![Linus Torvalds](/assets/img/avatar_default.png)
Pull s390 updates from Martin Schwidefsky: "The major change in this merge is the removal of the support for 31-bit kernels. Naturally 31-bit user space will continue to work via the compat layer. And then some cleanup, some improvements and bug fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (23 commits) s390/smp: wait until secondaries are active & online s390/hibernate: fix save and restore of kernel text section s390/cacheinfo: add missing facility check s390/syscalls: simplify syscall_get_arch() s390/irq: enforce correct irqclass_sub_desc array size s390: remove "64" suffix from mem64.S and swsusp_asm64.S s390/ipl: cleanup macro usage s390/ipl: cleanup shutdown_action attributes s390/ipl: cleanup bin attr usage s390/uprobes: fix address space annotation s390: add missing arch_release_task_struct() declaration s390: make couple of functions and variables static s390/maccess: improve s390_kernel_write() s390/maccess: remove potentially broken probe_kernel_write() s390/watchdog: support for KVM hypervisors and delete pr_info messages s390/watchdog: enable KEEPALIVE for /dev/watchdog s390/dasd: remove setting of scheduler from driver s390/traps: panic() instead of die() on translation exception s390: remove test_facility(2) (== z/Architecture mode active) checks s390/cmpxchg: simplify cmpxchg_double ...
289 lines
7.2 KiB
C
289 lines
7.2 KiB
C
/*
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* flexible mmap layout support
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*
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* Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
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* All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*
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* Started by Ingo Molnar <mingo@elte.hu>
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*/
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#include <linux/personality.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/module.h>
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#include <linux/random.h>
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#include <linux/compat.h>
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#include <linux/security.h>
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#include <asm/pgalloc.h>
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unsigned long mmap_rnd_mask;
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static unsigned long mmap_align_mask;
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static unsigned long stack_maxrandom_size(void)
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{
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if (!(current->flags & PF_RANDOMIZE))
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return 0;
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if (current->personality & ADDR_NO_RANDOMIZE)
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return 0;
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return STACK_RND_MASK << PAGE_SHIFT;
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}
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/*
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* Top of mmap area (just below the process stack).
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*
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* Leave at least a ~32 MB hole.
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*/
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#define MIN_GAP (32*1024*1024)
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#define MAX_GAP (STACK_TOP/6*5)
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static inline int mmap_is_legacy(void)
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{
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if (current->personality & ADDR_COMPAT_LAYOUT)
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return 1;
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if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
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return 1;
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return sysctl_legacy_va_layout;
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}
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unsigned long arch_mmap_rnd(void)
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{
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if (is_32bit_task())
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return (get_random_int() & 0x7ff) << PAGE_SHIFT;
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else
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return (get_random_int() & mmap_rnd_mask) << PAGE_SHIFT;
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}
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static unsigned long mmap_base_legacy(unsigned long rnd)
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{
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return TASK_UNMAPPED_BASE + rnd;
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}
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static inline unsigned long mmap_base(unsigned long rnd)
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{
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unsigned long gap = rlimit(RLIMIT_STACK);
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if (gap < MIN_GAP)
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gap = MIN_GAP;
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else if (gap > MAX_GAP)
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gap = MAX_GAP;
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gap &= PAGE_MASK;
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return STACK_TOP - stack_maxrandom_size() - rnd - gap;
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}
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unsigned long
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arch_get_unmapped_area(struct file *filp, unsigned long addr,
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unsigned long len, unsigned long pgoff, unsigned long flags)
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{
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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struct vm_unmapped_area_info info;
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int do_color_align;
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if (len > TASK_SIZE - mmap_min_addr)
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return -ENOMEM;
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if (flags & MAP_FIXED)
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return addr;
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if (addr) {
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addr = PAGE_ALIGN(addr);
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vma = find_vma(mm, addr);
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if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
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(!vma || addr + len <= vma->vm_start))
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return addr;
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}
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do_color_align = 0;
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if (filp || (flags & MAP_SHARED))
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do_color_align = !is_32bit_task();
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info.flags = 0;
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info.length = len;
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info.low_limit = mm->mmap_base;
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info.high_limit = TASK_SIZE;
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info.align_mask = do_color_align ? (mmap_align_mask << PAGE_SHIFT) : 0;
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info.align_offset = pgoff << PAGE_SHIFT;
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return vm_unmapped_area(&info);
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}
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unsigned long
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arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
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const unsigned long len, const unsigned long pgoff,
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const unsigned long flags)
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{
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struct vm_area_struct *vma;
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struct mm_struct *mm = current->mm;
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unsigned long addr = addr0;
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struct vm_unmapped_area_info info;
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int do_color_align;
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/* requested length too big for entire address space */
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if (len > TASK_SIZE - mmap_min_addr)
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return -ENOMEM;
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if (flags & MAP_FIXED)
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return addr;
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/* requesting a specific address */
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if (addr) {
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addr = PAGE_ALIGN(addr);
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vma = find_vma(mm, addr);
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if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
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(!vma || addr + len <= vma->vm_start))
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return addr;
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}
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do_color_align = 0;
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if (filp || (flags & MAP_SHARED))
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do_color_align = !is_32bit_task();
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info.flags = VM_UNMAPPED_AREA_TOPDOWN;
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info.length = len;
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info.low_limit = max(PAGE_SIZE, mmap_min_addr);
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info.high_limit = mm->mmap_base;
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info.align_mask = do_color_align ? (mmap_align_mask << PAGE_SHIFT) : 0;
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info.align_offset = pgoff << PAGE_SHIFT;
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addr = vm_unmapped_area(&info);
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/*
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* A failed mmap() very likely causes application failure,
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* so fall back to the bottom-up function here. This scenario
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* can happen with large stack limits and large mmap()
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* allocations.
