/* mpih-rshift.c - MPI helper functions * Copyright (C) 1994, 1996, 1998, 1999, * 2000, 2001 Free Software Foundation, Inc. * * This file is part of GNUPG * * GNUPG is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * GNUPG is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA * * Note: This code is heavily based on the GNU MP Library. * Actually it's the same code with only minor changes in the * way the data is stored; this is to support the abstraction * of an optional secure memory allocation which may be used * to avoid revealing of sensitive data due to paging etc. * The GNU MP Library itself is published under the LGPL; * however I decided to publish this code under the plain GPL. */ #include "mpi-internal.h" /* Shift U (pointed to by UP and USIZE limbs long) CNT bits to the right * and store the USIZE least significant limbs of the result at WP. * The bits shifted out to the right are returned. * * Argument constraints: * 1. 0 < CNT < BITS_PER_MP_LIMB * 2. If the result is to be written over the input, WP must be <= UP. */ mpi_limb_t mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, unsigned cnt) { mpi_limb_t high_limb, low_limb; unsigned sh_1, sh_2; mpi_size_t i; mpi_limb_t retval; sh_1 = cnt; wp -= 1; sh_2 = BITS_PER_MPI_LIMB - sh_1; high_limb = up[0]; retval = high_limb << sh_2; low_limb = high_limb; for (i = 1; i < usize; i++) { high_limb = up[i]; wp[i] = (low_limb >> sh_1) | (high_limb << sh_2); low_limb = high_limb; } wp[i] = low_limb >> sh_1; return retval; }
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authorJiri Kosina <jkosina@suse.cz>2017-01-27 22:25:52 +0000
committerIngo Molnar <mingo@kernel.org>2017-01-28 09:18:56 +0100
commitbf29bddf0417a4783da3b24e8c9e017ac649326f (patch)
tree54a05a4883b73f80e4e1d8c4b15750aa01c39932 /net/sunrpc
parent883af14e67e8b8702b5560aa64c888c0cd0bd66c (diff)
x86/efi: Always map the first physical page into the EFI pagetables
Commit: 129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode") stopped creating 1:1 mappings for all RAM, when running in native 64-bit mode. It turns out though that there are 64-bit EFI implementations in the wild (this particular problem has been reported on a Lenovo Yoga 710-11IKB), which still make use of the first physical page for their own private use, even though they explicitly mark it EFI_CONVENTIONAL_MEMORY in the memory map. In case there is no mapping for this particular frame in the EFI pagetables, as soon as firmware tries to make use of it, a triple fault occurs and the system reboots (in case of the Yoga 710-11IKB this is very early during bootup). Fix that by always mapping the first page of physical memory into the EFI pagetables. We're free to hand this page to the BIOS, as trim_bios_range() will reserve the first page and isolate it away from memory allocators anyway. Note that just reverting 129766708 alone is not enough on v4.9-rc1+ to fix the regression on affected hardware, as this commit: ab72a27da ("x86/efi: Consolidate region mapping logic") later made the first physical frame not to be mapped anyway. Reported-by: Hanka Pavlikova <hanka@ucw.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Laura Abbott <labbott@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vojtech Pavlik <vojtech@ucw.cz> Cc: Waiman Long <waiman.long@hpe.com> Cc: linux-efi@vger.kernel.org Cc: stable@kernel.org # v4.8+ Fixes: 129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode") Link: http://lkml.kernel.org/r/20170127222552.22336-1-matt@codeblueprint.co.uk [ Tidied up the changelog and the comment. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'net/sunrpc')