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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3A558C6FA82 for ; Tue, 20 Sep 2022 23:19:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=P3Kod3ZW3iAaRVSbhyGsEvI5J4MX8hmgc8l0G8cZ7uQ=; b=KW04yHk5lAG//f Yq1YdJakpvv549RBsAVVZ96AXTkCq5iTdDIK3mVPoidea6He0QmqsTqoeahPCyKlZWZwA+0shzVlR FUQ5xg97ibFrx9DYsk0C49znsAfdTuBhEotzemgApjwZj0rvkYSROj6ilrCQE7B92l5ZVHyWnKvY4 nBdrsSEUWB5UXOJb8pjfpKr+7451twtGU5T3792TX9xzcD0Pd6yN2pTHHu5b8jLLhFfqjqojIITZy i3UrcsqUYXChyXfTlN4SdHYd+0WOXq1H76xS/8Irthf2Nnv7HlJClf7CFF8d8FkMTwTvZgAYmQVZ4 /rzpVn/cb29LbZWT7nIg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oamVp-007Wi8-BY; Tue, 20 Sep 2022 23:18:45 +0000 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oamVm-007WgF-FE for linux-arm-kernel@lists.infradead.org; Tue, 20 Sep 2022 23:18:43 +0000 Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 28KL3OP7005169 for ; Tue, 20 Sep 2022 16:18:38 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=facebook; bh=/FsXz362tTXUV5RNt+YyAaqLzyjQdWs0TQ3xXJfn6Is=; b=Dq0CwWBkGavz4zmoswQnrsmFU5IGtfGn+zoMZ6ZIUG8zkuNyV+tNFRIVl5VRObT0WVEC n2dLPFNQPBoI7sRteCytQ0YTm9dgSGM4ywYzubJlScsRaxn6RurqTsfTpxkNMPF+V3aA j+fGhynrRJgJUqFf/oPxFNk0esnJ1oLEQDI= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3jq8jv6mp0-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 20 Sep 2022 16:18:38 -0700 Received: from twshared20183.05.prn5.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:11d::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 20 Sep 2022 16:18:37 -0700 Received: by devvm8797.prn0.facebook.com (Postfix, from userid 2982) id 53885AFB5A16; Tue, 20 Sep 2022 16:08:01 -0700 (PDT) From: Tomislav Novak To: Will Deacon CC: Russell King , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , , , , Tomislav Novak Subject: [PATCH] ARM: perf: Fix stacktraces for tracepoint events in THUMB2 kernels Date: Tue, 20 Sep 2022 16:07:28 -0700 Message-ID: <20220920230728.2617421-1-tnovak@fb.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: NtCVZSXCHhb_gdr0KRGwLbnu3mwgQDyE X-Proofpoint-GUID: NtCVZSXCHhb_gdr0KRGwLbnu3mwgQDyE X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1 definitions=2022-09-20_11,2022-09-20_02,2022-06-22_01 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220920_161842_637500_CA9CDC60 X-CRM114-Status: GOOD ( 18.53 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Store the frame address where arm_get_current_stackframe() looks for it (ARM_r7 instead of ARM_fp if CONFIG_THUMB2_KERNEL=y). Otherwise frame->fp gets set to 0, causing unwind_frame() to fail. # bpftrace -e 't:sched:sched_switch { @[kstack] = count(); exit(); }' Attaching 1 probe... @[ __schedule+1059 ]: 1 A typical first unwind instruction is 0x97 (SP = R7), so after executing it SP ends up being 0 and -URC_FAILURE is returned. unwind_frame(pc = ac9da7d7 lr = 00000000 sp = c69bdda0 fp = 00000000) unwind_find_idx(ac9da7d7) unwind_exec_insn: insn = 00000097 unwind_exec_insn: fp = 00000000 sp = 00000000 lr = 00000000 pc = 00000000 With this patch: # bpftrace -e 't:sched:sched_switch { @[kstack] = count(); exit(); }' Attaching 1 probe... @[ __schedule+1059 __schedule+1059 schedule+79 schedule_hrtimeout_range_clock+163 schedule_hrtimeout_range+17 ep_poll+471 SyS_epoll_wait+111 sys_epoll_pwait+231 __ret_fast_syscall+1 ]: 1 Signed-off-by: Tomislav Novak --- arch/arm/include/asm/perf_event.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/include/asm/perf_event.h b/arch/arm/include/asm/perf_event.h index 4f9dec489931..c5d27140834e 100644 --- a/arch/arm/include/asm/perf_event.h +++ b/arch/arm/include/asm/perf_event.h @@ -21,7 +21,7 @@ extern unsigned long perf_misc_flags(struct pt_regs *regs); #define perf_arch_fetch_caller_regs(regs, __ip) { \ (regs)->ARM_pc = (__ip); \ - (regs)->ARM_fp = (unsigned long) __builtin_frame_address(0); \ + frame_pointer((regs)) = (unsigned long) __builtin_frame_address(0); \ (regs)->ARM_sp = current_stack_pointer; \ (regs)->ARM_cpsr = SVC_MODE; \ } -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel