diff options
Diffstat (limited to 'arch/x86/mm/mmap.c')
| -rw-r--r-- | arch/x86/mm/mmap.c | 45 |
1 files changed, 10 insertions, 35 deletions
diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index db3165714521..82f3a987f7cf 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Flexible mmap layout support * @@ -8,20 +9,6 @@ * All Rights Reserved. * Copyright 2005 Andi Kleen, SUSE Labs. * Copyright 2007 Jiri Kosina, SUSE Labs. - * - * This program 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. - * - * This program 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 */ #include <linux/personality.h> @@ -31,7 +18,9 @@ #include <linux/sched/signal.h> #include <linux/sched/mm.h> #include <linux/compat.h> +#include <linux/elf-randomize.h> #include <asm/elf.h> +#include <asm/io.h> #include "physaddr.h" @@ -91,11 +80,10 @@ unsigned long arch_mmap_rnd(void) } static unsigned long mmap_base(unsigned long rnd, unsigned long task_size, - struct rlimit *rlim_stack) + const struct rlimit *rlim_stack) { unsigned long gap = rlim_stack->rlim_cur; unsigned long pad = stack_maxrandom_size(task_size) + stack_guard_gap; - unsigned long gap_min, gap_max; /* Values close to RLIM_INFINITY can overflow. */ if (gap + pad > gap) @@ -105,13 +93,7 @@ static unsigned long mmap_base(unsigned long rnd, unsigned long task_size, * Top of mmap area (just below the process stack). * Leave an at least ~128 MB hole with possible stack randomization. */ - gap_min = SIZE_128M; - gap_max = (task_size / 6) * 5; - - if (gap < gap_min) - gap = gap_min; - else if (gap > gap_max) - gap = gap_max; + gap = clamp(gap, SIZE_128M, (task_size / 6) * 5); return PAGE_ALIGN(task_size - gap - rnd); } @@ -128,7 +110,7 @@ static unsigned long mmap_legacy_base(unsigned long rnd, */ static void arch_pick_mmap_base(unsigned long *base, unsigned long *legacy_base, unsigned long random_factor, unsigned long task_size, - struct rlimit *rlim_stack) + const struct rlimit *rlim_stack) { *legacy_base = mmap_legacy_base(random_factor, task_size); if (mmap_is_legacy()) @@ -137,12 +119,12 @@ static void arch_pick_mmap_base(unsigned long *base, unsigned long *legacy_base, *base = mmap_base(random_factor, task_size, rlim_stack); } -void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) +void arch_pick_mmap_layout(struct mm_struct *mm, const struct rlimit *rlim_stack) { if (mmap_is_legacy()) - mm->get_unmapped_area = arch_get_unmapped_area; + mm_flags_clear(MMF_TOPDOWN, mm); else - mm->get_unmapped_area = arch_get_unmapped_area_topdown; + mm_flags_set(MMF_TOPDOWN, mm); arch_pick_mmap_base(&mm->mmap_base, &mm->mmap_legacy_base, arch_rnd(mmap64_rnd_bits), task_size_64bit(0), @@ -174,13 +156,6 @@ unsigned long get_mmap_base(int is_legacy) return is_legacy ? mm->mmap_legacy_base : mm->mmap_base; } -const char *arch_vma_name(struct vm_area_struct *vma) -{ - if (vma->vm_flags & VM_MPX) - return "[mpx]"; - return NULL; -} - /** * mmap_address_hint_valid - Validate the address hint of mmap * @addr: Address hint @@ -230,7 +205,7 @@ bool mmap_address_hint_valid(unsigned long addr, unsigned long len) /* Can we access it for direct reading/writing? Must be RAM: */ int valid_phys_addr_range(phys_addr_t addr, size_t count) { - return addr + count <= __pa(high_memory); + return addr + count - 1 <= __pa(high_memory - 1); } /* Can we access it through mmap? Must be a valid physical address: */ |