From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:50604 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756481AbdDRMut (ORCPT ); Tue, 18 Apr 2017 08:50:49 -0400 Subject: Patch "x86/efi: Don't try to reserve runtime regions" has been added to the 4.9-stable tree To: osandov@fb.com, ard.biesheuvel@linaro.org, dyoung@redhat.com, gregkh@linuxfoundation.org, matt@codeblueprint.co.uk, mingo@kernel.org, peterz@infradead.org, pjones@redhat.com, tglx@linutronix.de, torvalds@linux-foundation.org Cc: , From: Date: Tue, 18 Apr 2017 14:50:28 +0200 Message-ID: <1492519828147123@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86/efi: Don't try to reserve runtime regions to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-efi-don-t-try-to-reserve-runtime-regions.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 6f6266a561306e206e0e31a5038f029b6a7b1d89 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 12 Apr 2017 16:27:19 +0100 Subject: x86/efi: Don't try to reserve runtime regions From: Omar Sandoval commit 6f6266a561306e206e0e31a5038f029b6a7b1d89 upstream. Reserving a runtime region results in splitting the EFI memory descriptors for the runtime region. This results in runtime region descriptors with bogus memory mappings, leading to interesting crashes like the following during a kexec: general protection fault: 0000 [#1] SMP Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc1 #53 Hardware name: Wiwynn Leopard-Orv2/Leopard-DDR BW, BIOS LBM05 09/30/2016 RIP: 0010:virt_efi_set_variable() ... Call Trace: efi_delete_dummy_variable() efi_enter_virtual_mode() start_kernel() ? set_init_arg() x86_64_start_reservations() x86_64_start_kernel() start_cpu() ... Kernel panic - not syncing: Fatal exception Runtime regions will not be freed and do not need to be reserved, so skip the memmap modification in this case. Signed-off-by: Omar Sandoval Signed-off-by: Matt Fleming Cc: Ard Biesheuvel Cc: Dave Young Cc: Linus Torvalds Cc: Peter Jones Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Fixes: 8e80632fb23f ("efi/esrt: Use efi_mem_reserve() and avoid a kmalloc()") Link: http://lkml.kernel.org/r/20170412152719.9779-2-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/platform/efi/quirks.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/arch/x86/platform/efi/quirks.c +++ b/arch/x86/platform/efi/quirks.c @@ -201,6 +201,10 @@ void __init efi_arch_mem_reserve(phys_ad return; } + /* No need to reserve regions that will never be freed. */ + if (md.attribute & EFI_MEMORY_RUNTIME) + return; + size += addr % EFI_PAGE_SIZE; size = round_up(size, EFI_PAGE_SIZE); addr = round_down(addr, EFI_PAGE_SIZE); Patches currently in stable-queue which might be from osandov@fb.com are queue-4.9/x86-efi-don-t-try-to-reserve-runtime-regions.patch