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=-5.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 DEE20C4332D for ; Fri, 20 Mar 2020 00:16:31 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 89FD720754 for ; Fri, 20 Mar 2020 00:16:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ozlabs.org header.i=@ozlabs.org header.b="pZ8L8pul" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 89FD720754 Authentication-Results: mail.kernel.org; dmarc=pass (p=none dis=none) header.from=ozlabs.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48k47x20GhzDr4C for ; Fri, 20 Mar 2020 11:16:29 +1100 (AEDT) Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 48k45x0KWSzDr1V for ; Fri, 20 Mar 2020 11:14:45 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=ozlabs.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=ozlabs.org header.i=@ozlabs.org header.a=rsa-sha256 header.s=201707 header.b=pZ8L8pul; dkim-atps=neutral Received: by ozlabs.org (Postfix, from userid 1003) id 48k45w5ZpRz9sSN; Fri, 20 Mar 2020 11:14:44 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ozlabs.org; s=201707; t=1584663284; bh=qtcvlr7LWDX6x5OzXfhtLW+Qxyrt5hsbj/WjOzdsVQU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pZ8L8pulD9TTUG5e6Pz1ZP/Js7CWeY/O4NngTwgY8j2qxTSR+hRcSzynE2Fm9Fkg+ wlc6h6Skb/hUXNQhWKim9AiqXw2Bbu2kcrq9lrVf8wf99KGtHjZq6bCJQ4l9gtnqJA SicGAuwqwIbQK+A+sHaCGZXmqFSi45tIarz9vh4ETxvlKyGE3QXc1iYzUkXWAO3Pb1 3mOjGoSVXGPOxpfuS0zBmDjyQ0GTLJpiTmJ5WWk2ftR64lhmnNJxRuZ421Xtuc09qR SAcYv64j9WpCWEYGsxIscD6344AFgHD95oNXnPQgbddeYHx0gyIXbjGmueiCxLZW6G HNCR0oOY8ru5A== Date: Fri, 20 Mar 2020 11:14:40 +1100 From: Paul Mackerras To: Fabiano Rosas Subject: Re: [PATCH] KVM: PPC: Book3S HV: Skip kvmppc_uvmem_free if Ultravisor is not supported Message-ID: <20200320001440.GG3260@blackberry> References: <20200319225510.945603-1-farosas@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200319225510.945603-1-farosas@linux.ibm.com> User-Agent: Mutt/1.5.24 (2015-08-30) 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: linuxppc-dev@lists.ozlabs.org, groug@kaod.org, kvm-ppc@vger.kernel.org, bharata@linux.ibm.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Thu, Mar 19, 2020 at 07:55:10PM -0300, Fabiano Rosas wrote: > kvmppc_uvmem_init checks for Ultravisor support and returns early if > it is not present. Calling kvmppc_uvmem_free at module exit will cause > an Oops: > > $ modprobe -r kvm-hv > > Oops: Kernel access of bad area, sig: 11 [#1] > > NIP: c000000000789e90 LR: c000000000789e8c CTR: c000000000401030 > REGS: c000003fa7bab9a0 TRAP: 0300 Not tainted (5.6.0-rc6-00033-g6c90b86a745a-dirty) > MSR: 9000000000009033 CR: 24002282 XER: 00000000 > CFAR: c000000000dae880 DAR: 0000000000000008 DSISR: 40000000 IRQMASK: 1 > GPR00: c000000000789e8c c000003fa7babc30 c0000000016fe500 0000000000000000 > GPR04: 0000000000000000 0000000000000006 0000000000000000 c000003faf205c00 > GPR08: 0000000000000000 0000000000000001 000000008000002d c00800000ddde140 > GPR12: c000000000401030 c000003ffffd9080 0000000000000001 0000000000000000 > GPR16: 0000000000000000 0000000000000000 000000013aad0074 000000013aaac978 > GPR20: 000000013aad0070 0000000000000000 00007fffd1b37158 0000000000000000 > GPR24: 000000014fef0d58 0000000000000000 000000014fef0cf0 0000000000000001 > GPR28: 0000000000000000 0000000000000000 c0000000018b2a60 0000000000000000 > NIP [c000000000789e90] percpu_ref_kill_and_confirm+0x40/0x170 > LR [c000000000789e8c] percpu_ref_kill_and_confirm+0x3c/0x170 > Call Trace: > [c000003fa7babc30] [c000003faf2064d4] 0xc000003faf2064d4 (unreliable) > [c000003fa7babcb0] [c000000000400e8c] dev_pagemap_kill+0x6c/0x80 > [c000003fa7babcd0] [c000000000401064] memunmap_pages+0x34/0x2f0 > [c000003fa7babd50] [c00800000dddd548] kvmppc_uvmem_free+0x30/0x80 [kvm_hv] > [c000003fa7babd80] [c00800000ddcef18] kvmppc_book3s_exit_hv+0x20/0x78 [kvm_hv] > [c000003fa7babda0] [c0000000002084d0] sys_delete_module+0x1d0/0x2c0 > [c000003fa7babe20] [c00000000000b9d0] system_call+0x5c/0x68 > Instruction dump: > 3fc2001b fb81ffe0 fba1ffe8 fbe1fff8 7c7f1b78 7c9c2378 3bde4560 7fc3f378 > f8010010 f821ff81 486249a1 60000000 7c7d1b78 712a0002 40820084 > ---[ end trace 5774ef4dc2c98279 ]--- > > So this patch checks if kvmppc_uvmem_init actually allocated anything > before running kvmppc_uvmem_free. > > Fixes: ca9f4942670c ("KVM: PPC: Book3S HV: Support for running secure guests") > Reported-by: Greg Kurz > Signed-off-by: Fabiano Rosas Good catch! This should be Cc: stable@vger.kernel.org # v5.5+ Acked-by: Paul Mackerras Paul.