From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752569AbaKKXUF (ORCPT ); Tue, 11 Nov 2014 18:20:05 -0500 Received: from mga01.intel.com ([192.55.52.88]:33664 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752489AbaKKXUD (ORCPT ); Tue, 11 Nov 2014 18:20:03 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,362,1413270000"; d="scan'208";a="620835743" Message-ID: <5462999A.7090706@intel.com> Date: Tue, 11 Nov 2014 15:19:54 -0800 From: Dave Hansen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Borislav Petkov , Matt Fleming , the arch/x86 maintainers , LKML Subject: BUG() at boot in __phys_addr with DEBUG_VIRTUAL Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I'm seeing a BUG() at boot in __phys_addr when it has DEBUG_VIRTUAL enabled: >> [ 1.193264] ------------[ cut here ]------------ >> [ 1.198502] kernel BUG at /home/davehans/linux.git/arch/x86/mm/physaddr.c:36! > ... >> [ 1.368810] Call Trace: >> [ 1.371590] [] __change_page_attr_set_clr+0x42c/0xff0 >> [ 1.379197] [] kernel_map_pages_in_pgd+0x72/0x110 >> [ 1.386410] [] __map_region+0x45/0x63 >> [ 1.392437] [] efi_map_region+0x32/0xce >> [ 1.398663] [] efi_enter_virtual_mode+0x18c/0x3a4 >> [ 1.405876] [] start_kernel+0x421/0x4a1 >> [ 1.412101] [] ? set_init_arg+0x55/0x55 >> [ 1.418327] [] ? early_idt_handlers+0x120/0x120 >> [ 1.425342] [] x86_64_start_reservations+0x2a/0x2c >> [ 1.432652] [] x86_64_start_kernel+0x152/0x161 >> [ 1.439565] Code: 0f 94 c2 31 c0 e8 a6 47 83 00 48 c7 c7 41 49 cc 81 31 c0 e8 98 47 83 00 31 d2 be 01 00 00 00 48 c7 c7 a0 49 f2 81 e8 ab 4a 0e 00 <0f> 0b 0f 0b 4c 89 e2 48 c7 c6 b3 e5 a0 81 48 c7 c7 5c 7a ca 81 >> [ 1.461866] RIP [] __phys_addr+0x185/0x260 >> [ 1.468400] RSP >> [ 1.472396] ---[ end trace b59b0f17341a4bc4 ]--- >> [ 1.477663] Kernel panic - not syncing: Attempted to kill the idle task! >> [ 1.485270] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! But I've noticed something odd. kernel_map_pages_in_pgd() takes a pfn: extern int kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, unsigned numpages, unsigned long page_flags); But the code in arch/x86/platform/efi/efi_64.c seems a bit confused about that. Two users pass a physical address while a third passes in a pfn: > if (kernel_map_pages_in_pgd(pgd, text >> PAGE_SHIFT, text, npages, 0)) { > if (kernel_map_pages_in_pgd(pgd, md->phys_addr, va, md->num_pages, pf)) > if (kernel_map_pages_in_pgd(pgd, pa_memmap, pa_memmap, num_pages, _PAGE_NX)) { kernel_map_pages_in_pgd() also sticks that value in to 'struct cpa_data'->pfn. But, then the "PFN" seems to get used like a physical address. For instance: set_pmd(pmd, __pmd(cpa->pfn | _PAGE_PSE | ... How could this possibly work?