arch/s390/mm/mmap.c - kernel/msm-4.19 - Gitiles

 /*
  *  flexible mmap layout support
  *
  * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
  * All Rights Reserved.
  *
  * 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
  *
  *
  * Started by Ingo Molnar <mingo@elte.hu>
  */

 #include <linux/personality.h>
 #include <linux/mm.h>
 #include <linux/mman.h>
 #include <linux/module.h>
 #include <linux/random.h>
 #include <linux/compat.h>
 #include <linux/security.h>
 #include <asm/pgalloc.h>

 unsigned long mmap_rnd_mask;
 unsigned long mmap_align_mask;

 static unsigned long stack_maxrandom_size(void)
 {
 	if (!(current->flags & PF_RANDOMIZE))
 		return 0;
 	if (current->personality & ADDR_NO_RANDOMIZE)
 		return 0;
 	return STACK_RND_MASK << PAGE_SHIFT;
 }

 /*
  * Top of mmap area (just below the process stack).
  *
  * Leave at least a ~32 MB hole.
  */
 #define MIN_GAP (32*1024*1024)
 #define MAX_GAP (STACK_TOP/6*5)

 static inline int mmap_is_legacy(void)
 {
 	if (current->personality & ADDR_COMPAT_LAYOUT)
 		return 1;
 	if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
 		return 1;
 	return sysctl_legacy_va_layout;
 }

 static unsigned long mmap_rnd(void)
 {
 	if (is_32bit_task())
 		return (get_random_int() & 0x7ff) << PAGE_SHIFT;
 	else
 		return (get_random_int() & mmap_rnd_mask) << PAGE_SHIFT;
 }

 static unsigned long mmap_base_legacy(unsigned long rnd)
 {
 	return TASK_UNMAPPED_BASE + rnd;
 }

 static inline unsigned long mmap_base(unsigned long rnd)
 {
 	unsigned long gap = rlimit(RLIMIT_STACK);

 	if (gap < MIN_GAP)
 		gap = MIN_GAP;
 	else if (gap > MAX_GAP)
 		gap = MAX_GAP;
 	gap &= PAGE_MASK;
 	return STACK_TOP - stack_maxrandom_size() - rnd - gap;
 }

 unsigned long
 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;
 	struct vm_unmapped_area_info info;
 	int do_color_align;

 	if (len > TASK_SIZE - mmap_min_addr)
 		return -ENOMEM;

 	if (flags & MAP_FIXED)
 		return addr;

 	if (addr) {
 		addr = PAGE_ALIGN(addr);
 		vma = find_vma(mm, addr);
 		if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
 		    (!vma || addr + len <= vma->vm_start))
 			return addr;
 	}

 	do_color_align = 0;
 	if (filp || (flags & MAP_SHARED))
 		do_color_align = !is_32bit_task();

 	info.flags = 0;
 	info.length = len;
 	info.low_limit = mm->mmap_base;
 	info.high_limit = TASK_SIZE;
 	info.align_mask = do_color_align ? (mmap_align_mask << PAGE_SHIFT) : 0;
 	info.align_offset = pgoff << PAGE_SHIFT;
 	return vm_unmapped_area(&info);
 }

 unsigned long
 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;
 	struct vm_unmapped_area_info info;
 	int do_color_align;

 	/* requested length too big for entire address space */
 	if (len > TASK_SIZE - mmap_min_addr)
 		return -ENOMEM;

 	if (flags & MAP_FIXED)
 		return addr;

 	/* requesting a specific address */
 	if (addr) {
 		addr = PAGE_ALIGN(addr);
 		vma = find_vma(mm, addr);
 		if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
 				(!vma || addr + len <= vma->vm_start))
 			return addr;
 	}

 	do_color_align = 0;
 	if (filp || (flags & MAP_SHARED))
 		do_color_align = !is_32bit_task();

 	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
 	info.length = len;
 	info.low_limit = max(PAGE_SIZE, mmap_min_addr);
 	info.high_limit = mm->mmap_base;
 	info.align_mask = do_color_align ? (mmap_align_mask << PAGE_SHIFT) : 0;
 	info.align_offset = pgoff << PAGE_SHIFT;
 	addr = vm_unmapped_area(&info);

