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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLACK,USER_AGENT_GIT 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 B1124C2BA19 for ; Sat, 11 Apr 2020 23:06:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 86D69214D8 for ; Sat, 11 Apr 2020 23:06:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586646407; bh=utJayNYThibBc2EP1ygCW7H1/tgMWGD8ZFeUNZo3nNw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=q4cAmP7Ivjd13kiCfl3VbG/W8P+Dnj3NptRjJM9e7YiAufpQYLLhpcoph0ZQ+4Rwi OejnqMO86lX7tlhBZwrvH+RESNqr5jN8k9nJAAEMurli7nKQkypSwqsj/7HO9lYJqC FpUZEOK6HAB5bKrYjky41A4Ah2BXGomTVF48CMTk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728500AbgDKXGo (ORCPT ); Sat, 11 Apr 2020 19:06:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:42198 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728486AbgDKXGn (ORCPT ); Sat, 11 Apr 2020 19:06:43 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DA7B521744; Sat, 11 Apr 2020 23:06:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586646402; bh=utJayNYThibBc2EP1ygCW7H1/tgMWGD8ZFeUNZo3nNw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e7RbWiyK2Gk5cvHThDxY3cuXGLzLQQOzrZ0n1P4BpZsQb4JmW1QXOAxtZK7pXZ8pR +MQ43bWuxCuJalPqxqRr06dYaj4jv39IePwZ3DZ34JqRaDVl+/pJeLyoRgBJ50MVC4 d9hOf7xKn7nmQLYxidh5PaCdWC5zW8lfTunaejXA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alexey Kardashevskiy , Jan Kara , Michael Ellerman , Sasha Levin , linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 5.6 139/149] powerpc/book3s64: Fix error handling in mm_iommu_do_alloc() Date: Sat, 11 Apr 2020 19:03:36 -0400 Message-Id: <20200411230347.22371-139-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200411230347.22371-1-sashal@kernel.org> References: <20200411230347.22371-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexey Kardashevskiy [ Upstream commit c4b78169e3667413184c9a20e11b5832288a109f ] The last jump to free_exit in mm_iommu_do_alloc() happens after page pointers in struct mm_iommu_table_group_mem_t were already converted to physical addresses. Thus calling put_page() on these physical addresses will likely crash. This moves the loop which calculates the pageshift and converts page struct pointers to physical addresses later after the point when we cannot fail; thus eliminating the need to convert pointers back. Fixes: eb9d7a62c386 ("powerpc/mm_iommu: Fix potential deadlock") Reported-by: Jan Kara Signed-off-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191223060351.26359-1-aik@ozlabs.ru Signed-off-by: Sasha Levin --- arch/powerpc/mm/book3s64/iommu_api.c | 39 +++++++++++++++------------- 1 file changed, 21 insertions(+), 18 deletions(-) diff --git a/arch/powerpc/mm/book3s64/iommu_api.c b/arch/powerpc/mm/book3s64/iommu_api.c index eba73ebd8ae57..fa05bbd1f6829 100644 --- a/arch/powerpc/mm/book3s64/iommu_api.c +++ b/arch/powerpc/mm/book3s64/iommu_api.c @@ -121,24 +121,6 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, goto free_exit; } - pageshift = PAGE_SHIFT; - for (i = 0; i < entries; ++i) { - struct page *page = mem->hpages[i]; - - /* - * Allow to use larger than 64k IOMMU pages. Only do that - * if we are backed by hugetlb. - */ - if ((mem->pageshift > PAGE_SHIFT) && PageHuge(page)) - pageshift = page_shift(compound_head(page)); - mem->pageshift = min(mem->pageshift, pageshift); - /* - * We don't need struct page reference any more, switch - * to physical address. - */ - mem->hpas[i] = page_to_pfn(page) << PAGE_SHIFT; - } - good_exit: atomic64_set(&mem->mapped, 1); mem->used = 1; @@ -158,6 +140,27 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, } } + if (mem->dev_hpa == MM_IOMMU_TABLE_INVALID_HPA) { + /* + * Allow to use larger than 64k IOMMU pages. Only do that + * if we are backed by hugetlb. Skip device memory as it is not + * backed with page structs. + */ + pageshift = PAGE_SHIFT; + for (i = 0; i < entries; ++i) { + struct page *page = mem->hpages[i]; + + if ((mem->pageshift > PAGE_SHIFT) && PageHuge(page)) + pageshift = page_shift(compound_head(page)); + mem->pageshift = min(mem->pageshift, pageshift); + /* + * We don't need struct page reference any more, switch + * to physical address. + */ + mem->hpas[i] = page_to_pfn(page) << PAGE_SHIFT; + } + } + list_add_rcu(&mem->next, &mm->context.iommu_group_mem_list); mutex_unlock(&mem_list_mutex); -- 2.20.1