CC: kbuild-...@lists.01.org CC: linux-ker...@vger.kernel.org CC: x...@kernel.org TO: Andy Lutomirski <l...@kernel.org> CC: Borislav Petkov <b...@suse.de>
tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/mm head: c46f52231e79af025e2c89e889d69ec20a4c024f commit: c46f52231e79af025e2c89e889d69ec20a4c024f [14/14] x86/{fault,efi}: Fix and rename efi_recover_from_page_fault() :::::: branch date: 13 hours ago :::::: commit date: 13 hours ago config: x86_64-randconfig-m001-20210211 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <l...@intel.com> Reported-by: Dan Carpenter <dan.carpen...@oracle.com> smatch warnings: arch/x86/platform/efi/quirks.c:736 efi_crash_gracefully_on_page_fault() warn: ignoring unreachable code. vim +736 arch/x86/platform/efi/quirks.c 3425d934fc0312 Sai Praneeth 2018-09-11 678 3425d934fc0312 Sai Praneeth 2018-09-11 679 /* 3425d934fc0312 Sai Praneeth 2018-09-11 680 * If any access by any efi runtime service causes a page fault, then, 3425d934fc0312 Sai Praneeth 2018-09-11 681 * 1. If it's efi_reset_system(), reboot through BIOS. 3425d934fc0312 Sai Praneeth 2018-09-11 682 * 2. If any other efi runtime service, then 3425d934fc0312 Sai Praneeth 2018-09-11 683 * a. Return error status to the efi caller process. 3425d934fc0312 Sai Praneeth 2018-09-11 684 * b. Disable EFI Runtime Services forever and 3425d934fc0312 Sai Praneeth 2018-09-11 685 * c. Freeze efi_rts_wq and schedule new process. 3425d934fc0312 Sai Praneeth 2018-09-11 686 * 3425d934fc0312 Sai Praneeth 2018-09-11 687 * @return: Returns, if the page fault is not handled. This function 3425d934fc0312 Sai Praneeth 2018-09-11 688 * will never return if the page fault is handled successfully. 3425d934fc0312 Sai Praneeth 2018-09-11 689 */ c46f52231e79af Andy Lutomirski 2021-02-09 690 void efi_crash_gracefully_on_page_fault(unsigned long phys_addr) 3425d934fc0312 Sai Praneeth 2018-09-11 691 { 3425d934fc0312 Sai Praneeth 2018-09-11 692 if (!IS_ENABLED(CONFIG_X86_64)) 3425d934fc0312 Sai Praneeth 2018-09-11 693 return; 3425d934fc0312 Sai Praneeth 2018-09-11 694 c46f52231e79af Andy Lutomirski 2021-02-09 695 /* c46f52231e79af Andy Lutomirski 2021-02-09 696 * If we get an interrupt/NMI while processing an EFI runtime service c46f52231e79af Andy Lutomirski 2021-02-09 697 * then this is a regular OOPS, not an EFI failure. c46f52231e79af Andy Lutomirski 2021-02-09 698 */ c46f52231e79af Andy Lutomirski 2021-02-09 699 if (in_interrupt()) c46f52231e79af Andy Lutomirski 2021-02-09 700 return; c46f52231e79af Andy Lutomirski 2021-02-09 701 3425d934fc0312 Sai Praneeth 2018-09-11 702 /* 3425d934fc0312 Sai Praneeth 2018-09-11 703 * Make sure that an efi runtime service caused the page fault. c46f52231e79af Andy Lutomirski 2021-02-09 704 * READ_ONCE() because we might be OOPSing in a different thread, c46f52231e79af Andy Lutomirski 2021-02-09 705 * and we don't want to trip KTSAN while trying to OOPS. 3425d934fc0312 Sai Praneeth 2018-09-11 706 */ c46f52231e79af Andy Lutomirski 2021-02-09 707 if (READ_ONCE(efi_rts_work.efi_rts_id) == EFI_NONE || c46f52231e79af Andy Lutomirski 2021-02-09 708 current_work() != &efi_rts_work.work) 3425d934fc0312 Sai Praneeth 2018-09-11 709 return; 3425d934fc0312 Sai Praneeth 2018-09-11 710 3425d934fc0312 Sai Praneeth 2018-09-11 711 /* 3425d934fc0312 Sai Praneeth 2018-09-11 712 * Address range 0x0000 - 0x0fff is always mapped in the efi_pgd, so 3425d934fc0312 Sai Praneeth 2018-09-11 713 * page faulting on these addresses isn't expected. 3425d934fc0312 Sai Praneeth 2018-09-11 714 */ 919aef44d73d5d Qian Cai 2019-06-19 715 if (phys_addr <= 0x0fff) 3425d934fc0312 Sai Praneeth 2018-09-11 716 return; 3425d934fc0312 Sai Praneeth 2018-09-11 717 3425d934fc0312 Sai Praneeth 2018-09-11 718 /* 3425d934fc0312 Sai Praneeth 2018-09-11 719 * Print stack trace as it might be useful to know which EFI Runtime 3425d934fc0312 Sai Praneeth 2018-09-11 720 * Service is buggy. 3425d934fc0312 Sai Praneeth 2018-09-11 721 */ 3425d934fc0312 Sai Praneeth 2018-09-11 722 WARN(1, FW_BUG "Page fault caused by firmware at PA: 0x%lx\n", 3425d934fc0312 Sai Praneeth 2018-09-11 723 phys_addr); 3425d934fc0312 Sai Praneeth 2018-09-11 724 3425d934fc0312 Sai Praneeth 2018-09-11 725 /* 3425d934fc0312 Sai Praneeth 2018-09-11 726 * Buggy efi_reset_system() is handled differently from other EFI 3425d934fc0312 Sai Praneeth 2018-09-11 727 * Runtime Services as it doesn't use efi_rts_wq. Although, 3425d934fc0312 Sai Praneeth 2018-09-11 728 * native_machine_emergency_restart() says that machine_real_restart() 3425d934fc0312 Sai Praneeth 2018-09-11 729 * could fail, it's better not to compilcate this fault handler 3425d934fc0312 Sai Praneeth 2018-09-11 730 * because this case occurs *very* rarely and hence could be improved 3425d934fc0312 Sai Praneeth 2018-09-11 731 * on a need by basis. 3425d934fc0312 Sai Praneeth 2018-09-11 732 */ 5c418dc789a389 Anders Roxell 2019-02-15 733 if (efi_rts_work.efi_rts_id == EFI_RESET_SYSTEM) { 3425d934fc0312 Sai Praneeth 2018-09-11 734 pr_info("efi_reset_system() buggy! Reboot through BIOS\n"); 3425d934fc0312 Sai Praneeth 2018-09-11 735 machine_real_restart(MRR_BIOS); 3425d934fc0312 Sai Praneeth 2018-09-11 @736 return; :::::: The code at line 736 was first introduced by commit :::::: 3425d934fc0312f62024163736a7afe4de20c10f efi/x86: Handle page faults occurring while running EFI runtime services :::::: TO: Sai Praneeth <sai.praneeth.prak...@intel.com> :::::: CC: Ard Biesheuvel <ard.biesheu...@linaro.org> --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org
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