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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C6D6C43217 for ; Tue, 9 Nov 2021 22:22:50 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 691E361506 for ; Tue, 9 Nov 2021 22:22:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 691E361506 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4HpjCr0bGGz3dbH for ; Wed, 10 Nov 2021 09:22:48 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=ZhXr5rLl; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=sashal@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=ZhXr5rLl; dkim-atps=neutral Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Hpj9n6Gqnz3cG3 for ; Wed, 10 Nov 2021 09:21:01 +1100 (AEDT) Received: by mail.kernel.org (Postfix) with ESMTPSA id 6F98661A6C; Tue, 9 Nov 2021 22:20:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636496460; bh=CEcvv+vzt12RPoJlIolDN3gbYICVproW8INlvGSj9bM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZhXr5rLlnEM0IJQNbq4hv539RZSVnssDV9F1jsg15eRPRrvAyL46kWUwRiEjRDrB4 aSJtBPxh/DFI3VUeWq+Ed39mcowgv+kKeFst8Ro4B8jsyVTekAEoGsMfeHuvSB4yWB 0ww5dqldUPWUkKKZNp9qfFLj44OY/zeNem0xZAF2pJMI4seYrOflJlCXb0jDrURQvY KmTkyocJtUsqwa7ZhuODHbwroHb2RuBlz124tEoJZmF46WXIuZAAaUgVoontDry3aR /hnK7eVcCrL6cKuzPrAffOJeDnXGkl3ClYmPrdzlIqiTpj1bceIMRNmWpuBZNxmiL8 PadM29uTEv6Dw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 5.14 74/75] powerpc/8xx: Fix Oops with STRICT_KERNEL_RWX without DEBUG_RODATA_TEST Date: Tue, 9 Nov 2021 17:19:04 -0500 Message-Id: <20211109221905.1234094-74-sashal@kernel.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211109221905.1234094-1-sashal@kernel.org> References: <20211109221905.1234094-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sasha Levin , paulus@samba.org, gregkh@linuxfoundation.org, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Christophe Leroy [ Upstream commit c12ab8dbc492b992e1ea717db933cee568780c47 ] Until now, all tests involving CONFIG_STRICT_KERNEL_RWX were done with DEBUG_RODATA_TEST to check the result. But now that CONFIG_STRICT_KERNEL_RWX is selected by default, it came without CONFIG_DEBUG_RODATA_TEST and led to the following Oops [ 6.830908] Freeing unused kernel image (initmem) memory: 352K [ 6.840077] BUG: Unable to handle kernel data access on write at 0xc1285200 [ 6.846836] Faulting instruction address: 0xc0004b6c [ 6.851745] Oops: Kernel access of bad area, sig: 11 [#1] [ 6.857075] BE PAGE_SIZE=16K PREEMPT CMPC885 [ 6.861348] SAF3000 DIE NOTIFICATION [ 6.864830] CPU: 0 PID: 1 Comm: swapper Not tainted 5.15.0-rc5-s3k-dev-02255-g2747d7b7916f #451 [ 6.873429] NIP: c0004b6c LR: c0004b60 CTR: 00000000 [ 6.878419] REGS: c902be60 TRAP: 0300 Not tainted (5.15.0-rc5-s3k-dev-02255-g2747d7b7916f) [ 6.886852] MSR: 00009032 CR: 53000335 XER: 8000ff40 [ 6.893564] DAR: c1285200 DSISR: 82000000 [ 6.893564] GPR00: 0c000000 c902bf20 c20f4000 08000000 00000001 04001f00 c1800000 00000035 [ 6.893564] GPR08: ff0001ff c1280000 00000002 c0004b60 00001000 00000000 c0004b1c 00000000 [ 6.893564] GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 6.893564] GPR24: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 c1060000 [ 6.932034] NIP [c0004b6c] kernel_init+0x50/0x138 [ 6.936682] LR [c0004b60] kernel_init+0x44/0x138 [ 6.941245] Call Trace: [ 6.943653] [c902bf20] [c0004b60] kernel_init+0x44/0x138 (unreliable) [ 6.950022] [c902bf30] [c001122c] ret_from_kernel_thread+0x5c/0x64 [ 6.956135] Instruction dump: [ 6.959060] 48ffc521 48045469 4800d8cd 3d20c086 89295fa0 2c090000 41820058 480796c9 [ 6.966890] 4800e48d 3d20c128 39400002 3fe0c106 <91495200> 3bff8000 4806fa1d 481f7d75 [ 6.974902] ---[ end trace 1e397bacba4aa610 ]--- 0xc1285200 corresponds to 'system_state' global var that the kernel is trying to set to SYSTEM_RUNNING. This var is above the RO/RW limit so it shouldn't Oops. It oopses because the dirty bit is missing. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/3d5800b0bbcd7b19761b98f50421358667b45331.1635520232.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin --- arch/powerpc/kernel/head_8xx.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 9bdb95f5694f7..2d596881b70e7 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -755,7 +755,7 @@ _GLOBAL(mmu_pin_tlb) cmplw r6, r9 bdnzt lt, 2b -4: LOAD_REG_IMMEDIATE(r8, 0xf0 | _PAGE_SPS | _PAGE_SH | _PAGE_PRESENT) +4: LOAD_REG_IMMEDIATE(r8, 0xf0 | _PAGE_DIRTY | _PAGE_SPS | _PAGE_SH | _PAGE_PRESENT) 2: ori r0, r6, MD_EVALID mtspr SPRN_MD_CTR, r5 mtspr SPRN_MD_EPN, r0 -- 2.33.0