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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 3EE45C433DF for ; Thu, 9 Jul 2020 02:22:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 19B7920772 for ; Thu, 9 Jul 2020 02:22:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594261340; bh=IjdtSlJXRmG6r+nd+2Dh8aAjMl93vMm0DifIAImCrMM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=yDutavkRjcnxFYIdOx+E1pn0kw5zeka3PxFVUs2C6HtyFxL/3s2zl8iSZVRvuNjIz I4b6z5pjTeJHPupkKAKqOkYsRrh6HuRV5aCXJV7ICzILjVG0+r0rraFk6ETvvJmvvE kyIEWPj1sltqioAOuMs7+S9k8fwfUqGrZuuVTXRg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726151AbgGICWO (ORCPT ); Wed, 8 Jul 2020 22:22:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:37618 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726082AbgGICWO (ORCPT ); Wed, 8 Jul 2020 22:22:14 -0400 Received: from localhost.localdomain (unknown [42.120.72.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 407A0206F6; Thu, 9 Jul 2020 02:22:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594261333; bh=IjdtSlJXRmG6r+nd+2Dh8aAjMl93vMm0DifIAImCrMM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zur6KN/NoD/YfRFtXQdAXninSb8vMUy5xTzvky1bdLa7/5GSWlLIKib6uyw6lTqNi qKibIDAjkXFWl5PA3UB+ptR1Z3P8lubuDW1RidMpBi8J13Ay2xc24ggypgihLDDp5P MwvLkLGnemHSPXdK3kTowUyVmU4nuDUtmJV4NHjM= From: guoren@kernel.org To: palmerdabbelt@google.com, paul.walmsley@sifive.com, anup@brainfault.org, greentime.hu@sifive.com, zong.li@sifive.com, me@packi.ch, bjorn.topel@gmail.com, atish.patra@wdc.com, penberg@kernel.org, mhiramat@kernel.org Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, guoren@kernel.org, Guo Ren , Vincent Chen , Alan Kao , Greentime Hu Subject: [PATCH v2 1/6] riscv: Fixup __vdso_gettimeofday broke dynamic ftrace Date: Thu, 9 Jul 2020 02:19:09 +0000 Message-Id: <1594261154-69745-2-git-send-email-guoren@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1594261154-69745-1-git-send-email-guoren@kernel.org> References: <1594261154-69745-1-git-send-email-guoren@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Guo Ren For linux-5.8-rc1, enable ftrace of riscv will cause boot panic: [ 2.388980] Run /sbin/init as init process [ 2.529938] init[39]: unhandled signal 4 code 0x1 at 0x0000003ff449e000 [ 2.531078] CPU: 0 PID: 39 Comm: init Not tainted 5.8.0-rc1-dirty #13 [ 2.532719] epc: 0000003ff449e000 ra : 0000003ff449e954 sp : 0000003fffedb900 [ 2.534005] gp : 00000000000e8528 tp : 0000003ff449d800 t0 : 000000000000001e [ 2.534965] t1 : 000000000000000a t2 : 0000003fffedb89e s0 : 0000003fffedb920 [ 2.536279] s1 : 0000003fffedb940 a0 : 0000003ff43d4b2c a1 : 0000000000000000 [ 2.537334] a2 : 0000000000000001 a3 : 0000000000000000 a4 : fffffffffbad8000 [ 2.538466] a5 : 0000003ff449e93a a6 : 0000000000000000 a7 : 0000000000000000 [ 2.539511] s2 : 0000000000000000 s3 : 0000003ff448412c s4 : 0000000000000010 [ 2.541260] s5 : 0000000000000016 s6 : 00000000000d0a30 s7 : 0000003fffedba70 [ 2.542152] s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000003fffedb960 [ 2.543335] s11: 0000000000000000 t3 : 0000000000000000 t4 : 0000003fffedb8a0 [ 2.544471] t5 : 0000000000000000 t6 : 0000000000000000 [ 2.545730] status: 0000000000004020 badaddr: 00000000464c457f cause: 0000000000000002 [ 2.549867] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004 [ 2.551267] CPU: 0 PID: 1 Comm: init Not tainted 5.8.0-rc1-dirty #13 [ 2.552061] Call Trace: [ 2.552626] [] walk_stackframe+0x0/0xc4 [ 2.553486] [] show_stack+0x40/0x4c [ 2.553995] [] dump_stack+0x7a/0x98 [ 2.554615] [] panic+0x114/0x2f4 [ 2.555395] [] do_exit+0x89c/0x8c2 [ 2.555949] [] do_group_exit+0x3a/0x90 [ 2.556715] [] get_signal+0xe2/0x6e6 [ 2.557388] [] do_notify_resume+0x6a/0x37a [ 2.558089] [] ret_from_exception+0x0/0xc "ra:0x3ff449e954" is the return address of "call _mcount" in the prologue of __vdso_gettimeofday(). Without proper relocate, pc jmp to 0x0000003ff449e000 (vdso map base) with a illegal instruction trap. The solution comes from arch/arm64/kernel/vdso/Makefile: CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) - CC_FLAGS_SCS is ShadowCallStack feature in Clang and only implemented for arm64, no use for riscv. The bug comes from the following commit: ad5d1122b82f ("riscv: use vDSO common flow to reduce the latency of the time-related functions") Signed-off-by: Guo Ren Reviewed-by: Pekka Enberg Cc: Vincent Chen Cc: Atish Patra Cc: Palmer Dabbelt Cc: Alan Kao Cc: Greentime Hu --- arch/riscv/kernel/vdso/Makefile | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile index 38ba55b..3079935 100644 --- a/arch/riscv/kernel/vdso/Makefile +++ b/arch/riscv/kernel/vdso/Makefile @@ -27,6 +27,9 @@ obj-vdso := $(addprefix $(obj)/, $(obj-vdso)) obj-y += vdso.o vdso-syms.o CPPFLAGS_vdso.lds += -P -C -U$(ARCH) +# Disable -pg to prevent insert call site +CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os + # Disable gcov profiling for VDSO code GCOV_PROFILE := n -- 2.7.4