diff options
Diffstat (limited to 'arch/powerpc/mm/mmap.c')
| -rw-r--r-- | arch/powerpc/mm/mmap.c | 228 |
1 files changed, 0 insertions, 228 deletions
diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c deleted file mode 100644 index ae683fdc716c..000000000000 --- a/arch/powerpc/mm/mmap.c +++ /dev/null @@ -1,228 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * flexible mmap layout support - * - * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina. - * All Rights Reserved. - * - * Started by Ingo Molnar <mingo@elte.hu> - */ - -#include <linux/personality.h> -#include <linux/mm.h> -#include <linux/random.h> -#include <linux/sched/signal.h> -#include <linux/sched/mm.h> -#include <linux/elf-randomize.h> -#include <linux/security.h> -#include <linux/mman.h> - -/* - * Top of mmap area (just below the process stack). - * - * Leave at least a ~128 MB hole. - */ -#define MIN_GAP (128*1024*1024) -#define MAX_GAP (TASK_SIZE/6*5) - -static inline int mmap_is_legacy(struct rlimit *rlim_stack) -{ - if (current->personality & ADDR_COMPAT_LAYOUT) - return 1; - - if (rlim_stack->rlim_cur == RLIM_INFINITY) - return 1; - - return sysctl_legacy_va_layout; -} - -unsigned long arch_mmap_rnd(void) -{ - unsigned long shift, rnd; - - shift = mmap_rnd_bits; -#ifdef CONFIG_COMPAT - if (is_32bit_task()) - shift = mmap_rnd_compat_bits; -#endif - rnd = get_random_long() % (1ul << shift); - - return rnd << PAGE_SHIFT; -} - -static inline unsigned long stack_maxrandom_size(void) -{ - if (!(current->flags & PF_RANDOMIZE)) - return 0; - - /* 8MB for 32bit, 1GB for 64bit */ - if (is_32bit_task()) - return (1<<23); - else - return (1<<30); -} - -static inline unsigned long mmap_base(unsigned long rnd, - struct rlimit *rlim_stack) -{ - unsigned long gap = rlim_stack->rlim_cur; - unsigned long pad = stack_maxrandom_size() + stack_guard_gap; - - /* Values close to RLIM_INFINITY can overflow. */ - if (gap + pad > gap) - gap += pad; - - if (gap < MIN_GAP) - gap = MIN_GAP; - else if (gap > MAX_GAP) - gap = MAX_GAP; - - return PAGE_ALIGN(DEFAULT_MAP_WINDOW - gap - rnd); -} - -#ifdef CONFIG_PPC_RADIX_MMU -/* - * Same function as generic code used only for radix, because we don't need to overload - * the generic one. But we will have to duplicate, because hash select - * HAVE_ARCH_UNMAPPED_AREA - */ -static unsigned long -radix__arch_get_unmapped_area(struct file *filp, unsigned long addr, - unsigned long len, unsigned long pgoff, - unsigned long flags) -{ - struct mm_struct *mm = current->mm; - struct vm_area_struct *vma; - int fixed = (flags & MAP_FIXED); - unsigned long high_limit; - struct vm_unmapped_area_info info; - - high_limit = DEFAULT_MAP_WINDOW; - if (addr >= high_limit || (fixed && (addr + len > high_limit))) - high_limit = TASK_SIZE; - - if (len > high_limit) - return -ENOMEM; - - if (fixed) { - if (addr > high_limit - len) - return -ENOMEM; - return addr; - } - - if (addr) { - addr = PAGE_ALIGN(addr); - vma = find_vma(mm, addr); - if (high_limit - len >= addr && addr >= mmap_min_addr && - (!vma || addr + len <= vm_start_gap(vma))) - return addr; - } - - info.flags = 0; - info.length = len; - info.low_limit = mm->mmap_base; - info.high_limit = high_limit; - info.align_mask = 0; - - return vm_unmapped_area(&info); -} - -static unsigned long -radix__arch_get_unmapped_area_topdown(struct file *filp, - const unsigned long addr0, - const unsigned long len, - const unsigned long pgoff, - const unsigned long flags) -{ - struct vm_area_struct *vma; - struct mm_struct *mm = current->mm; - unsigned long addr = addr0; - int fixed = (flags & MAP_FIXED); - unsigned long high_limit; - struct vm_unmapped_area_info info; - - high_limit = DEFAULT_MAP_WINDOW; - if (addr >= high_limit || (fixed && (addr + len > high_limit))) - high_limit = TASK_SIZE; - - if (len > high_limit) - return -ENOMEM; - - if (fixed) { - if (addr > high_limit - len) - return -ENOMEM; - return addr; - } - - if (addr) { - addr = PAGE_ALIGN(addr); - vma = find_vma(mm, addr); - if (high_limit - len >= addr && addr >= mmap_min_addr && - (!vma || addr + len <= vm_start_gap(vma))) - return addr; - } - - info.flags = VM_UNMAPPED_AREA_TOPDOWN; - info.length = len; - info.low_limit = max(PAGE_SIZE, mmap_min_addr); - info.high_limit = mm->mmap_base + (high_limit - DEFAULT_MAP_WINDOW); - info.align_mask = 0; - - addr = vm_unmapped_area(&info); - if (!(addr & ~PAGE_MASK)) - return addr; - VM_BUG_ON(addr != -ENOMEM); - - /* - * A failed mmap() very likely causes application failure, - * so fall back to the bottom-up function here. This scenario - * can happen with large stack limits and large mmap() - * allocations. - */ - return radix__arch_get_unmapped_area(filp, addr0, len, pgoff, flags); -} - -static void radix__arch_pick_mmap_layout(struct mm_struct *mm, - unsigned long random_factor, - struct rlimit *rlim_stack) -{ - if (mmap_is_legacy(rlim_stack)) { - mm->mmap_base = TASK_UNMAPPED_BASE; - mm->get_unmapped_area = radix__arch_get_unmapped_area; - } else { - mm->mmap_base = mmap_base(random_factor, rlim_stack); - mm->get_unmapped_area = radix__arch_get_unmapped_area_topdown; - } -} -#else -/* dummy */ -extern void radix__arch_pick_mmap_layout(struct mm_struct *mm, - unsigned long random_factor, - struct rlimit *rlim_stack); -#endif -/* - * This function, called very early during the creation of a new - * process VM image, sets up which VM layout function to use: - */ -void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) -{ - unsigned long random_factor = 0UL; - - if (current->flags & PF_RANDOMIZE) - random_factor = arch_mmap_rnd(); - - if (radix_enabled()) - return radix__arch_pick_mmap_layout(mm, random_factor, - rlim_stack); - /* - * Fall back to the standard layout if the personality - * bit is set, or if the expected stack growth is unlimited: - */ - if (mmap_is_legacy(rlim_stack)) { - mm->mmap_base = TASK_UNMAPPED_BASE; - mm->get_unmapped_area = arch_get_unmapped_area; - } else { - mm->mmap_base = mmap_base(random_factor, rlim_stack); - mm->get_unmapped_area = arch_get_unmapped_area_topdown; - } -} |