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 3FA52C433FE for ; Mon, 28 Nov 2022 17:49:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233849AbiK1Rtr (ORCPT ); Mon, 28 Nov 2022 12:49:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233684AbiK1RsK (ORCPT ); Mon, 28 Nov 2022 12:48:10 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8DF172AC6D; Mon, 28 Nov 2022 09:43:10 -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 dfw.source.kernel.org (Postfix) with ESMTPS id B2F64612E4; Mon, 28 Nov 2022 17:43:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C7AAAC43470; Mon, 28 Nov 2022 17:43:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669657389; bh=+5GGC/8eufWXSVnOGBvw3X8yB+l1PO1V+/FGgW8gFtc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Gyv/UkFEQS/ef6VPs9qePlP0i6He1fbOZpmH42lzfaI2NsMg6a1xJzISuJGvUutEQ giFbr36TantQaNkf+gtcQI/34Ny8pohP5CU4Wi46ifWkG+vUr3T3dhJzLZoCsSB+7e iAKbS5ROJcz/YNa1RS+zG73vo0FseQv0BhjZ729ot4/qsvig+gAowogrISv1wQWOpI 0AAiQkJfVfhHcE5v7iwCtNnJVkDqemgKAPTpcWExZH36mltG/LtIlNhch2QGjU+i0Z woI2bE2d1oMLJjZIxTiZ1FRAOFKGM1XByctiLX51HXENhhPNK6sw/slkWUG3iPs/tI iTH17vpbm3eMw== 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 4.14 3/9] ARM: 9251/1: perf: Fix stacktraces for tracepoint events in THUMB2 kernels Date: Mon, 28 Nov 2022 12:42:56 -0500 Message-Id: <20221128174303.1443008-3-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221128174303.1443008-1-sashal@kernel.org> References: <20221128174303.1443008-1-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 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; \ } -- 2.35.1