 	/*
 	 * 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.
 	 */
 	if (addr & ~PAGE_MASK) {
 		VM_BUG_ON(addr != -ENOMEM);
 		info.flags = 0;
 		info.low_limit = TASK_UNMAPPED_BASE;
 		info.high_limit = TASK_SIZE;
 		addr = vm_unmapped_area(&info);
 	}

 	return addr;
 }

 unsigned long randomize_et_dyn(void)
 {
 	unsigned long base;

 	base = STACK_TOP / 3 * 2;
 	if (!is_32bit_task())
 		/* Align to 4GB */
 		base &= ~((1UL << 32) - 1);

 	if (current->flags & PF_RANDOMIZE)
 		base += mmap_rnd();

 	return base;
 }

 #ifndef CONFIG_64BIT

 /*
  * 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)
 {
 	unsigned long random_factor = 0UL;

 	if (current->flags & PF_RANDOMIZE)
 		random_factor = mmap_rnd();

 	/*
 	 * Fall back to the standard layout if the personality
 	 * bit is set, or if the expected stack growth is unlimited:
 	 */
 	if (mmap_is_legacy()) {
 		mm->mmap_base = mmap_base_legacy(random_factor);
 		mm->get_unmapped_area = arch_get_unmapped_area;
 	} else {
 		mm->mmap_base = mmap_base(random_factor);
 		mm->get_unmapped_area = arch_get_unmapped_area_topdown;
 	}
 }

 #else

 int s390_mmap_check(unsigned long addr, unsigned long len, unsigned long flags)
 {
 	if (is_compat_task() || (TASK_SIZE >= (1UL << 53)))
 		return 0;
 	if (!(flags & MAP_FIXED))
 		addr = 0;
 	if ((addr + len) >= TASK_SIZE)
 		return crst_table_upgrade(current->mm, 1UL << 53);
 	return 0;
 }

 static unsigned long
 s390_get_unmapped_area(struct file *filp, unsigned long addr,
 		unsigned long len, unsigned long pgoff, unsigned long flags)
 {
 	struct mm_struct *mm = current->mm;
 	unsigned long area;
 	int rc;

 	area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
 	if (!(area & ~PAGE_MASK))
 		return area;
 	if (area == -ENOMEM && !is_compat_task() && TASK_SIZE < (1UL << 53)) {
 		/* Upgrade the page table to 4 levels and retry. */
 		rc = crst_table_upgrade(mm, 1UL << 53);
 		if (rc)
 			return (unsigned long) rc;
 		area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
 	}
 	return area;
 }

 static unsigned long
 s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr,
 			  const unsigned long len, const unsigned long pgoff,
 			  const unsigned long flags)
 {
 	struct mm_struct *mm = current->mm;
 	unsigned long area;
 	int rc;

 	area = arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
 	if (!(area & ~PAGE_MASK))
 		return area;
 	if (area == -ENOMEM && !is_compat_task() && TASK_SIZE < (1UL << 53)) {
 		/* Upgrade the page table to 4 levels and retry. */
 		rc = crst_table_upgrade(mm, 1UL << 53);
 		if (rc)
 			return (unsigned long) rc;
 		area = arch_get_unmapped_area_topdown(filp, addr, len,
 						      pgoff, flags);
 	}
 	return area;
 }
 /*
  * 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)
 {
 	unsigned long random_factor = 0UL;

 	if (current->flags & PF_RANDOMIZE)
 		random_factor = mmap_rnd();

 	/*
 	 * Fall back to the standard layout if the personality
 	 * bit is set, or if the expected stack growth is unlimited:
 	 */
 	if (mmap_is_legacy()) {
 		mm->mmap_base = mmap_base_legacy(random_factor);
 		mm->get_unmapped_area = s390_get_unmapped_area;
 	} else {
 		mm->mmap_base = mmap_base(random_factor);
 		mm->get_unmapped_area = s390_get_unmapped_area_topdown;
 	}
 }

 static int __init setup_mmap_rnd(void)
 {
 	struct cpuid cpu_id;

 	get_cpu_id(&cpu_id);
 	switch (cpu_id.machine) {
 	case 0x9672:
 	case 0x2064:
 	case 0x2066:
 	case 0x2084:
 	case 0x2086:
 	case 0x2094:
 	case 0x2096:
 	case 0x2097:
 	case 0x2098:
 	case 0x2817:
 	case 0x2818:
 	case 0x2827:
 	case 0x2828:
 		mmap_rnd_mask = 0x7ffUL;
 		mmap_align_mask = 0UL;
 		break;
 	case 0x2964:	/* z13 */
 	default:
 		mmap_rnd_mask = 0x3ff80UL;
 		mmap_align_mask = 0x7fUL;
 		break;
 	}
 	return 0;
 }
 early_initcall(setup_mmap_rnd);

