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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 8ED71C47255 for ; Mon, 11 May 2020 11:15:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 54AE320722 for ; Mon, 11 May 2020 11:15:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ellerman.id.au header.i=@ellerman.id.au header.b="JYTwqrWT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729465AbgEKLPm (ORCPT ); Mon, 11 May 2020 07:15:42 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:34741 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726438AbgEKLPl (ORCPT ); Mon, 11 May 2020 07:15:41 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 49LJJV56jgz9sPF; Mon, 11 May 2020 21:15:38 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1589195738; bh=6jMBGt6cCuxG5ogHappx3RvOBhGXUdUBt4srA2FzeVQ=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=JYTwqrWTtatawX9E9uCWvSCMdxzbkYKyGUKiRXi2FvNjjN22Zi7b2VYkhjEYqr6Zs gpefe7juiqlnLR23hGKNV4nJBW1KwxcokfhrriOPXi+/0HVXRsuEMvASGwZE4qh/F4 o9A//EnFaS+D5iMUhDiakpPbVVdBe407TFKLg344kzdrvzLuTvYonCg8URRl6pxzSi f7yWo60ABiuz6jzxYuUn4tAgt5BvpJUTO8vqUF1ZCCaU63BvSeczs7m+hVSQmopm+g OubQRRbncGIVGb7WxI5SR+UNnXSvI494vS7ocfn/W9ETbahHmKeBbnDp+NlGaoibk5 dRIyyp023LHuQ== From: Michael Ellerman To: Qian Cai Cc: paulus@ozlabs.org, benh@kernel.crashing.org, catalin.marinas@arm.com, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Qian Cai Subject: Re: [PATCH] powerpc/kvm: silence kmemleak false positives In-Reply-To: <20200509015538.3183-1-cai@lca.pw> References: <20200509015538.3183-1-cai@lca.pw> Date: Mon, 11 May 2020 21:15:55 +1000 Message-ID: <87y2pybu38.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Qian Cai writes: > kvmppc_pmd_alloc() and kvmppc_pte_alloc() allocate some memory but then > pud_populate() and pmd_populate() will use __pa() to reference the newly > allocated memory. The same is in xive_native_provision_pages(). > > Since kmemleak is unable to track the physical memory resulting in false > positives, silence those by using kmemleak_ignore(). There is kmemleak_alloc_phys(), which according to the docs can be used for tracking a phys address. Did you try that? cheers > unreferenced object 0xc000201c382a1000 (size 4096): > comm "qemu-kvm", pid 124828, jiffies 4295733767 (age 341.250s) > hex dump (first 32 bytes): > c0 00 20 09 f4 60 03 87 c0 00 20 10 72 a0 03 87 .. ..`.... .r... > c0 00 20 0e 13 a0 03 87 c0 00 20 1b dc c0 03 87 .. ....... ..... > backtrace: > [<000000004cc2790f>] kvmppc_create_pte+0x838/0xd20 [kvm_hv] > kvmppc_pmd_alloc at arch/powerpc/kvm/book3s_64_mmu_radix.c:366 > (inlined by) kvmppc_create_pte at arch/powerpc/kvm/book3s_64_mmu_radix.c:590 > [<00000000d123c49a>] kvmppc_book3s_instantiate_page+0x2e0/0x8c0 [kvm_hv] > [<00000000bb549087>] kvmppc_book3s_radix_page_fault+0x1b4/0x2b0 [kvm_hv] > [<0000000086dddc0e>] kvmppc_book3s_hv_page_fault+0x214/0x12a0 [kvm_hv] > [<000000005ae9ccc2>] kvmppc_vcpu_run_hv+0xc5c/0x15f0 [kvm_hv] > [<00000000d22162ff>] kvmppc_vcpu_run+0x34/0x48 [kvm] > [<00000000d6953bc4>] kvm_arch_vcpu_ioctl_run+0x314/0x420 [kvm] > [<000000002543dd54>] kvm_vcpu_ioctl+0x33c/0x950 [kvm] > [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 > [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 > [<000000004afc4310>] system_call_exception+0x114/0x1e0 > [<00000000fb70a873>] system_call_common+0xf0/0x278 > unreferenced object 0xc0002001f0c03900 (size 256): > comm "qemu-kvm", pid 