From mboxrd@z Thu Jan 1 00:00:00 1970 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 00224C433FE for ; Wed, 23 Nov 2022 14:21:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238005AbiKWOVY (ORCPT ); Wed, 23 Nov 2022 09:21:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238158AbiKWOUv (ORCPT ); Wed, 23 Nov 2022 09:20:51 -0500 Received: from mail-pg1-x52b.google.com (mail-pg1-x52b.google.com [IPv6:2607:f8b0:4864:20::52b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82F1563B94 for ; Wed, 23 Nov 2022 06:20:36 -0800 (PST) Received: by mail-pg1-x52b.google.com with SMTP id n17so16865654pgh.9 for ; Wed, 23 Nov 2022 06:20:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=XZFGbUHuj0l3eTvqxn5eZPM/wQWRlW8EgGqFLB4IDbY=; b=UL7NA71lQETMtiGLB4b0vM0bIK56V9BIy15nU3u5/XO87jW95LGcNVZRn2UtQZSPSc ib4fv/ro/oGNdRLn3kROOEzKedIeVrJ4sGqAxbtte0g5oGuRMTQhCm+Y4+hsD2aj6xks sFacIImq75unL4GkwndLhKm9NL5akxb8zUaN6I3uzG5cs15I5ajNYz/dy/3EM/H8x471 o0sHHUmnjy2wQM5//on9q7SoZTzB+kxQ4gJQFRrzGAgblMp65KmmYEc69lS6gW9U12lG YZsJckaaoZmVJt295ri6d6ODV4/X6jgu8PGhbLxZFHKhO+6J8sgD7klB1qqFZyO++fnu oPEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=XZFGbUHuj0l3eTvqxn5eZPM/wQWRlW8EgGqFLB4IDbY=; b=L/fB6TWmtr38g8T1RblgUly68O0b3mMcgkoK8SjSH2rInl77Ce+7mAwFrgyrwlFV3q suV3tCXw7IqZI0pJ4tQVWFvIcvJL7SrIb16F6RgWZXk3xnkuQhd4A6Husy0uxZNkUsjZ NyGxikZyYKKwpcmCeS8LlOT9xSV/K+PP290RaoIwdAmcwijOwg2ucTPCsQZUjy12D15W tsvh0twuGLnZD2af0tCUR4Oy3TO5/+W+e/PaGPngvdHYOdKiJ0rkxN3hKTpJcoQAl156 StnW+9eytxLMGdeLPB6opNxUIBSA7Z+iMy1Iq57Wa3a6E0HciHewjDH29wxRAoIyV8Mg MUOg== X-Gm-Message-State: ANoB5pnUt5pwQo32BaqFpJmoAG5MDNr3bFzZWD7CsuZpn+0WNO9TDBh+ XSoUKkSEm/fyrcQ0ZCTofok= X-Google-Smtp-Source: AA0mqf4hksRNl+NtDdclonmxEt2Mu9yopFQcQjze1yeU9La5Gipr9oXvhlZA7HVc1KIQasBaNuiYtg== X-Received: by 2002:a63:711e:0:b0:477:5654:c37e with SMTP id m30-20020a63711e000000b004775654c37emr16425758pgc.206.1669213234292; Wed, 23 Nov 2022 06:20:34 -0800 (PST) Received: from localhost.localdomain ([221.226.144.218]) by smtp.gmail.com with ESMTPSA id l12-20020a170903120c00b0016c5306917fsm14516732plh.53.2022.11.23.06.20.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Nov 2022 06:20:33 -0800 (PST) From: Song Shuai To: guoren@kernel.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, rostedt@goodmis.org, mhiramat@kernel.org, mark.rutland@arm.com, peterz@infradead.org, jolsa@redhat.com, bp@suse.de, jpoimboe@kernel.org Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Song Shuai Subject: [PATCH 0/2] riscv/ftrace: add WITH_DIRECT_CALLS support Date: Wed, 23 Nov 2022 22:20:23 +0800 Message-Id: <20221123142025.1504030-1-suagrfillet@gmail.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS support for RISC-V. SAMPLE_FTRACE_DIRECT and SAMPLE_FTRACE_DIRECT_MULTI are also included here as the samples for testing DIRECT_CALLS related interface. First, select the DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide register_ftrace_direct[_multi] interfaces allowing user to register the customed trampoline (direct_caller) as the mcount for one or more target functions. And modify_ftrace_direct[_multi] are also provided for modify direct_caller. At the same time, the samples in ./samples/ftrace/ can be built as kerenl module for testing these interfaces with SAMPLE_FTRACE_DIRECT and SAMPLE_FTRACE_DIRECT_MULTI selected. Second, to make the direct_caller and the other ftrace hooks (eg. function/fgraph tracer, k[ret]probes) co-exist, a temporary register are nominated to store the address of direct_caller in ftrace_regs_caller. After the setting of the address direct_caller by direct_ops->func and the RESTORE_REGS in ftrace_regs_caller, direct_caller will be jumped to by the `jr` inst. The following tests have been passed in my local qemu-riscv64 virt machine. 