From nobody Wed Dec 17 17:27:43 2025 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 0CD2CC5AD4C for ; Thu, 23 Nov 2023 10:31:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344627AbjKWKbP (ORCPT ); Thu, 23 Nov 2023 05:31:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229477AbjKWKbM (ORCPT ); Thu, 23 Nov 2023 05:31:12 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A74D719D; Thu, 23 Nov 2023 02:31:18 -0800 (PST) Date: Thu, 23 Nov 2023 10:31:15 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1700735476; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lGiLDGmbqrWlSjfhkQgPnYZ8qvWq9oDF9VGMNYqyrrM=; b=zDSlhhUkPXrzP8nf2RHbRQ7QC3w8aKKmUQ2PtJaeIJ3iA3F4zIDPGhGha6b7EovSNZPGNK y5p+K63x+0jqu6e+kbw08RcFqVtCwwHS49EhicvTAZOutuY8FO5iifRbz4YGDt8GOaCZjB z36gGiSaTR3QLylKsth6RDo5V9YS1RUJv1Z8gQ5W0VD5s9qR6ZuhjdXO6ySebxUYJKumCY ao6b//fYnB2dRSFH2hkAIPnd3V3AnQctBbuY6Y/PaleKLABZb9hSEaoR/8XhuHAcsO+jcv WHSovPEmtUHeREE2qwlU7KIjabCvmjDSJk/BAFMh0l2bMJFV0Xosgs+khhjLgQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1700735476; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lGiLDGmbqrWlSjfhkQgPnYZ8qvWq9oDF9VGMNYqyrrM=; b=oiJLfsg/JzQBjq5/beKwYJ+STInXf6rZ9sGhMDJesGJDliSdLwI7T0izhWq7N6ndofhSYj e8Hrnt0HgoxwbVDw== From: "tip-bot2 for Michael Roth" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/mm] x86/mm: Ensure input to pfn_to_kaddr() is treated as a 64-bit type Cc: Dave Hansen , "H. Peter Anvin" , Michael Roth , Ingo Molnar , Andy Lutomirski , Peter Zijlstra , Rik van Riel , Linus Torvalds , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20231122163700.400507-1-michael.roth@amd.com> References: <20231122163700.400507-1-michael.roth@amd.com> MIME-Version: 1.0 Message-ID: <170073547546.398.2637807593174571076.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/mm branch of tip: Commit-ID: 8e5647a723c49d73b9f108a8bb38e8c29d3948ea Gitweb: https://git.kernel.org/tip/8e5647a723c49d73b9f108a8bb38e8c29= d3948ea Author: Michael Roth AuthorDate: Wed, 22 Nov 2023 10:37:00 -06:00 Committer: Ingo Molnar CommitterDate: Thu, 23 Nov 2023 11:13:21 +01:00 x86/mm: Ensure input to pfn_to_kaddr() is treated as a 64-bit type On 64-bit platforms, the pfn_to_kaddr() macro requires that the input value is 64 bits in order to ensure that valid address bits don't get lost when shifting that input by PAGE_SHIFT to calculate the physical address to provide a virtual address for. One such example is in pvalidate_pages() (used by SEV-SNP guests), where the GFN in the struct used for page-state change requests is a 40-bit bit-field, so attempts to pass this GFN field directly into pfn_to_kaddr() ends up causing guest crashes when dealing with addresses above the 1TB range due to the above. Fix this issue with SEV-SNP guests, as well as any similar cases that might cause issues in current/future code, by using an inline function, instead of a macro, so that the input is implicitly cast to the expected 64-bit input type prior to performing the shift operation. While it might be argued that the issue is on the caller side, other archs/macros have taken similar approaches to deal with instances like this, such as ARM explicitly casting the input to phys_addr_t: e48866647b48 ("ARM: 8396/1: use phys_addr_t in pfn_to_kaddr()") A C inline function is even better though. [ mingo: Refined the changelog some more & added __always_inline. ] Fixes: 6c3211796326 ("x86/sev: Add SNP-specific unaccepted memory support") Suggested-by: Dave Hansen Suggested-by: H. Peter Anvin Signed-off-by: Michael Roth Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20231122163700.400507-1-michael.roth@amd.com Cc: Andy Lutomirski Cc: Peter Zijlstra Cc: Rik van Riel Cc: Linus Torvalds --- arch/x86/include/asm/page.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h index d18e5c3..1b93ff8 100644 --- a/arch/x86/include/asm/page.h +++ b/arch/x86/include/asm/page.h @@ -66,10 +66,14 @@ static inline void copy_user_page(void *to, void *from,= unsigned long vaddr, * virt_addr_valid(kaddr) returns true. */ #define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT) -#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) extern bool __virt_addr_valid(unsigned long kaddr); #define virt_addr_valid(kaddr) __virt_addr_valid((unsigned long) (kaddr)) =20 +static __always_inline void *pfn_to_kaddr(unsigned long pfn) +{ + return __va(pfn << PAGE_SHIFT); +} + static __always_inline u64 __canonical_address(u64 vaddr, u8 vaddr_bits) { return ((s64)vaddr << (64 - vaddr_bits)) >> (64 - vaddr_bits);