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*/
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if (addr & ~PAGE_MASK) {
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VM_BUG_ON(addr != -ENOMEM);
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info.flags = 0;
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info.low_limit = TASK_UNMAPPED_BASE;
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info.high_limit = TASK_SIZE;
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addr = vm_unmapped_area(&info);
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}
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return addr;
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}
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int s390_mmap_check(unsigned long addr, unsigned long len, unsigned long flags)
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{
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if (is_compat_task() || (TASK_SIZE >= (1UL << 53)))
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return 0;
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if (!(flags & MAP_FIXED))
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addr = 0;
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if ((addr + len) >= TASK_SIZE)
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return crst_table_upgrade(current->mm, 1UL << 53);
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return 0;
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}
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static unsigned long
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s390_get_unmapped_area(struct file *filp, unsigned long addr,
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unsigned long len, unsigned long pgoff, unsigned long flags)
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{
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struct mm_struct *mm = current->mm;
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unsigned long area;
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int rc;
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area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
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if (!(area & ~PAGE_MASK))
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return area;
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if (area == -ENOMEM && !is_compat_task() && TASK_SIZE < (1UL << 53)) {
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/* Upgrade the page table to 4 levels and retry. */
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rc = crst_table_upgrade(mm, 1UL << 53);
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if (rc)
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return (unsigned long) rc;
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area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
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}
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return area;
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}
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static unsigned long
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s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr,
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const unsigned long len, const unsigned long pgoff,
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const unsigned long flags)
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{
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struct mm_struct *mm = current->mm;
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unsigned long area;
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int rc;
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area = arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
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if (!(area & ~PAGE_MASK))
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return area;
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if (area == -ENOMEM && !is_compat_task() && TASK_SIZE < (1UL << 53)) {
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/* Upgrade the page table to 4 levels and retry. */
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rc = crst_table_upgrade(mm, 1UL << 53);
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if (rc)
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return (unsigned long) rc;
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area = arch_get_unmapped_area_topdown(filp, addr, len,
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pgoff, flags);
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}
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return area;
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}
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/*
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* This function, called very early during the creation of a new
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* process VM image, sets up which VM layout function to use:
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*/
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void arch_pick_mmap_layout(struct mm_struct *mm)
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{
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unsigned long random_factor = 0UL;
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if (current->flags & PF_RANDOMIZE)
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random_factor = arch_mmap_rnd();
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/*
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* Fall back to the standard layout if the personality
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* bit is set, or if the expected stack growth is unlimited:
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*/
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if (mmap_is_legacy()) {
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mm->mmap_base = mmap_base_legacy(random_factor);
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mm->get_unmapped_area = s390_get_unmapped_area;
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} else {
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mm->mmap_base = mmap_base(random_factor);
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mm->get_unmapped_area = s390_get_unmapped_area_topdown;
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}
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}
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static int __init setup_mmap_rnd(void)
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{
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struct cpuid cpu_id;
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get_cpu_id(&cpu_id);
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switch (cpu_id.machine) {
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case 0x9672:
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case 0x2064:
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case 0x2066:
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case 0x2084:
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case 0x2086:
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case 0x2094:
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case 0x2096:
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case 0x2097:
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case 0x2098:
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case 0x2817:
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case 0x2818:
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case 0x2827:
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case 0x2828:
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mmap_rnd_mask = 0x7ffUL;
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mmap_align_mask = 0UL;
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break;
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case 0x2964: /* z13 */
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default:
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mmap_rnd_mask = 0x3ff80UL;
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mmap_align_mask = 0x7fUL;
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break;
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}
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return 0;
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}
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early_initcall(setup_mmap_rnd);
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