From patchwork Sat Jan 7 13:35:43 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guo Ren X-Patchwork-Id: 40398 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:4e01:0:0:0:0:0 with SMTP id p1csp1302791wrt; Sat, 7 Jan 2023 05:37:08 -0800 (PST) X-Google-Smtp-Source: AMrXdXtNT72YZaUe3Z0uEUmIC5xcN4V4raaoAdCDSpIVptYLdxZz2lwAIs7mUiSKGUqqvsclX6cQ X-Received: by 2002:a17:907:a48b:b0:84d:12db:fd22 with SMTP id vp11-20020a170907a48b00b0084d12dbfd22mr8901673ejc.71.1673098628189; Sat, 07 Jan 2023 05:37:08 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1673098628; cv=none; d=google.com; s=arc-20160816; b=ILYPrRxStp8nKcG+ACJAi6+qWiwrt8HS3fvT24iZUinUPoWzXNKUsiCDj5eG4vfERH Z1hVbmBXoSQWzsKdB8hzrjsQZ4UyW5dp6xQXRT+3mK8hYZFqxrNA0rBfozAjwUWoMkRQ 34O/flzXaBEVKKWmEmBgMnZU2LArf2z/d8hfgsRB1hDUopL5fvDzfsxu84/8eGUsDauH k03lEhZESaLD0G5FHfozfzWTgA6kK9HY2pjkapAbxPf48nF1MRJjtcTPuf8qISBZ0EsW aZFcJuyx2KTZCSnf+RAgBDk4791N5jkemG9ev8NYaMItcV+v1gNTmjk1GNnqcU54h5gk kzKQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=mDu3Gx69bunIYUgXh5x6UnX1IK7458HyOIzUj6TlLqo=; b=APEusXPTZAG09oSsNZ+sf77Bnu5ToOVkp/0TFFTdVxrAW6AD/tENq3G4W1ERg3cCiC si5uEKQGTgygOMzxUAoCyym/ITlC1Pumnw1n5g2npOSXGksP6lhNtWScvCY3CvtAvEkG 417SG2XfnJNpcZozGURx2FOh4+c1Hs2m5/0H+si2rBoVgH6uXXEs4O1krACzKj5F9nHa nCUUo0NpT6f+vsWn8FS5PU8j95MU2c2YdHGHby0kKtBkdqA+jrTH6xCcvbbSToCwFYzh B1JyYnP0d18KgFW7HjOIPOYoj6ZkNHWM/2+TScGa4MYgGUnKpyTYREyPcyvY0XhNEuF2 QxGw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b="s7tw01/F"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id du16-20020a17090772d000b007aee7ca1184si3920931ejc.602.2023.01.07.05.36.45; Sat, 07 Jan 2023 05:37:08 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b="s7tw01/F"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232272AbjAGNgQ (ORCPT + 99 others); Sat, 7 Jan 2023 08:36:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230350AbjAGNgL (ORCPT ); Sat, 7 Jan 2023 08:36:11 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0EDA7115D for ; Sat, 7 Jan 2023 05:36:11 -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 AA480B80EBF for ; Sat, 7 Jan 2023 13:36:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6882AC433F1; Sat, 7 Jan 2023 13:36:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673098568; bh=V792wXFwxvPtjCh6mve4UN0IqpgiVRIo4oWLOTpVhcc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=s7tw01/FJa7C+JS9FZn2vOZ1EHRhzYsw4UqVMHAqi+KSlSeQe11jXV0Z0nBNBHqUq lgt/sMmwoJSGgpgzejN67lpJZYcSogDUvOGDUXWwVIT4DgT/cRD16fPc9UTPCmi+M3 LXQc5TwDcZqfJmuhyWwCYXbCbdaXZRZtxGZrDaotUQjfmSzMfrtgKyLnx/c0z1QlvW SlCvNWugTwm827ZEnjOS9zXnUeUmAPZmAG4/tr6Ra6Ne1jM2RMlo9eDIxJn/XVp+jW IM5OA0GxZjo74KJ36V6CHx9C+G9PFmAUJPuZ7ZDQb39yb+hZ4RBUViYyGBNvu7V6nl 0CjAy+71op0kA== From: guoren@kernel.org To: anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, conor.dooley@microchip.com, heiko@sntech.de, rostedt@goodmis.org, mhiramat@kernel.org, jolsa@redhat.com, bp@suse.de, jpoimboe@kernel.org, suagrfillet@gmail.com, andy.chiu@sifive.com, e.shatokhin@yadro.com, guoren@kernel.org Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH -next V6 1/7] riscv: ftrace: Fixup panic by disabling preemption Date: Sat, 7 Jan 2023 08:35:43 -0500 Message-Id: <20230107133549.4192639-2-guoren@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20230107133549.4192639-1-guoren@kernel.org> References: <20230107133549.4192639-1-guoren@kernel.org> MIME-Version: 1.0 X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1754371067062689927?= X-GMAIL-MSGID: =?utf-8?q?1754371067062689927?= From: Andy Chiu In RISCV, we must use an AUIPC + JALR pair to encode an immediate, forming a jump that jumps to an address over 4K. This may cause errors if we want to enable kernel preemption and remove dependency from patching code with stop_machine(). For example, if a task was switched out on auipc. And, if we changed the ftrace function before it was switched back, then it would jump to an address that has updated 11:0 bits mixing with previous XLEN:12 part. p: patched area performed by dynamic ftrace ftrace_prologue: p| REG_S ra, -SZREG(sp) p| auipc ra, 0x? ------------> preempted ... change ftrace function ... p| jalr -?(ra) <------------- switched back p| REG_L ra, -SZREG(sp) func: xxx ret Fixes: afc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT") Signed-off-by: Andy Chiu Signed-off-by: Guo Ren --- arch/riscv/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index e2b656043abf..ee0d39b26794 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -138,7 +138,7 @@ config RISCV select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL select HAVE_FUNCTION_GRAPH_TRACER - select HAVE_FUNCTION_TRACER if !XIP_KERNEL + select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION config ARCH_MMAP_RND_BITS_MIN default 18 if 64BIT