From nobody Sun May 5 03:34:55 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org ARC-Seal: i=1; a=rsa-sha256; t=1622045522; cv=none; d=zohomail.com; s=zohoarc; b=lA1c+TT/PD045oKswM6S70f3CzQNhs4FSTIGtZWlGUKhBPeV//Bhb0H0l7ecUK3QEYWviBJfZHmp74ER0zs8QBlvd/BqDJ/qQEYJohB4wnrcVH5yf4yx7PowQL5/qbpgNkSe4qOE2NpGznNWLw6QauToVCkB320lvJJER0pnvs4= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1622045522; h=Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:Message-ID:Sender:Subject:To; bh=yrQbQMaqTvUXp0yu7HpETMtIwdzmnlOinZ/SB1SX3yg=; b=JPu56EHEk90D4d+F6P/BWG1hYICfgIgIIsMeLOCfoT1/YitqC98qc1FvRvXim9vb5butrRpg5C5MTUPgkvL2s0oOcoCdWaHJJh18FgQtnOXugf3jx5CdUqPUQ5Dkh/JCC5YkAQMg/hFdYkwsC+prEMRX32xjSgCWJMr0KOvXI4Y= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 162204552227737.17214491795016; Wed, 26 May 2021 09:12:02 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.132624.247309 (Exim 4.92) (envelope-from ) id 1llw8A-00056E-9f; Wed, 26 May 2021 16:11:38 +0000 Received: by outflank-mailman (output) from mailman id 132624.247309; Wed, 26 May 2021 16:11:38 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1llw8A-000567-6g; Wed, 26 May 2021 16:11:38 +0000 Received: by outflank-mailman (input) for mailman id 132624; Wed, 26 May 2021 16:11:36 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1llw88-000561-Ra for xen-devel@lists.xenproject.org; Wed, 26 May 2021 16:11:36 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1llw87-0004fU-6J; Wed, 26 May 2021 16:11:35 +0000 Received: from 54-240-197-235.amazon.com ([54.240.197.235] helo=ufe34d9ed68d054.ant.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1llw86-0003AK-T2; Wed, 26 May 2021 16:11:35 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Message-Id:Date:Subject:Cc:To:From; bh=yrQbQMaqTvUXp0yu7HpETMtIwdzmnlOinZ/SB1SX3yg=; b=ioFK1A6SBdCuJWICOD5twMwhhV X4lO53Nvhdb3lw4MXFVRySyx484FDltxvE1TakZPLAgE35lz9h6EQpuqN1BCFKYOjeC3fMZ9PPCrp 2oaKnK3OsxXgVe1TCdcB+ZHgayP295zbTBX2zVFFOKsQkjbtmQMFaDs71VGysWg1UQEw=; From: Julien Grall To: xen-devel@lists.xenproject.org Cc: julien@xen.org, Julien Grall , Andrew Cooper , George Dunlap , Ian Jackson , Jan Beulich , Stefano Stabellini , Wei Liu Subject: [PATCH v2] xen/page_alloc: Remove dead code in alloc_domheap_pages() Date: Wed, 26 May 2021 17:11:29 +0100 Message-Id: <20210526161129.28572-1-julien@xen.org> X-Mailer: git-send-email 2.17.1 X-ZohoMail-DKIM: pass (identity @xen.org) Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Julien Grall Since commit 1aac966e24e9 "xen: support RAM at addresses 0 and 4096", bits_to_zone() will never return 0 and it is expected that we have minimum 2 zones. Therefore the check in alloc_domheap_pages() is unnecessary and can be removed. However, for sanity, it is replaced with an ASSERT(). Also take the opportunity to switch from min_t() to min() as bits_to_zone() cannot return a negative value. The macro is tweaked to make it clearer. This bug was discovered and resolved using Coverity Static Analysis Security Testing (SAST) by Synopsys, Inc. Signed-off-by: Julien Grall Reviewed-by: Jan Beulich --- Changes in v2: - Remove BUILD_BUG_ON() - Switch from min_t() to min() --- xen/common/page_alloc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c index ace6333c18ea..958ba0cd9256 100644 --- a/xen/common/page_alloc.c +++ b/xen/common/page_alloc.c @@ -441,7 +441,7 @@ mfn_t __init alloc_boot_pages(unsigned long nr_pfns, un= signed long pfn_align) #define MEMZONE_XEN 0 #define NR_ZONES (PADDR_BITS - PAGE_SHIFT + 1) =20 -#define bits_to_zone(b) (((b) < (PAGE_SHIFT + 1)) ? 1 : ((b) - PAGE_SHIFT)) +#define bits_to_zone(b) (((b) < (PAGE_SHIFT + 1)) ? 1U : ((b) - PAGE_SHIFT= )) #define page_to_zone(pg) (is_xen_heap_page(pg) ? MEMZONE_XEN : \ (flsl(mfn_x(page_to_mfn(pg))) ? : 1)) =20 @@ -2336,8 +2336,9 @@ struct page_info *alloc_domheap_pages( =20 bits =3D domain_clamp_alloc_bitsize(memflags & MEMF_no_owner ? NULL : = d, bits ? : (BITS_PER_LONG+PAGE_SHIFT)); - if ( (zone_hi =3D min_t(unsigned int, bits_to_zone(bits), zone_hi)) = =3D=3D 0 ) - return NULL; + + zone_hi =3D min(bits_to_zone(bits), zone_hi); + ASSERT(zone_hi !=3D 0); =20 if ( memflags & MEMF_no_owner ) memflags |=3D MEMF_no_refcount; --=20 2.17.1