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=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 BA82AC433E0 for ; Wed, 13 Jan 2021 12:18:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6F2F423120 for ; Wed, 13 Jan 2021 12:18:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727439AbhAMMSb (ORCPT ); Wed, 13 Jan 2021 07:18:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:55248 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727011AbhAMMSa (ORCPT ); Wed, 13 Jan 2021 07:18:30 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9ECAC233FC; Wed, 13 Jan 2021 12:17:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1610540248; bh=KctZd2yLeT+pqm+/uA6eByWOmiY4bBxZiglKl0HlLK0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oI8NLhtQb2r8z4+0Mk1iBb1EDDISsoZHeEgLJn4cEKKgDPYYDuRr/HdkXXL2VYgC8 JLpwtHcQ76IxYN7noEj1TLOpsQAXE0Y21U5tCQXTNZdMbLnpFgCPHD3+4GaSWGUD5o JPmySFbRpO+l6gXEoPReKE99E7948uXMUtIxyGIm7QgHheF8S6i2n8nQfY5GDgr0IC 0Dq8tAP883qM5RDCLWWq9OvmRp685VamnsGtPKGK2K+kZz/NI8EXVwbJ1b8ek7R9wH H/iUb+y5+JhelfBG8sumQWUYw90+FM/hti7+eulpS63Jx2Cm7KCO/baWUSc+9kqZsT LQSe3zEnBH59A== From: Leon Romanovsky To: Doug Ledford , Jason Gunthorpe Cc: Aharon Landau , linux-rdma@vger.kernel.org, Maor Gottlieb , Mark Bloch , Parav Pandit Subject: [PATCH rdma-next 1/5] RDMA/umem: Avoid undefined behavior of rounddown_pow_of_two Date: Wed, 13 Jan 2021 14:16:59 +0200 Message-Id: <20210113121703.559778-2-leon@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210113121703.559778-1-leon@kernel.org> References: <20210113121703.559778-1-leon@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: Aharon Landau rounddown_pow_of_two is undefined when the input is 0. Therefore we need to avoid it in ib_umem_find_best_pgsz and return 0. Otherwise, it could result in incorrect page size. Fixes: 3361c29e9279 ("RDMA/umem: Use simpler logic for ib_umem_find_best_pgsz()") Signed-off-by: Aharon Landau Reviewed-by: Jason Gunthorpe Reviewed-by: Maor Gottlieb Signed-off-by: Leon Romanovsky --- drivers/infiniband/core/umem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 95be8cc75d2e..baaf1bf22941 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -137,7 +137,7 @@ unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem, */ if (mask) pgsz_bitmap &= GENMASK(count_trailing_zeros(mask), 0); - return rounddown_pow_of_two(pgsz_bitmap); + return pgsz_bitmap ? rounddown_pow_of_two(pgsz_bitmap) : 0; } EXPORT_SYMBOL(ib_umem_find_best_pgsz); -- 2.29.2