From patchwork Wed Oct 23 05:36:37 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 2000815 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=GNojavQH; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.infradead.org (client-ip=2607:7c80:54:3::133; helo=bombadil.infradead.org; envelope-from=linux-um-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org; receiver=patchwork.ozlabs.org) Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4XYHwf3Xjlz1xwr for ; Wed, 23 Oct 2024 16:41:38 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=pMVglSrzfw659uFTl63Kmjtp2oxz/obCT3ExoMvUsd0=; b=GNojavQHAXyOADMtZ9YGtbyr3B OVHWYotzXS4Tim5LLbIQiYyLm7TyVoMOFQuOt8yvjXZR+rvFklW6Y+iFFgHqVXfDnQcPGHM0/tcD0 fjqV78dLQDb//VDCnokxgFVGwArGSIvtnHFeKKkNMjQjZM8y6R6Rbkkltvklk/YQGwxVPfnzROGH2 qPTXv9lCX8LNvnOEki7E/L98LGuwRPCIXbdjz9YfcFiIEM1OXSovhsvGH9mXH7c3ydI/BO5T0JLd5 7gNjtkdHCOHbmU5M2xwaS3u3GHRrri8HtV9CK5VYFpknwaFzYB8OcYIE2zdZIUVKbdhKlMIzKti+U Gv1B+2Nw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t3U7k-0000000D5Fv-27HL; Wed, 23 Oct 2024 05:41:36 +0000 Received: from 2a02-8389-2341-5b80-8c6c-e123-fc47-94a5.cable.dynamic.v6.surfer.at ([2a02:8389:2341:5b80:8c6c:e123:fc47:94a5] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1t3U3A-0000000D4L4-25Zx; Wed, 23 Oct 2024 05:36:53 +0000 From: Christoph Hellwig To: Arnd Bergmann Cc: linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-openrisc@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-arch@vger.kernel.org Subject: [PATCH 2/2] asm-generic: add an optional pfn_valid check to page_to_phys Date: Wed, 23 Oct 2024 07:36:37 +0200 Message-ID: <20241023053644.311692-3-hch@lst.de> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20241023053644.311692-1-hch@lst.de> References: <20241023053644.311692-1-hch@lst.de> MIME-Version: 1.0 X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org page_to_pfn is usually implemented by pointer arithmetics on the memory map, which means that bogus input can lead to even more bogus output. Powerpc had a pfn_valid check on the intermediate pfn in the page_to_phys implementation when CONFIG_DEBUG_VIRTUAL is defined, which seems generally useful, so add that to the generic version. Signed-off-by: Christoph Hellwig --- include/asm-generic/memory_model.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/include/asm-generic/memory_model.h b/include/asm-generic/memory_model.h index a73a140cbecd..6d1fb6162ac1 100644 --- a/include/asm-generic/memory_model.h +++ b/include/asm-generic/memory_model.h @@ -64,7 +64,17 @@ static inline int pfn_valid(unsigned long pfn) #define page_to_pfn __page_to_pfn #define pfn_to_page __pfn_to_page +#ifdef CONFIG_DEBUG_VIRTUAL +#define page_to_phys(page) \ +({ \ + unsigned long __pfn = page_to_pfn(page); \ + \ + WARN_ON_ONCE(!pfn_valid(__pfn)); \ + PFN_PHYS(__pfn); \ +}) +#else #define page_to_phys(page) PFN_PHYS(page_to_pfn(page)) +#endif /* CONFIG_DEBUG_VIRTUAL */ #define phys_to_page(phys) pfn_to_page(PHYS_PFN(phys)) #endif /* __ASSEMBLY__ */