124830, jiffies 4295735235 (age 326.570s) > hex dump (first 32 bytes): > c0 00 20 10 fa a0 03 87 c0 00 20 10 fa a1 03 87 .. ....... ..... > c0 00 20 10 fa a2 03 87 c0 00 20 10 fa a3 03 87 .. ....... ..... > backtrace: > [<0000000023f675b8>] kvmppc_create_pte+0x854/0xd20 [kvm_hv] > kvmppc_pte_alloc at arch/powerpc/kvm/book3s_64_mmu_radix.c:356 > (inlined by) kvmppc_create_pte at arch/powerpc/kvm/book3s_64_mmu_radix.c:593 > [<00000000d123c49a>] kvmppc_book3s_instantiate_page+0x2e0/0x8c0 [kvm_hv] > [<00000000bb549087>] kvmppc_book3s_radix_page_fault+0x1b4/0x2b0 [kvm_hv] > [<0000000086dddc0e>] kvmppc_book3s_hv_page_fault+0x214/0x12a0 [kvm_hv] > [<000000005ae9ccc2>] kvmppc_vcpu_run_hv+0xc5c/0x15f0 [kvm_hv] > [<00000000d22162ff>] kvmppc_vcpu_run+0x34/0x48 [kvm] > [<00000000d6953bc4>] kvm_arch_vcpu_ioctl_run+0x314/0x420 [kvm] > [<000000002543dd54>] kvm_vcpu_ioctl+0x33c/0x950 [kvm] > [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 > [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 > [<000000004afc4310>] system_call_exception+0x114/0x1e0 > [<00000000fb70a873>] system_call_common+0xf0/0x278 > unreferenced object 0xc000201b53e90000 (size 65536): > comm "qemu-kvm", pid 124557, jiffies 4295650285 (age 364.370s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<00000000acc2fb77>] xive_native_alloc_vp_block+0x168/0x210 > xive_native_provision_pages at arch/powerpc/sysdev/xive/native.c:645 > (inlined by) xive_native_alloc_vp_block at arch/powerpc/sysdev/xive/native.c:674 > [<000000004d5c7964>] kvmppc_xive_compute_vp_id+0x20c/0x3b0 [kvm] > [<0000000055317cd2>] kvmppc_xive_connect_vcpu+0xa4/0x4a0 [kvm] > [<0000000093dfc014>] kvm_arch_vcpu_ioctl+0x388/0x508 [kvm] > [<00000000d25aea0f>] kvm_vcpu_ioctl+0x15c/0x950 [kvm] > [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 > [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 > [<000000004afc4310>] system_call_exception+0x114/0x1e0 > [<00000000fb70a873>] system_call_common+0xf0/0x278 > > Signed-off-by: Qian Cai > --- > arch/powerpc/kvm/book3s_64_mmu_radix.c | 16 ++++++++++++++-- > arch/powerpc/sysdev/xive/native.c | 4 ++++ > 2 files changed, 18 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c > index aa12cd4078b3..bc6c1aa3d0e9 100644 > --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c > +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c > @@ -353,7 +353,13 @@ static struct kmem_cache *kvm_pmd_cache; > > static pte_t *kvmppc_pte_alloc(void) > { > - return kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL); > + pte_t *pte; > + > + pte = kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL); > + /* pmd_populate() will only reference _pa(pte). */ > + kmemleak_ignore(pte); > + > + return pte; > } > > static void kvmppc_pte_free(pte_t *ptep) > @@ -363,7 +369,13 @@ static void kvmppc_pte_free(pte_t *ptep) > > static pmd_t *kvmppc_pmd_alloc(void) > { > - return kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL); > + pmd_t *pmd; > + > + pmd = kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL); > + /* pud_populate() will only reference _pa(pmd). */ > + kmemleak_ignore(pmd); > + > + return pmd; > } > > static void kvmppc_pmd_free(pmd_t *pmdp) > diff --git a/arch/powerpc/sysdev/xive/native.c b/arch/powerpc/sysdev/xive/native.c > index 5218fdc4b29a..2d19f28967a6 100644 > --- a/arch/powerpc/sysdev/xive/native.c > +++ b/arch/powerpc/sysdev/xive/native.c > @@ -18,6 +18,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -647,6 +648,9 @@ static bool xive_native_provision_pages(void) > pr_err("Failed to allocate provisioning page\n"); > return false; > } > + /* Kmemleak is unable to track the physical address. */ > + kmemleak_ignore(p); > + > opal_xive_donate_page(chip, __pa(p)); > } > return true; > -- > 2.21.0 (Apple Git-122.2) 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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 58B67C47255 for ; Mon, 11 May 2020 11:17:56 +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 F3B2720722 for ; Mon, 11 May 2020 11:17:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ellerman.id.au header.i=@ellerman.id.au header.b="JYTwqrWT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F3B2720722 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49LJM52p5bzDqjH for ; Mon, 11 May 2020 21:17:53 +1000 (AEST) 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 49LJJX3nlQzDqg5 for ; Mon, 11 May 2020 21:15:40 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=JYTwqrWT; dkim-atps=neutral Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 49LJJV56jgz9sPF; Mon, 11 May 2020 21:15:38 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1589195738; bh=6jMBGt6cCuxG5ogHappx3RvOBhGXUdUBt4srA2FzeVQ=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=JYTwqrWTtatawX9E9uCWvSCMdxzbkYKyGUKiRXi2FvNjjN22Zi7b2VYkhjEYqr6Zs gpefe7juiqlnLR23hGKNV4nJBW1KwxcokfhrriOPXi+/0HVXRsuEMvASGwZE4qh/F4 o9A//EnFaS+D5iMUhDiakpPbVVdBe407TFKLg344kzdrvzLuTvYonCg8URRl6pxzSi f7yWo60ABiuz6jzxYuUn4tAgt5BvpJUTO8vqUF1ZCCaU63BvSeczs7m+hVSQmopm+g OubQRRbncGIVGb7WxI5SR+UNnXSvI494vS7ocfn/W9ETbahHmKeBbnDp+NlGaoibk5 dRIyyp023LHuQ== From: Michael Ellerman To: Qian Cai Subject: Re: [PATCH] powerpc/kvm: silence kmemleak false positives In-Reply-To: <20200509015538.3183-1-cai@lca.pw> References: <20200509015538.3183-1-cai@lca.pw> Date: Mon, 11 May 2020 21:15:55 +1000 Message-ID: <87y2pybu38.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain 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: linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, Qian Cai , catalin.marinas@arm.com, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Qian Cai writes: > kvmppc_pmd_alloc() and kvmppc_pte_alloc() allocate some memory but then > pud_populate() and pmd_populate() will use __pa() to reference the newly > allocated memory. The same is in xive_native_provision_pages(). > > Since kmemleak is unable to track the physical memory resulting in false > positives, silence those by using kmemleak_ignore(). There is kmemleak_alloc_phys(), which according to the docs can be used for tracking a phys address. Did you try that? cheers > unreferenced object 0xc000201c382a1000 (size 4096): > comm "qemu-kvm", pid 124828, jiffies 4295733767 (age 341.250s) > hex dump (first 32 bytes): > c0 00 20 09 f4 60 03 87 c0 00 20 10 72 a0 03 87 .. ..`.... .r... > c0 00 20 0e 13 a0 03 87 c0 00 20 1b dc c0 03 87 .. ....... ..... > backtrace: > [<000000004cc2790f>] kvmppc_create_pte+0x838/0xd20 [kvm_hv] > kvmppc_pmd_alloc at arch/powerpc/kvm/book3s_64_mmu_radix.c:366 > (inlined by) kvmppc_create_pte at arch/powerpc/kvm/book3s_64_mmu_radix.c:590 > [<00000000d123c49a>] kvmppc_book3s_instantiate_page+0x2e0/0x8c0 [kvm_hv] > [<00000000bb549087>] kvmppc_book3s_radix_page_fault+0x1b4/0x2b0 [kvm_hv] > [<0000000086dddc0e>] kvmppc_book3s_hv_page_fault+0x214/0x12a0 [kvm_hv] > [<000000005ae9ccc2>] kvmppc_vcpu_run_hv+0xc5c/0x15f0 [kvm_hv] > [<00000000d22162ff>] kvmppc_vcpu_run+0x34/0x48 [kvm] > [<00000000d6953bc4>] kvm_arch_vcpu_ioctl_run+0x314/0x420 [kvm] > [<000000002543dd54>] kvm_vcpu_ioctl+0x33c/0x950 [kvm] > [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 > [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 > [<000000004afc4310>] system_call_exception+0x114/0x1e0 > [<00000000fb70a873>] system_call_common+0xf0/0x278 > unreferenced object 0xc0002001f0c03900 (size 256): > comm "qemu-kvm", pid 124830, jiffies 4295735235 (age 326.570s) > hex dump (first 32 bytes): > c0 00 20 10 fa a0 03 87 c0 00 20 10 fa a1 03 87 .. ....... ..... > c0 00 20 10 fa a2 03 87 c0 00 20 10 fa a3 03 87 .. ....... ..... > backtrace: > [<0000000023f675b8>] kvmppc_create_pte+0x854/0xd20 [kvm_hv] > kvmppc_pte_alloc at arch/powerpc/kvm/book3s_64_mmu_radix.c:356 > (inlined by) kvmppc_create_pte at arch/powerpc/kvm/book3s_64_mmu_radix.c:593 > [<00000000d123c49a>] kvmppc_book3s_instantiate_page+0x2e0/0x8c0 [kvm_hv] > [<00000000bb549087>] kvmppc_book3s_radix_page_fault+0x1b4/0x2b0 [kvm_hv] > [<0000000086dddc0e>] kvmppc_book3s_hv_page_fault+0x214/0x12a0 [kvm_hv] > [<000000005ae9ccc2>] kvmppc_vcpu_run_hv+0xc5c/0x15f0 [kvm_hv] > [<00000000d22162ff>] kvmppc_vcpu_run+0x34/0x48 [kvm] > [<00000000d6953bc4>] kvm_arch_vcpu_ioctl_run+0x314/0x420 [kvm] > [<000000002543dd54>] kvm_vcpu_ioctl+0x33c/0x950 [kvm] > [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 > [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 > [<000000004afc4310>] system_call_exception+0x114/0x1e0 > [<00000000fb70a873>] system_call_common+0xf0/0x278 > unreferenced object 0xc000201b53e90000 (size 65536): > comm "qemu-kvm", pid 124557, jiffies 4295650285 (age 364.370s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<00000000acc2fb77>] xive_native_alloc_vp_block+0x168/0x210 > xive_native_provision_pages at arch/powerpc/sysdev/xive/native.c:645 > (inlined by) xive_native_alloc_vp_block at arch/powerpc/sysdev/xive/native.c:674 > [<000000004d5c7964>] kvmppc_xive_compute_vp_id+0x20c/0x3b0 [kvm] > [<0000000055317cd2>] kvmppc_xive_connect_vcpu+0xa4/0x4a0 [kvm] > [<0000000093dfc014>] kvm_arch_vcpu_ioctl+0x388/0x508 [kvm] > [<00000000d25aea0f>] kvm_vcpu_ioctl+0x15c/0x950 [kvm] > [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 > [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 > [<000000004afc4310>] system_call_exception+0x114/0x1e0 > [<00000000fb70a873>] system_call_common+0xf0/0x278 > > Signed-off-by: Qian Cai > --- > arch/powerpc/kvm/book3s_64_mmu_radix.c | 16 ++++++++++++++-- > arch/powerpc/sysdev/xive/native.c | 4 ++++ > 2 files changed, 18 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c > index aa12cd4078b3..bc6c1aa3d0e9 100644 > --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c > +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c > @@ -353,7 +353,13 @@ static struct kmem_cache *kvm_pmd_cache; > > static pte_t *kvmppc_pte_alloc(void) > { > - return kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL); > + pte_t *pte; > + > + pte = kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL); > + /* pmd_populate() will only reference _pa(pte). */ > + kmemleak_ignore(pte); > + > + return pte; > } > > static void kvmppc_pte_free(pte_t *ptep) > @@ -363,7 +369,13 @@ static void kvmppc_pte_free(pte_t *ptep) > > static pmd_t *kvmppc_pmd_alloc(void) > { > - return kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL); > + pmd_t *pmd; > + > + pmd = kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL); > + /* pud_populate() will only reference _pa(pmd). */ > + kmemleak_ignore(pmd); > + > + return pmd; > } > > static void kvmppc_pmd_free(pmd_t *pmdp) > diff --git a/arch/powerpc/sysdev/xive/native.c b/arch/powerpc/sysdev/xive/native.c > index 5218fdc4b29a..2d19f28967a6 100644 > --- a/arch/powerpc/sysdev/xive/native.c > +++ b/arch/powerpc/sysdev/xive/native.c > @@ -18,6 +18,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -647,6 +648,9 @@ static bool xive_native_provision_pages(void) > pr_err("Failed to allocate provisioning page\n"); > return false; > } > + /* Kmemleak is unable to track the physical address. */ > + kmemleak_ignore(p); > + > opal_xive_donate_page(chip, __pa(p)); > } > return true; > -- > 2.21.0 (Apple Git-122.2) From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Ellerman Date: Mon, 11 May 2020 11:15:55 +0000 Subject: Re: [PATCH] powerpc/kvm: silence kmemleak false positives Message-Id: <87y2pybu38.fsf@mpe.ellerman.id.au> List-Id: References: <20200509015538.3183-1-cai@lca.pw> In-Reply-To: <20200509015538.3183-1-cai@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Qian Cai Cc: paulus@ozlabs.org, benh@kernel.crashing.org, catalin.marinas@arm.com, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Qian Cai Qian Cai writes: > kvmppc_pmd_alloc() and kvmppc_pte_alloc() allocate some memory but then > pud_populate() and pmd_populate() will use __pa() to reference the newly > allocated memory. The same is in xive_native_provision_pages(). > > Since kmemleak is unable to track the physical memory resulting in false > positives, silence those by using kmemleak_ignore(). There is kmemleak_alloc_phys(), which according to the docs can be used for tracking a phys address. Did you try that? cheers > unreferenced object 0xc000201c382a1000 (size 4096): > comm "qemu-kvm", pid 124828, jiffies 4295733767 (age 341.250s) > hex dump (first 32 bytes): > c0 00 20 09 f4 60 03 87 c0 00 20 10 72 a0 03 87 .. ..`.... .r... > c0 00 20 0e 13 a0 03 87 c0 00 20 1b dc c0 03 87 .. ....... ..... > backtrace: > [<000000004cc2790f>] kvmppc_create_pte+0x838/0xd20 [kvm_hv] > kvmppc_pmd_alloc at arch/powerpc/kvm/book3s_64_mmu_radix.c:366 > (inlined by) kvmppc_create_pte at arch/powerpc/kvm/book3s_64_mmu_radix.c:590 > [<00000000d123c49a>] kvmppc_book3s_instantiate_page+0x2e0/0x8c0 [kvm_hv] > [<00000000bb549087>] kvmppc_book3s_radix_page_fault+0x1b4/0x2b0 [kvm_hv] > [<0000000086dddc0e>] kvmppc_book3s_hv_page_fault+0x214/0x12a0 [kvm_hv] > [<000000005ae9ccc2>] kvmppc_vcpu_run_hv+0xc5c/0x15f0 [kvm_hv] > [<00000000d22162ff>] kvmppc_vcpu_run+0x34/0x48 [kvm] > [<00000000d6953bc4>] kvm_arch_vcpu_ioctl_run+0x314/0x420 [kvm] > [<000000002543dd54>] kvm_vcpu_ioctl+0x33c/0x950 [kvm] > [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 > [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 > [<000000004afc4310>] system_call_exception+0x114/0x1e0 > [<00000000fb70a873>] system_call_common+0xf0/0x278 > unreferenced object 0xc0002001f0c03900 (size 256): > comm "qemu-kvm", pid 124830, jiffies 4295735235 (age 326.570s) > hex dump (first 32 bytes): > c0 00 20 10 fa a0 03 87 c0 00 20 10 fa a1 03 87 .. ....... ..... > c0 00 20 10 fa a2 03 87 c0 00 20 10 fa a3 03 87 .. ....... ..... > backtrace: > [<0000000023f675b8>] kvmppc_create_pte+0x854/0xd20 [kvm_hv] > kvmppc_pte_alloc at