From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 53D5F606A320 for ; Fri, 23 Oct 2026 16:37:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=ME6dvKPN; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fB5S3V/L 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-Type:MIME-Version: Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=Q6quEbk1wjADIYDnbmI8RxySF7eMLqCwXbNeK/3QTbQ=; b=ME6dvKPNqZLOZsDvTw4cjr1IMi H29sM1e32JSxCvn5oLmZ4RPm83pnX63lSDhVxt+TZJiIYflENGhVKj0hSg8ut2+4Xs6gaSAfDlvzM yWcE5a3vnqiya3CxU/0vzK2HEPVbO1rGnPd/+zPBVNQs1K3UtUd35P0AAdCsDnfHyE/TBv7GX37+W 8C9QaYewThN6B7fJEobW2sCthEgrZAxGj3+GdxPN8shh9LXvLAV74IR0quyRcgQ0le/GNsEz0aqVK 6RGxxstKvq2q1vUqDgB5AHX+Kkd44aba2eQujpfywnzZtBprR3OUFKkHam7iZ87Oy4/3z2DKppUF0 ahnsl3mw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xKIGw-0000000Gff8-2yFc; Fri, 23 Oct 2026 16:37:38 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xKIGv-0000000Gff2-3XnO for kexec@lists.infradead.org; Fri, 23 Oct 2026 16:37:37 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 4674940F63; Fri, 23 Oct 2026 16:37:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 458281F01825; Fri, 23 Oct 2026 16:37:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792773457; bh=Q6quEbk1wjADIYDnbmI8RxySF7eMLqCwXbNeK/3QTbQ=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=fB5S3V/LaS0CaeNTSAaiAwX6QQaGxO+OqMWheFNTKPAvbenke7l17ptFB0A7vQjb2 JHvJGb6q3DIEyS/cw6/UVetwp0iUl8hd5HXKpVWv9ECNJNlcHsBYVnzI6Gd4ZtPYE8 oOlobM1tBmOifszaS3w7PmFzmoUXQeWZBv+GoYyzSU3L9tu8HGfXFF1u4zlQ/X1QFI /pul3GxhWLCswfRS3qeRhzKZZaau5Vpf6R+DkpWAyaT2Q1yXLZsqVJ16O4jIO33YnM N4xKOh5r1qKFveuMPJoE7khOS1YZ7HWmA4gBGV344J3/484dRvoqbOlF1M6el/vCzv Cz6tzE5ePpetw== From: Pratyush Yadav To: Greg Thelen Cc: Mike Rapoport , Pasha Tatashin , Pratyush Yadav , Alexander Graf , Andrew Morton , Evangelos Petrongonas , kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] kho: check fdt_phys in is_kho_boot() In-Reply-To: <20261023054518.3258350-1-gthelen@google.com> (Greg Thelen's message of "Thu, 22 Oct 2026 22:45:18 -0700") References: <20261023054518.3258350-1-gthelen@google.com> Date: Fri, 23 Oct 2026 18:37:33 +0200 Message-ID: <2vxzmrs4fk4y.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Thu, Oct 22 2026, Greg Thelen wrote: > During arm64 setup_arch(), efi_init() -> reserve_regions() calls > is_kho_boot() before arm64_memblock_init() initializes memstart_addr. > At this point memstart_addr still holds its initial sentinel value (-1). > > When booting via kexec with KHO enabled, kho_populate() sets > kho_in.fdt_phys from the /chosen FDT node. Calling is_kho_boot() -> > kho_get_fdt() invokes phys_to_virt(kho_in.fdt_phys), which evaluates > PHYS_OFFSET and triggers VM_BUG_ON(memstart_addr & 1) on arm64 kernels > built with CONFIG_DEBUG_VM=y: > > kernel BUG at ./arch/arm64/include/asm/memory.h:377! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Call trace: > is_kho_boot+0x2c/0x38 (P) > efi_init+0x94/0xf8 > setup_arch+0xf0/0x240 > start_kernel+0x84/0x490 > __primary_switched+0x88/0x98 > > Check kho_in.fdt_phys directly in is_kho_boot() instead of calling > kho_get_fdt() so that early boot callers do not invoke phys_to_virt() > before the linear map offset is initialized. > > Fixes: d6d511639185 ("kexec: introduce is_kho_boot()") > Assisted-by: Gemini:gemini-3.8-flash > Signed-off-by: Greg Thelen Reviewed-by: Pratyush Yadav (Google) [...] -- Regards, Pratyush Yadav