From patchwork Mon May 1 15:09:56 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 89069 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:c790:0:b0:3b6:ef29:a0d7 with SMTP id b16csp63105vqu; Mon, 1 May 2023 08:19:48 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ70Sss1e/AkZkVHHRHr2I5HNgB3Qz2k6Db3YKJV+ZJeIGLxTIN97Xc5O3kK7/qYiHJgSBFM X-Received: by 2002:a17:90a:850a:b0:24e:1f8:b786 with SMTP id l10-20020a17090a850a00b0024e01f8b786mr3542730pjn.19.1682954387796; Mon, 01 May 2023 08:19:47 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1682954387; cv=none; d=google.com; s=arc-20160816; b=YgIGK9Lu4PLCe5ZpjywOj+IhHw0xX9TOJ+GRJ3FdBXOBA3Lp568uM6i2TYxUMsEert WTV19MR4ohxUnWOq21fkQ315sDgke574GRYkBto+gmh/3LJy+9sk9ZoJBMx8AgWYw/FV 2c2dmq/1vbpP0aScRYgVFj9aToxisOUWVvv1Jnu24if8Vv2SaGNjSOFJYReCWROatMxy 6Ba2720Yrt49JvpA+ABxPWWgy9ZzbYNVwjTVH1FVojgy+h8tfGD+cx/7Z6wnxuWlgsWR hzPe08cWGAO3Y1GG2QOAAXJlLOlEL9UqPGY2MT1RswgWuPwwBc4iyNr/FaDBpIkPBkre t9RQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=n1/GHAN78BJCDW6f2uDWjGj4U0t/2BqDON+dtufTVpY=; b=mTZl6a0lUZhbi167Zz2DIadJSnTWXeAawXskrXrxSwdRaHl1TVxoQsyijygKciBBsx XZNpI/qap3Hj18X5eugOt6StnWGElVB2dicY/1jttK6VvubMmCfFRCGxHWC7QJzTQ8CT pMUyAs/+/YJ0Hv5FeoZmEL6C2Jyi646iApBQNZBNpTbTJI5jYKQQhI1r6y8BOtYSxIbr xKYnzDGBcjLeO7QGFyOX4h9ihcsRDkQ/53im4gKGlN8EwyDJOyeF+TFdgOJ7fTz89mN/ xNu9sV0eZWPvXBg1LjLr3w/OX1aVJkRPkUE8ScwD577fXU73pKkyLcmwUSJiDUlrmUSn aFIw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=t0Dfv8BX; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id mi5-20020a17090b4b4500b002468b3ff982si9803880pjb.121.2023.05.01.08.19.35; Mon, 01 May 2023 08:19:47 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=t0Dfv8BX; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232792AbjEAPKs (ORCPT + 99 others); Mon, 1 May 2023 11:10:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41400 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232761AbjEAPKj (ORCPT ); Mon, 1 May 2023 11:10:39 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 131811BC3; Mon, 1 May 2023 08:10:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9FCCF61D9E; Mon, 1 May 2023 15:10:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75C07C433D2; Mon, 1 May 2023 15:09:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1682953800; bh=Icqeq3QwnfHGN8wBY8+CK+wy8jM0tZWZCoVTU5qCdms=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=t0Dfv8BXBp1IFRFZt7sGdhqjTVgbXghNyhIZRGUiU1Opo/KGVVpZO1/06Okt8YYNp kgrjVL/Bfl2z6BJG/r5+354x1oAPAyS7erm+118B36Ph3XmOmlJ2mUUGhAnU2Jh/2R H9ZHEkSFxjWtfrcDd+fwJQGeEM++YouRK1QmgMbFc/Q1WyorWzDHtypJKryvjJksHj vszbEfDlVO/TFdBc3zIGfMcQBg5aCigO82zKemG0HIexd8V+JYr23rWa5RVR42I5nt Vp4KmpzKxakiyxglfodY8+Tj3I5aEWu8CLg6r6a8IaN1G/W1aqtetYTL8nz/3kigdm Bdj5yqD5FYyQw== From: "Masami Hiramatsu (Google)" To: linux-trace-kernel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Steven Rostedt , mhiramat@kernel.org, Florent Revest , Mark Rutland , Will Deacon , Mathieu Desnoyers , Martin KaFai Lau , bpf@vger.kernel.org Subject: [PATCH v9 08/11] tracing/probes: Add BTF retval type support Date: Tue, 2 May 2023 00:09:56 +0900 Message-ID: <168295379661.3157983.2481953230424989387.stgit@mhiramat.roam.corp.google.com> X-Mailer: git-send-email 2.40.1.495.gc816e09b53d-goog In-Reply-To: <168295372484.3157983.731333785390494141.stgit@mhiramat.roam.corp.google.com> References: <168295372484.3157983.731333785390494141.stgit@mhiramat.roam.corp.google.com> User-Agent: StGit/0.19 MIME-Version: 1.0 X-Spam-Status: No, score=-4.6 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1764705579969303503?= X-GMAIL-MSGID: =?utf-8?q?1764705579969303503?