 #endif
	/*
	* flexible mmap layout support
	*
	* Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
	* All Rights Reserved.
	*
	* 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
	*
	*
	* Started by Ingo Molnar <mingo@elte.hu>
	*/

	#include <linux/personality.h>
	#include <linux/mm.h>
	#include <linux/mman.h>
	#include <linux/module.h>
	#include <linux/random.h>
	#include <linux/compat.h>
	#include <linux/security.h>
	#include <asm/pgalloc.h>

	unsigned long mmap_rnd_mask;
	unsigned long mmap_align_mask;

	static unsigned long stack_maxrandom_size(void)
	{
	if (!(current->flags & PF_RANDOMIZE))
	return 0;
	if (current->personality & ADDR_NO_RANDOMIZE)
	return 0;
	return STACK_RND_MASK << PAGE_SHIFT;
	}

	/*
	* Top of mmap area (just below the process stack).
	*
	* Leave at least a ~32 MB hole.
	*/
	#define MIN_GAP (3210241024)
	#define MAX_GAP (STACK_TOP/6*5)

	static inline int mmap_is_legacy(void)
	{
	if (current->personality & ADDR_COMPAT_LAYOUT)
	return 1;
	if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
	return 1;
	return sysctl_legacy_va_layout;
	}

	static unsigned long mmap_rnd(void)
	{
	if (is_32bit_task())
	return (get_random_int() & 0x7ff) << PAGE_SHIFT;
	else
	return (get_random_int() & mmap_rnd_mask) << PAGE_SHIFT;
	}

	static unsigned long mmap_base_legacy(unsigned long rnd)
	{
	return TASK_UNMAPPED_BASE + rnd;
	}

	static inline unsigned long mmap_base(unsigned long rnd)
	{
	unsigned long gap = rlimit(RLIMIT_STACK);

	if (gap < MIN_GAP)
	gap = MIN_GAP;
	else if (gap > MAX_GAP)
	gap = MAX_GAP;
	gap &= PAGE_MASK;
	return STACK_TOP - stack_maxrandom_size() - rnd - gap;
	}

	unsigned long
	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;
	struct vm_unmapped_area_info info;
	int do_color_align;

	if (len > TASK_SIZE - mmap_min_addr)
	return -ENOMEM;

	if (flags & MAP_FIXED)
	return addr;

	if (addr) {
	addr = PAGE_ALIGN(addr);
	vma = find_vma(mm, addr);
	if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
	(!vma \|\| addr + len <= vma->vm_start))
	return addr;
	}

	do_color_align = 0;
	if (filp \|\| (flags & MAP_SHARED))
	do_color_align = !is_32bit_task();

	info.flags = 0;
	info.length = len;
	info.low_limit = mm->mmap_base;
	info.high_limit = TASK_SIZE;
	info.align_mask = do_color_align ? (mmap_align_mask << PAGE_SHIFT) : 0;
	info.align_offset = pgoff << PAGE_SHIFT;
	return vm_unmapped_area(&info);
	}

	unsigned long
	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;
	struct vm_unmapped_area_info info;
	int do_color_align;

	/* requested length too big for entire address space */
	if (len > TASK_SIZE - mmap_min_addr)
	return -ENOMEM;

	if (flags & MAP_FIXED)
	return addr;

	/* requesting a specific address */
	if (addr) {
	addr = PAGE_ALIGN(addr);
	vma = find_vma(mm, addr);
	if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
	(!vma \|\| addr + len <= vma->vm_start))
	return addr;
	}

	do_color_align = 0;
	if (filp \|\| (flags & MAP_SHARED))
	do_color_align = !is_32bit_task();

	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
	info.length = len;
	info.low_limit = max(PAGE_SIZE, mmap_min_addr);
	info.high_limit = mm->mmap_base;
	info.align_mask = do_color_align ? (mmap_align_mask << PAGE_SHIFT) : 0;
	info.align_offset = pgoff << PAGE_SHIFT;
	addr = vm_unmapped_area(&info);