arch/powerpc/kvm/book3s_64_mmu_radix.c:356 > (inlined by) kvmppc_create_pte at arch/powerpc/kvm/book3s_64_mmu_radix.c:593 > [<00000000d123c49a>] kvmppc_book3s_instantiate_page+0x2e0/0x8c0 [kvm_hv] > [<00000000bb549087>] kvmppc_book3s_radix_page_fault+0x1b4/0x2b0 [kvm_hv] > [<0000000086dddc0e>] kvmppc_book3s_hv_page_fault+0x214/0x12a0 [kvm_hv] > [<000000005ae9ccc2>] kvmppc_vcpu_run_hv+0xc5c/0x15f0 [kvm_hv] > [<00000000d22162ff>] kvmppc_vcpu_run+0x34/0x48 [kvm] > [<00000000d6953bc4>] kvm_arch_vcpu_ioctl_run+0x314/0x420 [kvm] > [<000000002543dd54>] kvm_vcpu_ioctl+0x33c/0x950 [kvm] > [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 > [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 > [<000000004afc4310>] system_call_exception+0x114/0x1e0 > [<00000000fb70a873>] system_call_common+0xf0/0x278 > unreferenced object 0xc000201b53e90000 (size 65536): > comm "qemu-kvm", pid 124557, jiffies 4295650285 (age 364.370s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<00000000acc2fb77>] xive_native_alloc_vp_block+0x168/0x210 > xive_native_provision_pages at arch/powerpc/sysdev/xive/native.c:645 > (inlined by) xive_native_alloc_vp_block at arch/powerpc/sysdev/xive/native.c:674 > [<000000004d5c7964>] kvmppc_xive_compute_vp_id+0x20c/0x3b0 [kvm] > [<0000000055317cd2>] kvmppc_xive_connect_vcpu+0xa4/0x4a0 [kvm] > [<0000000093dfc014>] kvm_arch_vcpu_ioctl+0x388/0x508 [kvm] > [<00000000d25aea0f>] kvm_vcpu_ioctl+0x15c/0x950 [kvm] > [<0000000048155cd6>] ksys_ioctl+0xd8/0x130 > [<0000000041ffeaa7>] sys_ioctl+0x28/0x40 > [<000000004afc4310>] system_call_exception+0x114/0x1e0 > [<00000000fb70a873>] system_call_common+0xf0/0x278 > > Signed-off-by: Qian Cai > --- > arch/powerpc/kvm/book3s_64_mmu_radix.c | 16 ++++++++++++++-- > arch/powerpc/sysdev/xive/native.c | 4 ++++ > 2 files changed, 18 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c > index aa12cd4078b3..bc6c1aa3d0e9 100644 > --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c > +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c > @@ -353,7 +353,13 @@ static struct kmem_cache *kvm_pmd_cache; > > static pte_t *kvmppc_pte_alloc(void) > { > - return kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL); > + pte_t *pte; > + > + pte = kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL); > + /* pmd_populate() will only reference _pa(pte). */ > + kmemleak_ignore(pte); > + > + return pte; > } > > static void kvmppc_pte_free(pte_t *ptep) > @@ -363,7 +369,13 @@ static void kvmppc_pte_free(pte_t *ptep) > > static pmd_t *kvmppc_pmd_alloc(void) > { > - return kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL); > + pmd_t *pmd; > + > + pmd = kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL); > + /* pud_populate() will only reference _pa(pmd). */ > + kmemleak_ignore(pmd); > + > + return pmd; > } > > static void kvmppc_pmd_free(pmd_t *pmdp) > diff --git a/arch/powerpc/sysdev/xive/native.c b/arch/powerpc/sysdev/xive/native.c > index 5218fdc4b29a..2d19f28967a6 100644 > --- a/arch/powerpc/sysdev/xive/native.c > +++ b/arch/powerpc/sysdev/xive/native.c > @@ -18,6 +18,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -647,6 +648,9 @@ static bool xive_native_provision_pages(void) > pr_err("Failed to allocate provisioning page\n"); > return false; > } > + /* Kmemleak is unable to track the physical address. */ > + kmemleak_ignore(p); > + > opal_xive_donate_page(chip, __pa(p)); > } > return true; > -- > 2.21.0 (Apple Git-122.2)