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 0B7DDC433F5 for ; Mon, 11 Oct 2021 13:59:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4E3660C49 for ; Mon, 11 Oct 2021 13:59:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238490AbhJKOBF (ORCPT ); Mon, 11 Oct 2021 10:01:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:50652 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238066AbhJKN7C (ORCPT ); Mon, 11 Oct 2021 09:59:02 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EA40961183; Mon, 11 Oct 2021 13:55:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1633960538; bh=tpmhQVG3ZBhbyzf8WNpZ7saT8fNnqSQjsr2XDdzT60A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uLgXEBCMX9QKIaXVai4uBUXs07Ot71PG87F9MKKBfDF0v9XMolB8Bt+S1zeLus/gD Ff7NCNa4hrKZM6uWu/7UjfYUku5JUiPdG1lpYVLoX8kCFHC08gVwelpxbJ+Tj2rUNs 5uwiLpCmIRSwQI7Gc/OuuLRhhzUsOmqvt6SNEhkk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nicholas Piggin , Michael Ellerman , Sasha Levin Subject: [PATCH 5.10 75/83] powerpc/64s: fix program check interrupt emergency stack path Date: Mon, 11 Oct 2021 15:46:35 +0200 Message-Id: <20211011134510.969579773@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211011134508.362906295@linuxfoundation.org> References: <20211011134508.362906295@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nicholas Piggin [ Upstream commit 3e607dc4df180b72a38e75030cb0f94d12808712 ] Emergency stack path was jumping into a 3: label inside the __GEN_COMMON_BODY macro for the normal path after it had finished, rather than jumping over it. By a small miracle this is the correct place to build up a new interrupt frame with the existing stack pointer, so things basically worked okay with an added weird looking 700 trap frame on top (which had the wrong ->nip so it didn't decode bug messages either). Fix this by avoiding using numeric labels when jumping over non-trivial macros. Before: LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 0 PID: 88 Comm: sh Not tainted 5.15.0-rc2-00034-ge057cdade6e5 #2637 NIP: 7265677368657265 LR: c00000000006c0c8 CTR: c0000000000097f0 REGS: c0000000fffb3a50 TRAP: 0700 Not tainted MSR: 9000000000021031 CR: 00000700 XER: 20040000 CFAR: c0000000000098b0 IRQMASK: 0 GPR00: c00000000006c964 c0000000fffb3cf0 c000000001513800 0000000000000000 GPR04: 0000000048ab0778 0000000042000000 0000000000000000 0000000000001299 GPR08: 000001e447c718ec 0000000022424282 0000000000002710 c00000000006bee8 GPR12: 9000000000009033 c0000000016b0000 00000000000000b0 0000000000000001 GPR16: 0000000000000000 0000000000000002 0000000000000000 0000000000000ff8 GPR20: 0000000000001fff 0000000000000007 0000000000000080 00007fff89d90158 GPR24: 0000000002000000 0000000002000000 0000000000000255 0000000000000300 GPR28: c000000001270000 0000000042000000 0000000048ab0778 c000000080647e80 NIP [7265677368657265] 0x7265677368657265 LR [c00000000006c0c8] ___do_page_fault+0x3f8/0xb10 Call Trace: [c0000000fffb3cf0] [c00000000000bdac] soft_nmi_common+0x13c/0x1d0 (unreliable) --- interrupt: 700 at decrementer_common_virt+0xb8/0x230 NIP: c0000000000098b8 LR: c00000000006c0c8 CTR: c0000000000097f0 REGS: c0000000fffb3d60 TRAP: 0700 Not tainted MSR: 9000000000021031 CR: 22424282 XER: 20040000 CFAR: c0000000000098b0 IRQMASK: 0 GPR00: c00000000006c964 0000000000002400 c000000001513800 0000000000000000 GPR04: 0000000048ab0778 0000000042000000 0000000000000000 0000000000001299 GPR08: 000001e447c718ec 