	/*
	* 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.
	*/
	if (addr & ~PAGE_MASK) {
	VM_BUG_ON(addr != -ENOMEM);
	info.flags = 0;
	info.low_limit = TASK_UNMAPPED_BASE;
	info.high_limit = TASK_SIZE;
	addr = vm_unmapped_area(&info);
	}

	return addr;
	}

	unsigned long randomize_et_dyn(void)
	{
	unsigned long base;

	base = STACK_TOP / 3 * 2;
	if (!is_32bit_task())
	/* Align to 4GB */
	base &= ~((1UL << 32) - 1);

	if (current->flags & PF_RANDOMIZE)
	base += mmap_rnd();

	return base;
	}

	#ifndef CONFIG_64BIT

	/*
	* 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)
	{
	unsigned long random_factor = 0UL;

	if (current->flags & PF_RANDOMIZE)
	random_factor = mmap_rnd();

	/*
	* Fall back to the standard layout if the personality
	* bit is set, or if the expected stack growth is unlimited:
	*/
	if (mmap_is_legacy()) {
	mm->mmap_base = mmap_base_legacy(random_factor);
	mm->get_unmapped_area = arch_get_unmapped_area;
	} else {
	mm->mmap_base = mmap_base(random_factor);
	mm->get_unmapped_area = arch_get_unmapped_area_topdown;
	}
	}

	#else

	int s390_mmap_check(unsigned long addr, unsigned long len, unsigned long flags)
	{
	if (is_compat_task() \|\| (TASK_SIZE >= (1UL << 53)))
	return 0;
	if (!(flags & MAP_FIXED))
	addr = 0;
	if ((addr + len) >= TASK_SIZE)
	return crst_table_upgrade(current->mm, 1UL << 53);
	return 0;
	}

	static unsigned long
	s390_get_unmapped_area(struct file *filp, unsigned long addr,
	unsigned long len, unsigned long pgoff, unsigned long flags)
	{
	struct mm_struct *mm = current->mm;
	unsigned long area;
	int rc;

	area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
	if (!(area & ~PAGE_MASK))
	return area;
	if (area == -ENOMEM && !is_compat_task() && TASK_SIZE < (1UL << 53)) {
	/* Upgrade the page table to 4 levels and retry. */
	rc = crst_table_upgrade(mm, 1UL << 53);
	if (rc)
	return (unsigned long) rc;
	area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
	}
	return area;
	}

	static unsigned long
	s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr,
	const unsigned long len, const unsigned long pgoff,
	const unsigned long flags)
	{
	struct mm_struct *mm = current->mm;
	unsigned long area;
	int rc;

	area = arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
	if (!(area & ~PAGE_MASK))
	return area;
	if (area == -ENOMEM && !is_compat_task() && TASK_SIZE < (1UL << 53)) {
	/* Upgrade the page table to 4 levels and retry. */
	rc = crst_table_upgrade(mm, 1UL << 53);
	if (rc)
	return (unsigned long) rc;
	area = arch_get_unmapped_area_topdown(filp, addr, len,
	pgoff, flags);
	}
	return area;
	}
	/*
	* 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)
	{
	unsigned long random_factor = 0UL;

	if (current->flags & PF_RANDOMIZE)
	random_factor = mmap_rnd();

	/*
	* Fall back to the standard layout if the personality
	* bit is set, or if the expected stack growth is unlimited:
	*/
	if (mmap_is_legacy()) {
	mm->mmap_base = mmap_base_legacy(random_factor);
	mm->get_unmapped_area = s390_get_unmapped_area;
	} else {
	mm->mmap_base = mmap_base(random_factor);
	mm->get_unmapped_area = s390_get_unmapped_area_topdown;
	}
	}

	static int __init setup_mmap_rnd(void)
	{
	struct cpuid cpu_id;

	get_cpu_id(&cpu_id);
	switch (cpu_id.machine) {
	case 0x9672:
	case 0x2064:
	case 0x2066:
	case 0x2084:
	case 0x2086:
	case 0x2094:
	case 0x2096:
	case 0x2097:
	case 0x2098:
	case 0x2817:
	case 0x2818:
	case 0x2827:
	case 0x2828:
	mmap_rnd_mask = 0x7ffUL;
	mmap_align_mask = 0UL;
	break;
	case 0x2964: /* z13 */
	default:
	mmap_rnd_mask = 0x3ff80UL;
	mmap_align_mask = 0x7fUL;
	break;
	}
	return 0;
	}
	early_initcall(setup_mmap_rnd);

	#endif