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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1EDCC4160E for ; Wed, 3 Mar 2021 03:56:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2C9564E75 for ; Wed, 3 Mar 2021 03:56:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352552AbhCCDvT (ORCPT ); Tue, 2 Mar 2021 22:51:19 -0500 Received: from wout3-smtp.messagingengine.com ([64.147.123.19]:43003 "EHLO wout3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242893AbhCCBQq (ORCPT ); Tue, 2 Mar 2021 20:16:46 -0500 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.west.internal (Postfix) with ESMTP id A040C10F3; Tue, 2 Mar 2021 20:15:34 -0500 (EST) Received: from imap35 ([10.202.2.85]) by compute3.internal (MEProxy); Tue, 02 Mar 2021 20:15:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dxuuu.xyz; h= mime-version:message-id:date:from:to:cc:subject:content-type; s= fm2; bh=9FD8F+TWKvse0buYqi4uiNdfXk0YrVryNe2+KxwJxE4=; b=gYD8pcVL 6TcQSIXYBfnJ61EoGimU174EVWiZy1rMp4FMx/vMfSwyy090/5AdSu9hZMAp/Zop mnQJho+dwSlzjPQKxs2SkjTJDtKGE1YNo7RVb3n8QWq+Nkrb2EUk2GonUyWyZE8W fHz+mh8S+1lOkNBTvDvH0y3Tg8v3INgBcyWi/wdxS1iOYHg89zCNKIR8fsBbolC/ RhEGFTPFO8AMqSk+G5ci7TYiqfTleYAyFtkxSd4hul41vwYogt/y4dNx06crs+82 LDBPiCDoycBU2YCV+dqpI7AXUC9XjQATJMHj0kQm94R4A8OjAJzTA5lxjMMSIfa4 wSN4Yrvy/dxV+Q== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:message-id :mime-version:subject:to:x-me-proxy:x-me-proxy:x-me-sender :x-me-sender:x-sasl-enc; s=fm2; bh=9FD8F+TWKvse0buYqi4uiNdfXk0Yr VryNe2+KxwJxE4=; b=oxJR9qtnr/ARq80jMHXCFWbFYqrhra5VL5ntorj/gq22i bCY8v2ZSsNnI+dol38EmwEB6kYWPr7O+4BSuogilaXlA3YuG2xO1MKDEjfvUaTx2 cmTCzumVZLG9DnSQ107idEhhAH9zJNJiqtCBffrgAQjhN8CgtkdL3lavFMawtEz4 I9lTPMXdBBf8iiGgNri4mGUFXShs9KTqdbnp/xz2UJNOxkPui9RLcXLDk/RHKvBA oUndCxYQ2mu2d2UB07nMSWoySgolH3+YjUpBC3gT7dmA/K6c+GNKh1OYKknxFtRH ASP9lVzKccH6XNRfsAHXiHOCKX/M+Xm+HRMDdHynA== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledruddtuddgvdelucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucgfrhhlucfvnfffucdlfeehmdenucfjughrpefofg ggkfffhffvufgtsehttdertderredtnecuhfhrohhmpedfffgrnhhivghlucgiuhdfuceo ugiguhesugiguhhuuhdrgiihiieqnecuggftrfgrthhtvghrnhepgfefgedvvdeigfdthf ettdfghedtleeuteefueetiefhledvhfelleeutedufedtnecuvehluhhsthgvrhfuihii vgeptdenucfrrghrrghmpehmrghilhhfrhhomhepugiguhesugiguhhuuhdrgiihii X-ME-Proxy: Received: by mailuser.nyi.internal (Postfix, from userid 501) id C739015A005D; Tue, 2 Mar 2021 20:15:33 -0500 (EST) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.5.0-alpha0-206-g078a48fda5-fm-20210226.001-g078a48fd Mime-Version: 1.0 Message-Id: <1fed0793-391c-4c68-8d19-6dcd9017271d@www.fastmail.com> Date: Tue, 02 Mar 2021 17:15:13 -0800 From: "Daniel Xu" To: mhiramat@kernel.org Cc: linux-kernel@vger.kernel.org, "bpf@vger.kernel.org" , kuba@kernel.org Subject: Broken kretprobe stack traces Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Hi Masami, Jakub reported a bug with kretprobe stack traces -- wondering if you've gotten any bug reports related to stack traces being broken for kretprobes. I think (can't prove) this used to work: # bpftrace -e 'kretprobe:__tcp_retransmit_skb { @[kstack()] = count() }' Attaching 1 probe... ^C @[ kretprobe_trampoline+0 ]: 1 fentry/fexit probes seem to work: # bpftrace -e 'kretfunc:__tcp_retransmit_skb { @[kstack()] = count() }' Attaching 1 probe... ^C @[ ftrace_trampoline+10799 bpf_get_stackid_raw_tp+121 ftrace_trampoline+10799 __tun_chr_ioctl.isra.0.cold+33312 __tcp_retransmit_skb+5 tcp_send_loss_probe+254 tcp_write_timer_handler+394 tcp_write_timer+149 call_timer_fn+41 __run_timers+493 run_timer_softirq+25 __softirqentry_text_start+207 asm_call_sysvec_on_stack+18 do_softirq_own_stack+55 irq_exit_rcu+158 sysvec_apic_timer_interrupt+54 asm_sysvec_apic_timer_interrupt+18 ]: 1 @[ ftrace_trampoline+10799 bpf_get_stackid_raw_tp+121 ftrace_trampoline+10799 __tun_chr_ioctl.isra.0.cold+33312 __tcp_retransmit_skb+5 <...> which makes me suspect it's a kprobe specific issue. Thanks, Daniel