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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B888C4332F for ; Fri, 14 Oct 2022 14:01:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230267AbiJNOBs (ORCPT ); Fri, 14 Oct 2022 10:01:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36040 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230225AbiJNOBO (ORCPT ); Fri, 14 Oct 2022 10:01:14 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D9DCC7044; Fri, 14 Oct 2022 07:00:49 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 36521CE2664; Fri, 14 Oct 2022 13:55:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AB8C0C433D6; Fri, 14 Oct 2022 13:54:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1665755700; bh=hYbyl7EMfe0bnqNXOD0lVeI25wCK+h+XO7/dvfni/Ao=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W0qCU3imW00BiOheqHPzWFbOwWKDuNBdnYUjnSYacBkoTImtIEi9ZzpScEE/GF8c6 Y9YiBuJlavE3FcpXdJ4FRUhTYn0PmJ2tHCFs/SmUYurbO1dsRKM/Pa4I6eUPxvog8E yyiDQdcwxjkBSu1ATDbtiQ1HWIkP0ugLuFY0isUbr4w9ABpdE5CQd5owVeOFiuKNVr l0QV++34gj66D1NNFWa4H4q2lxiR+9xL3oD6otdF1WtRtbAjYZJ1Y075A4XGbLKw8N pKaeavqG1n62DcYr2qstixctxql3J99pwTO3Sxx4OD/u0sVh379u4hx35lA13guavC Kb3aLB9cTJEGg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Aneesh Kumar K.V" , Michael Ellerman , Sasha Levin , christophe.leroy@csgroup.eu, npiggin@gmail.com, yaozhenguo1@gmail.com, linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 4.14 4/4] powerpc/mm: Fix UBSAN warning reported on hugetlb Date: Fri, 14 Oct 2022 09:54:47 -0400 Message-Id: <20221014135448.2110152-4-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221014135448.2110152-1-sashal@kernel.org> References: <20221014135448.2110152-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Aneesh Kumar K.V" [ Upstream commit 7dd3a7b90bca2c12e2146a47d63cf69a2f5d7e89 ] Powerpc architecture supports 16GB hugetlb pages with hash translation. For 4K page size, this is implemented as a hugepage directory entry at PGD level and for 64K it is implemented as a huge page pte at PUD level With 16GB hugetlb size, offset within a page is greater than 32 bits. Hence switch to use unsigned long type when using hugepd_shift. In order to keep things simpler, we make sure we always use unsigned long type when using hugepd_shift() even though all the hugetlb page size won't require that. The hugetlb_free_p*d_range changes are all related to nohash usage where we can have multiple pgd entries pointing to the same hugepd entries. Hence on book3s64 where we can have > 4GB hugetlb page size we will always find more < next even if we compute the value of more correctly. Hence there is no functional change in this patch except that it fixes the below warning. UBSAN: shift-out-of-bounds in arch/powerpc/mm/hugetlbpage.c:499:21 shift exponent 34 is too large for 32-bit type 'int' CPU: 39 PID: 1673 Comm: a.out Not tainted 6.0.0-rc2-00327-gee88a56e8517-dirty #1 Call Trace: dump_stack_lvl+0x98/0xe0 (unreliable) ubsan_epilogue+0x18/0x70 __ubsan_handle_shift_out_of_bounds+0x1bc/0x390 hugetlb_free_pgd_range+0x5d8/0x600 free_pgtables+0x114/0x290 exit_mmap+0x150/0x550 mmput+0xcc/0x210 do_exit+0x420/0xdd0 do_group_exit+0x4c/0xd0 sys_exit_group+0x24/0x30 system_call_exception+0x250/0x600 system_call_common+0xec/0x250 Signed-off-by: Aneesh Kumar K.V [mpe: Drop generic change to be sent separately, change 1ULL to 1UL] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220908072440.258301-1-aneesh.kumar@linux.ibm.com Signed-off-by: Sasha Levin --- arch/powerpc/mm/hugetlbpage.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index e2d929ddad7f..ae8278dc1e30 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -363,7 +363,7 @@ static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud, * single hugepage, but all of them point to * the same kmem cache that holds the hugepte. */ - more = addr + (1 << hugepd_shift(*(hugepd_t *)pmd)); + more = addr + (1UL << hugepd_shift(*(hugepd_t *)pmd)); if (more > next) next = more; @@ -413,7 +413,7 @@ static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd, * single hugepage, but all of them point to * the same kmem cache that holds the hugepte. */ - more = addr + (1 << hugepd_shift(*(hugepd_t *)pud)); + more = addr + (1UL << hugepd_shift(*(hugepd_t *)pud)); if (more > next) next = more; @@ -480,7 +480,7 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb, * for a single hugepage, but all of them point to the * same kmem cache that holds the hugepte. */ - more = addr + (1 << hugepd_shift(*(hugepd_t *)pgd)); + more = addr + (1UL << hugepd_shift(*(hugepd_t *)pgd)); if (more > next) next = more; -- 2.35.1