0000000022424282 0000000000002710 c00000000006bee8 GPR12: 9000000000009033 c0000000016b0000 00000000000000b0 0000000000000001 GPR16: 0000000000000000 0000000000000002 0000000000000000 0000000000000ff8 GPR20: 0000000000001fff 0000000000000007 0000000000000080 00007fff89d90158 GPR24: 0000000002000000 0000000002000000 0000000000000255 0000000000000300 GPR28: c000000001270000 0000000042000000 0000000048ab0778 c000000080647e80 NIP [c0000000000098b8] decrementer_common_virt+0xb8/0x230 LR [c00000000006c0c8] ___do_page_fault+0x3f8/0xb10 --- interrupt: 700 Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX ---[ end trace 6d28218e0cc3c949 ]--- After: ------------[ cut here ]------------ kernel BUG at arch/powerpc/kernel/exceptions-64s.S:491! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 0 PID: 88 Comm: login Not tainted 5.15.0-rc2-00034-ge057cdade6e5-dirty #2638 NIP: c0000000000098b8 LR: c00000000006bf04 CTR: c0000000000097f0 REGS: c0000000fffb3d60 TRAP: 0700 Not tainted MSR: 9000000000021031 CR: 24482227 XER: 00040000 CFAR: c0000000000098b0 IRQMASK: 0 GPR00: c00000000006bf04 0000000000002400 c000000001513800 c000000001271868 GPR04: 00000000100f0d29 0000000042000000 0000000000000007 0000000000000009 GPR08: 00000000100f0d29 0000000024482227 0000000000002710 c000000000181b3c GPR12: 9000000000009033 c0000000016b0000 00000000100f0d29 c000000005b22f00 GPR16: 00000000ffff0000 0000000000000001 0000000000000009 00000000100eed90 GPR20: 00000000100eed90 0000000010000000 000000001000a49c 00000000100f1430 GPR24: c000000001271868 0000000002000000 0000000000000215 0000000000000300 GPR28: c000000001271800 0000000042000000 00000000100f0d29 c000000080647860 NIP [c0000000000098b8] decrementer_common_virt+0xb8/0x230 LR [c00000000006bf04] ___do_page_fault+0x234/0xb10 Call Trace: Instruction dump: 4182000c 39400001 48000008 894d0932 714a0001 39400008 408225fc 718a4000 7c2a0b78 3821fcf0 41c20008 e82d0910 <0981fcf0> f92101a0 f9610170 f9810178 ---[ end trace a5dbd1f5ea4ccc51 ]--- Fixes: 0a882e28468f4 ("powerpc/64s/exception: remove bad stack branch") Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211004145642.1331214-2-npiggin@gmail.com Signed-off-by: Sasha Levin --- arch/powerpc/kernel/exceptions-64s.S | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 9d3b468bd2d7..10df278dc3fb 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1715,27 +1715,30 @@ EXC_COMMON_BEGIN(program_check_common) */ andi. r10,r12,MSR_PR - bne 2f /* If userspace, go normal path */ + bne .Lnormal_stack /* If userspace, go normal path */ andis. r10,r12,(SRR1_PROGTM)@h - bne 1f /* If TM, emergency */ + bne .Lemergency_stack /* If TM, emergency */ cmpdi r1,-INT_FRAME_SIZE /* check if r1 is in userspace */ - blt 2f /* normal path if not */ + blt .Lnormal_stack /* normal path if not */ /* Use the emergency stack */ -1: andi. r10,r12,MSR_PR /* Set CR0 correctly for label */ +.Lemergency_stack: + andi. r10,r12,MSR_PR /* Set CR0 correctly for label */ /* 3 in EXCEPTION_PROLOG_COMMON */ mr r10,r1 /* Save r1 */ ld r1,PACAEMERGSP(r13) /* Use emergency stack */ subi r1,r1,INT_FRAME_SIZE /* alloc stack frame */ __ISTACK(program_check)=0 __GEN_COMMON_BODY program_check - b 3f -2: + b .Ldo_program_check + +.Lnormal_stack: __ISTACK(program_check)=1 __GEN_COMMON_BODY program_check -3: + +.Ldo_program_check: addi r3,r1,STACK_FRAME_OVERHEAD bl program_check_exception REST_NVGPRS(r1) /* instruction emulation may change GPRs */ -- 2.33.0