= From: Masami Hiramatsu (Google) Check the target function has non-void retval type and set the correct fetch type if user doesn't specify it. If the function returns void, $retval is rejected as below; # echo 'f unregister_kprobes%return $retval' >> dynamic_events sh: write error: No such file or directory # cat error_log [ 37.488397] trace_fprobe: error: This function returns 'void' type Command: f unregister_kprobes%return $retval ^ Signed-off-by: Masami Hiramatsu (Google) --- Changes in v8: - Fix wrong indentation. Changes in v7: - Introduce this as a new patch. --- kernel/trace/trace_probe.c | 67 ++++++++++++++++++++++++++++++++++++++++---- kernel/trace/trace_probe.h | 1 + 2 files changed, 62 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 4c3c70862a9a..cf1f05c230e8 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -371,13 +371,13 @@ static const char *type_from_btf_id(struct btf *btf, s32 id) return NULL; } -static const struct btf_param *find_btf_func_param(const char *funcname, s32 *nr) +static const struct btf_type *find_btf_func_proto(const char *funcname) { struct btf *btf = traceprobe_get_btf(); const struct btf_type *t; s32 id; - if (!btf || !funcname || !nr) + if (!btf || !funcname) return ERR_PTR(-EINVAL); id = btf_find_by_name_kind(btf, funcname, BTF_KIND_FUNC); @@ -394,6 +394,20 @@ static const struct btf_param *find_btf_func_param(const char *funcname, s32 *nr if (!btf_type_is_func_proto(t)) return ERR_PTR(-ENOENT); + return t; +} + +static const struct btf_param *find_btf_func_param(const char *funcname, s32 *nr) +{ + const struct btf_type *t; + + if (!funcname || !nr) + return ERR_PTR(-EINVAL); + + t = find_btf_func_proto(funcname); + if (IS_ERR(t)) + return (const struct btf_param *)t; + *nr = btf_type_vlen(t); if (*nr) @@ -452,6 +466,32 @@ static const struct fetch_type *parse_btf_arg_type(int arg_idx, return find_fetch_type(typestr, ctx->flags); } +static const struct fetch_type *parse_btf_retval_type( + struct traceprobe_parse_context *ctx) +{ + struct btf *btf = traceprobe_get_btf(); + const char *typestr = NULL; + const struct btf_type *t; + + if (btf && ctx->funcname) { + t = find_btf_func_proto(ctx->funcname); + if (!IS_ERR(t)) + typestr = type_from_btf_id(btf, t->type); + } + + return find_fetch_type(typestr, ctx->flags); +} + +static bool is_btf_retval_void(const char *funcname) +{ + const struct btf_type *t; + + t = find_btf_func_proto(funcname); + if (IS_ERR(t)) + return false; + + return t->type == 0; +} #else static struct btf *traceprobe_get_btf(void) { @@ -469,8 +509,15 @@ static int parse_btf_arg(const char *varname, struct fetch_insn *code, trace_probe_log_err(ctx->offset, NOSUP_BTFARG); return -EOPNOTSUPP; } + #define parse_btf_arg_type(idx, ctx) \ find_fetch_type(NULL, ctx->flags) + +#define parse_btf_retval_type(ctx) \ + find_fetch_type(NULL, ctx->flags) + +#define is_btf_retval_void(funcname) (false) + #endif #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) @@ -500,7 +547,12 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, if (strcmp(arg, "retval") == 0) { if (ctx->flags & TPARG_FL_RETURN) { - code->op = FETCH_OP_RETVAL; + if ((ctx->flags & TPARG_FL_KERNEL) && + is_btf_retval_void(ctx->funcname)) { + trace_probe_log_err(ctx->offset, NO_RETVAL); + ret = -ENOENT; + } else + code->op = FETCH_OP_RETVAL; } else { trace_probe_log_err(ctx->offset, RETVAL_ON_PROBE); ret = -EINVAL; @@ -887,9 +939,12 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, goto fail; /* Update storing type if BTF is available */ - if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && - !t && code->op == FETCH_OP_ARG) - parg->type = parse_btf_arg_type(code->param, ctx); + if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && !t) { + if (code->op == FETCH_OP_ARG) + parg->type = parse_btf_arg_type(code->param, ctx); + else if (code->op == FETCH_OP_RETVAL) + parg->type = parse_btf_retval_type(ctx); + } ret = -EINVAL; /* Store operation */ diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 8c5b029c5d62..3eb7c37c0984 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -444,6 +444,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, C(BAD_EVENT_NAME, "Event name must follow the same rules as C identifiers"), \ C(EVENT_EXIST, "Given group/event name is already used by another event"), \ C(RETVAL_ON_PROBE, "$retval is not available on probe"), \ + C(NO_RETVAL, "This function returns 'void' type"), \ C(BAD_STACK_NUM, "Invalid stack number"), \ C(BAD_ARG_NUM, "Invalid argument number"), \ C(BAD_VAR, "Invalid $-valiable specified"), \