From nobody Fri Apr 19 11:04:16 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=1617736992; cv=none; d=zohomail.com; s=zohoarc; b=XQwynne5UBubr0OMcJTYIyZ2gL4AHuBqH2gmSFIx1u/HgsS4qA24GTw2heRLi7pLxD0yoOodhT7anG+iId4HpxsmQdgkEY8rigjni7Aw8RrhF8bPUNYc7wSany8XzbaIo0QXACe67UJX+xSTQhPMtV7gvrjjbUZPz28wuqdqWW8= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1617736992; h=Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:Message-ID:Sender:Subject:To; bh=PrkuCfGhHLJrZ4S+yOEu6s9dgnK1NNTZT78cqa6PGl8=; b=KJ6QJ12hBfBuMFqwUNtISryqlJ5OexqfFbgphn1ZQDpVucFHuBDMVF8qGCS4pQCOEulaPMyK41IA+j3BxYD+x9LJ8BpTbhTagCG8MdWSv1zG8Z2wckSh8Qd1V5shuETKJXtIAHXVAru6k7FJMe7aSY6Fo5MxzwgP5pDKMMm72vo= 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 1617736992820856.185178669804; Tue, 6 Apr 2021 12:23:12 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.106269.203261 (Exim 4.92) (envelope-from ) id 1lTrHp-0004Fe-2F; Tue, 06 Apr 2021 19:22:53 +0000 Received: by outflank-mailman (output) from mailman id 106269.203261; Tue, 06 Apr 2021 19:22:53 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lTrHo-0004FX-VV; Tue, 06 Apr 2021 19:22:52 +0000 Received: by outflank-mailman (input) for mailman id 106269; Tue, 06 Apr 2021 19:22:50 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lTrHm-0004FS-SV for xen-devel@lists.xenproject.org; Tue, 06 Apr 2021 19:22:50 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lTrHl-0005d3-P7; Tue, 06 Apr 2021 19:22:49 +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 1lTrHl-0000zd-9m; Tue, 06 Apr 2021 19:22:49 +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=PrkuCfGhHLJrZ4S+yOEu6s9dgnK1NNTZT78cqa6PGl8=; b=YvMSibRja/Vs2ECLsL57FpEjVl dJUh3M+WZZx8cSxrzl376E8sX3VXWiKPaFR4X8pYdvK0O0B1n4Irhef2cuBFaeIp+xpqM7i5ONEMj 5NZ0j0/k0U6R1mzLtJ2ObHG3/iMz8DHsup96H8Nq1HwIDjzU2cNvNbKP/OIXq4VoD2oA=; 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] xen/page_alloc: Remove dead code in alloc_domheap_pages() Date: Tue, 6 Apr 2021 20:22:46 +0100 Message-Id: <20210406192246.15657-1-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 check atbuild time that NR_ZONES is minimum 2. 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 --- xen/common/page_alloc.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c index 1744e6faa5c4..68e47d963842 100644 --- a/xen/common/page_alloc.c +++ b/xen/common/page_alloc.c @@ -457,6 +457,12 @@ static long total_avail_pages; static DEFINE_SPINLOCK(heap_lock); static long outstanding_claims; /* total outstanding claims by all domains= */ =20 +static void __init __maybe_unused build_assertions(void) +{ + /* Zone 0 is reserved for Xen, so we at least need two zones to functi= on.*/ + BUILD_BUG_ON(NR_ZONES < 2); +} + unsigned long domain_adjust_tot_pages(struct domain *d, long pages) { long dom_before, dom_after, dom_claimed, sys_before, sys_after; @@ -2340,8 +2346,9 @@ 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_t(unsigned int, 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