1. tests with CONFIG_FTRACE_STARTUP_TEST 2. tests of samples/ftrace/ftrace*.ko 3. manual tests with any combination of the following hooks - function/function_graph tracer - ftrace*.ko - kprobe/kretprobe For your reference, here is the log when function tracer, kretprobe and ftrace-direct-too.ko co-hooks the handle_mm_fault function. ``` [root@stage4 tracing]# echo handle_mm_fault > set_ftrace_filter [root@stage4 tracing]# echo 'r:myr handle_mm_fault' > kprobe_events [root@stage4 tracing]# echo function > current_tracer [root@stage4 tracing]# echo 1 > events/kprobes/myr/enable [root@stage4 tracing]# insmod /root/ftrace-direct-too.ko [root@stage4 tracing]# [root@stage4 tracing]# cat trace | tail cat-388 [000] ...1. 583.051438: myr: (do_page_fault+0x16c/0x5f2 <- handle_mm_fault) cat-388 [000] ...2. 583.057930: handle_mm_fault <-do_page_fault cat-388 [000] ..... 583.057990: my_direct_func: handle mm fault vma=000000002d9fe19c address=ffffffae9b7000 flags=215 cat-388 [000] ...1. 583.058284: myr: (do_page_fault+0x16c/0x5f2 <- handle_mm_fault) tail-389 [001] ...2. 583.059062: handle_mm_fault <-do_page_fault tail-389 [001] ..... 583.059104: my_direct_func: handle mm fault vma=0000000017f3c48e address=aaaaaabebf3000 flags=215 tail-389 [001] ...1. 583.059325: myr: (do_page_fault+0x16c/0x5f2 <- handle_mm_fault) tail-389 [001] ...2. 583.060371: handle_mm_fault <-do_page_fault tail-389 [001] ..... 583.060410: my_direct_func: handle mm fault vma=0000000017f3c48e address=aaaaaabebf1000 flags=255 tail-389 [001] ...1. 583.060996: myr: (do_page_fault+0x16c/0x5f2 <- handle_mm_fault) ``` Note1: This series is based on (riscv/ftrace: make ftrace_caller call ftrace_graph_func) in this repo -> https://github.com/guoren83/linux/commits/ftrace_fixup_v3 . Note2: The checkpatch.pl will output some warnings on this series, like this ``` WARNING: Prefer using '"%s...", __func__' to using 'my_direct_func2', this function's name, in a string 111: FILE: samples/ftrace/ftrace-direct-multi-modify.c:48: +" call my_direct_func2\n" ``` The reason is that checkpatch depends on patch context providing the function name. In the above warning, my_direct_func2 has some codeline distance with the changed trunk, so its declaration doesn't come into the patch, and then the warning jumps out. You may notice the location of `my_ip` variable changes in the 2nd patch. I did that for reducing the warnings to some extent. But killing all the warnings will makes the patch less readable, so I stopped here. -- Song Song Shuai (2): riscv/ftrace: add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support samples/ftrace: add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI] arch/riscv/Kconfig | 3 ++ arch/riscv/include/asm/ftrace.h | 6 ++++ arch/riscv/kernel/mcount-dyn.S | 4 +++ samples/ftrace/ftrace-direct-modify.c | 35 ++++++++++++++++++- samples/ftrace/ftrace-direct-multi-modify.c | 37 +++++++++++++++++++++ samples/ftrace/ftrace-direct-multi.c | 22 ++++++++++++ samples/ftrace/ftrace-direct-too.c | 26 +++++++++++++++ samples/ftrace/ftrace-direct.c | 22 ++++++++++++ 8 files changed, 154 insertions(+), 1 deletion(-) -- 2.20.1