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 2D39CC4332F for ; Mon, 28 Nov 2022 17:39:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233119AbiK1Ri7 (ORCPT ); Mon, 28 Nov 2022 12:38:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233118AbiK1Rii (ORCPT ); Mon, 28 Nov 2022 12:38:38 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF64927B3C; Mon, 28 Nov 2022 09:38:26 -0800 (PST) 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 ams.source.kernel.org (Postfix) with ESMTPS id A5207B80E9D; Mon, 28 Nov 2022 17:38:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 296AFC43470; Mon, 28 Nov 2022 17:38:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669657104; bh=3dvlsZ0crK7vigTaS1T23MKHxpBSClQQPfxLSsv+Jmc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TpMfIYPLurzgpEswlTow7ElAnVNxv2wYIwUzluN0OZYbpvbkVyPJrbwKNf5rejMpJ VZuk+8q9VeJyN7VZraUrd8O+WFLA1uj40m/qvxr4hbj8mHCP1ynofBCF6//Ytj2/tM 40E4MSm72UWn+GRkL5aOFxJFvE0Jp/ZG3ZYPrfqhRlegdXH1QzbGD8xvN1zaxSyffU VswD8HQBeSyiifPF+h5CnVgmeIte6GAW6uNOBrHF0f2FJcsnl5jhQqz8pfxwYtjCoC NvmYDASzruVMae7xlPwonM+0665VuFbVeS3Oe/TzwuLlUY3hRvccYTvmbBlUUoc50p SqtTm4N3v02+A== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tomislav Novak , Linus Walleij , Russell King , Sasha Levin , will@kernel.org, mark.rutland@arm.com, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, linux@armlinux.org.uk, linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org Subject: [PATCH AUTOSEL 6.0 14/39] ARM: 9251/1: perf: Fix stacktraces for tracepoint events in THUMB2 kernels Date: Mon, 28 Nov 2022 12:35:54 -0500 Message-Id: <20221128173642.1441232-14-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221128173642.1441232-1-sashal@kernel.org> References: <20221128173642.1441232-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org From: Tomislav Novak [ Upstream commit 612695bccfdbd52004551308a55bae410e7cd22f ] 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 Link: https://lore.kernel.org/r/20220920230728.2617421-1-tnovak@fb.com/ Reviewed-by: Linus Walleij Signed-off-by: Tomislav Novak Signed-off-by: Russell King (Oracle) Signed-off-by: Sasha Levin --- 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 fe87397c3d8c..bdbc1e590891 100644 --- a/arch/arm/include/asm/perf_event.h +++ b/arch/arm/include/asm/perf_event.h @@ -17,7 +17,7 @@ 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; \ } -- 2.35.1