entry) + tf->tp.size + dsize); if (!entry) return; =20 - fbuffer.regs =3D regs; + fbuffer.regs =3D ftrace_get_regs(fregs); entry =3D fbuffer.entry =3D ring_buffer_event_data(fbuffer.event); entry->ip =3D entry_ip; - store_trace_args(&entry[1], &tf->tp, regs, sizeof(*entry), dsize); + store_trace_args(&entry[1], &tf->tp, fregs, sizeof(*entry), dsize); =20 trace_event_buffer_commit(&fbuffer); } =20 static void fentry_trace_func(struct trace_fprobe *tf, unsigned long entry_ip, - struct pt_regs *regs) + struct ftrace_regs *fregs) { struct event_file_link *link; =20 trace_probe_for_each_link_rcu(link, &tf->tp) - __fentry_trace_func(tf, entry_ip, regs, link->file); + __fentry_trace_func(tf, entry_ip, fregs, link->file); } NOKPROBE_SYMBOL(fentry_trace_func); =20 /* Kretprobe handler */ static nokprobe_inline void __fexit_trace_func(struct trace_fprobe *tf, unsigned long entry_ip, - unsigned long ret_ip, struct pt_regs *regs, + unsigned long ret_ip, struct ftrace_regs *fregs, struct trace_event_file *trace_file) { struct fexit_trace_entry_head *entry; @@ -227,60 +227,63 @@ __fexit_trace_func(struct trace_fprobe *tf, unsigned = long entry_ip, if (trace_trigger_soft_disabled(trace_file)) return; =20 - dsize =3D __get_data_size(&tf->tp, regs); + dsize =3D __get_data_size(&tf->tp, fregs); =20 entry =3D trace_event_buffer_reserve(&fbuffer, trace_file, sizeof(*entry) + tf->tp.size + dsize); if (!entry) return; =20 - fbuffer.regs =3D regs; + fbuffer.regs =3D ftrace_get_regs(fregs); entry =3D fbuffer.entry =3D ring_buffer_event_data(fbuffer.event); entry->func =3D entry_ip; entry->ret_ip =3D ret_ip; - store_trace_args(&entry[1], &tf->tp, regs, sizeof(*entry), dsize); + store_trace_args(&entry[1], &tf->tp, fregs, sizeof(*entry), dsize); =20 trace_event_buffer_commit(&fbuffer); } =20 static void fexit_trace_func(struct trace_fprobe *tf, unsigned long entry_ip, - unsigned long ret_ip, struct pt_regs *regs) + unsigned long ret_ip, struct ftrace_regs *fregs) { struct event_file_link *link; =20 trace_probe_for_each_link_rcu(link, &tf->tp) - __fexit_trace_func(tf, entry_ip, ret_ip, regs, link->file); + __fexit_trace_func(tf, entry_ip, ret_ip, fregs, link->file); } NOKPROBE_SYMBOL(fexit_trace_func); =20 #ifdef CONFIG_PERF_EVENTS =20 static int fentry_perf_func(struct trace_fprobe *tf, unsigned long entry_i= p, - struct pt_regs *regs) + struct ftrace_regs *fregs) { struct trace_event_call *call =3D trace_probe_event_call(&tf->tp); struct fentry_trace_entry_head *entry; struct hlist_head *head; int size, __size, dsize; + struct pt_regs *regs; int rctx; =20 head =3D this_cpu_ptr(call->perf_events); if (hlist_empty(head)) return 0; =20 - dsize =3D __get_data_size(&tf->tp, regs); + dsize =3D __get_data_size(&tf->tp, fregs); __size =3D sizeof(*entry) + tf->tp.size + dsize; size =3D ALIGN(__size + sizeof(u32), sizeof(u64)); size -=3D sizeof(u32); =20 - entry =3D perf_trace_buf_alloc(size, NULL, &rctx); + entry =3D perf_trace_buf_alloc(size, ®s, &rctx); if (!entry) return 0; =20 + regs =3D ftrace_fill_perf_regs(fregs, regs); + entry->ip =3D entry_ip; memset(&entry[1], 0, dsize); - store_trace_args(&entry[1], &tf->tp, regs, sizeof(*entry), dsize); + store_trace_args(&entry[1], &tf->tp, fregs, sizeof(*entry), dsize); perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, head, NULL); return 0; @@ -289,30 +292,33 @@ NOKPROBE_SYMBOL(fentry_perf_func); =20 static void fexit_perf_func(struct trace_fprobe *tf, unsigned long entry_ip, - unsigned long ret_ip, struct pt_regs *regs) + unsigned long ret_ip, struct ftrace_regs *fregs) { struct trace_event_call *call =3D trace_probe_event_call(&tf->tp); struct fexit_trace_entry_head *entry; struct hlist_head *head; int size, __size, dsize; + struct pt_regs *regs; int rctx; =20 head =3D this_cpu_ptr(call->perf_events); if (hlist_empty(head)) return; =20 - dsize =3D __get_data_size(&tf->tp, regs); + dsize =3D __get_data_size(&tf->tp, fregs); __size =3D sizeof(*entry) + tf->tp.size + dsize; size =3D ALIGN(__size + sizeof(u32), sizeof(u64)); size -=3D sizeof(u32); =20 - entry =3D perf_trace_buf_alloc(size, NULL, &rctx); + entry =3D perf_trace_buf_alloc(size, ®s, &rctx); if (!entry) return; =20 + regs =3D ftrace_fill_perf_regs(fregs, regs); + entry->func =3D entry_ip; entry->ret_ip =3D ret_ip; - store_trace_args(&entry[1], &tf->tp, regs, sizeof(*entry), dsize); + store_trace_args(&entry[1], &tf->tp, fregs, sizeof(*entry), dsize); perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, head, NULL); } @@ -324,17 +330,14 @@ static int fentry_dispatcher(struct fprobe *fp, unsig= ned long entry_ip, void *entry_data) { struct trace_fprobe *tf =3D container_of(fp, struct trace_fprobe, fp); - struct pt_regs *regs =3D ftrace_get_regs(fregs); int ret =3D 0; =20 - if (!regs) - return 0; - if (trace_probe_test_flag(&tf->tp, TP_FLAG_TRACE)) - fentry_trace_func(tf, entry_ip, regs); + fentry_trace_func(tf, entry_ip, fregs); + #ifdef CONFIG_PERF_EVENTS if (trace_probe_test_flag(&tf->tp, TP_FLAG_PROFILE)) - ret =3D fentry_perf_func(tf, entry_ip, regs); + ret =3D fentry_perf_func(tf, entry_ip, fregs); #endif return ret; } @@ -345,16 +348,13 @@ static void fexit_dispatcher(struct fprobe *fp, unsig= ned long entry_ip, void *entry_data) { struct trace_fprobe *tf =3D container_of(fp, struct trace_fprobe, fp); - struct pt_regs *regs =3D ftrace_get_regs(fregs); - - if (!regs) - return; =20 if (trace_probe_test_flag(&tf->tp, TP_FLAG_TRACE)) - fexit_trace_func(tf, entry_ip, ret_ip, regs); + fexit_trace_func(tf, entry_ip, ret_ip, fregs); + #ifdef CONFIG_PERF_EVENTS if (trace_probe_test_flag(&tf->tp, TP_FLAG_PROFILE)) - fexit_perf_func(tf, entry_ip, ret_ip, regs); + fexit_perf_func(tf, entry_ip, ret_ip, fregs); #endif } NOKPROBE_SYMBOL(fexit_dispatcher); diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmp= l.h index 3935b347f874..05445a745a07 100644 --- a/kernel/trace/trace_probe_tmpl.h +++ b/kernel/trace/trace_probe_tmpl.h @@ -232,7 +232,7 @@ process_fetch_insn_bottom(struct fetch_insn *code, unsi= gned long val, =20 /* Sum up total data length for dynamic arrays (strings) */ static nokprobe_inline int -__get_data_size(struct trace_probe *tp, struct pt_regs *regs) +__get_data_size(struct trace_probe *tp, void *regs) { struct probe_arg *arg; int i, len, ret =3D 0;