[linux-block.git] / arch / arm / mm / mmap.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/arch/arm/mm/mmap.c
 */
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/shm.h>
#include <linux/sched/signal.h>
#include <linux/sched/mm.h>
#include <linux/io.h>
#include <linux/personality.h>
#include <linux/random.h>
#include <asm/cachetype.h>

#define COLOUR_ALIGN(addr,pgoff)		\
	((((addr)+SHMLBA-1)&~(SHMLBA-1)) +	\
	 (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))

/*
 * We need to ensure that shared mappings are correctly aligned to
 * avoid aliasing issues with VIPT caches.  We need to ensure that
 * a specific page of an object is always mapped at a multiple of
 * SHMLBA bytes.
 *
 * We unconditionally provide this function for all cases, however
 * in the VIVT case, we optimise out the alignment rules.
 */
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;
	int do_align = 0;
	int aliasing = cache_is_vipt_aliasing();
	struct vm_unmapped_area_info info = {};

	/*
	 * We only need to do colour alignment if either the I or D
	 * caches alias.
	 */
	if (aliasing)
		do_align = filp || (flags & MAP_SHARED);

	/*
	 * We enforce the MAP_FIXED case.
	 */
	if (flags & MAP_FIXED) {
		if (aliasing && flags & MAP_SHARED &&
		    (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
			return -EINVAL;
		return addr;
	}

	if (len > TASK_SIZE)
		return -ENOMEM;

	if (addr) {
		if (do_align)
			addr = COLOUR_ALIGN(addr, pgoff);
		else
			addr = PAGE_ALIGN(addr);

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

	info.length = len;
	info.low_limit = mm->mmap_base;
	info.high_limit = TASK_SIZE;
	info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 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;
	int do_align = 0;
	int aliasing = cache_is_vipt_aliasing();
	struct vm_unmapped_area_info info = {};

	/*
	 * We only need to do colour alignment if either the I or D
	 * caches alias.
	 */
	if (aliasing)
		do_align = filp || (flags & MAP_SHARED);

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

	if (flags & MAP_FIXED) {
		if (aliasing && flags & MAP_SHARED &&
		    (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
			return -EINVAL;
		return addr;
	}

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

	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
	info.length = len;
	info.low_limit = FIRST_USER_ADDRESS;
	info.high_limit = mm->mmap_base;
	info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 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 = mm->mmap_base;
		info.high_limit = TASK_SIZE;
		addr = vm_unmapped_area(&info);
	}

	return addr;
}

/*
 * You really shouldn't be using read() or write() on /dev/mem.  This
 * might go away in the future.
 */
int valid_phys_addr_range(phys_addr_t addr, size_t size)
{
	if (addr < PHYS_OFFSET)
		return 0;
	if (addr + size > __pa(high_memory - 1) + 1)
		return 0;

	return 1;
}

/*
 * Do not allow /dev/mem mappings beyond the supported physical range.
 */
int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
{
	return (pfn + (size >> PAGE_SHIFT)) <= (1 + (PHYS_MASK >> PAGE_SHIFT));
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/arch/arm/mm/mmap.c
	4	*/
1da177e4 LT	5	#include <linux/fs.h>
	6	#include <linux/mm.h>
	7	#include <linux/mman.h>
	8	#include <linux/shm.h>
3f07c014	9	#include <linux/sched/signal.h>
01042607	10	#include <linux/sched/mm.h>
09d9bae0	11	#include <linux/io.h>
df5419a9	12	#include <linux/personality.h>
cc92c28b	13	#include <linux/random.h>
41dfaa93	14	#include <asm/cachetype.h>
1da177e4 LT	15
	16	#define COLOUR_ALIGN(addr,pgoff) \
	17	((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \
	18	(((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
	19
	20	/*
	21	* We need to ensure that shared mappings are correctly aligned to
	22	* avoid aliasing issues with VIPT caches. We need to ensure that
	23	* a specific page of an object is always mapped at a multiple of
	24	* SHMLBA bytes.
	25	*
	26	* We unconditionally provide this function for all cases, however
	27	* in the VIVT case, we optimise out the alignment rules.
	28	*/
	29	unsigned long
	30	arch_get_unmapped_area(struct file *filp, unsigned long addr,
	31	unsigned long len, unsigned long pgoff, unsigned long flags)
	32	{
	33	struct mm_struct *mm = current->mm;
	34	struct vm_area_struct *vma;
41dfaa93 RH	35	int do_align = 0;
41dfaa93 RH	36	int aliasing = cache_is_vipt_aliasing();
b80fa3cb	37	struct vm_unmapped_area_info info = {};
1da177e4 LT	38
	39	/*
	40	* We only need to do colour alignment if either the I or D
41dfaa93	41	* caches alias.
1da177e4	42	*/
41dfaa93 RH	43	if (aliasing)
41dfaa93 RH	44	do_align = filp \|\| (flags & MAP_SHARED);
1da177e4 LT	45
1da177e4 LT	46	/*
acec0ac0	47	* We enforce the MAP_FIXED case.
1da177e4 LT	48	*/
1da177e4 LT	49	if (flags & MAP_FIXED) {
e77414e0 AV	50	if (aliasing && flags & MAP_SHARED &&
e77414e0 AV	51	(addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
1da177e4 LT	52	return -EINVAL;
	53	return addr;
	54	}
	55
	56	if (len > TASK_SIZE)
	57	return -ENOMEM;
	58
	59	if (addr) {
	60	if (do_align)
	61	addr = COLOUR_ALIGN(addr, pgoff);
	62	else
	63	addr = PAGE_ALIGN(addr);
	64
	65	vma = find_vma(mm, addr);
	66	if (TASK_SIZE - len >= addr &&
1be7107f	67	(!vma \|\| addr + len <= vm_start_gap(vma)))
1da177e4 LT	68	return addr;
1da177e4 LT	69	}
1da177e4	70
394ef640 ML	71	info.length = len;
	72	info.low_limit = mm->mmap_base;
	73	info.high_limit = TASK_SIZE;
	74	info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
	75	info.align_offset = pgoff << PAGE_SHIFT;
	76	return vm_unmapped_area(&info);
1da177e4 LT	77	}
1da177e4 LT	78
7dbaa466 RH	79	unsigned long
	80	arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
	81	const unsigned long len, const unsigned long pgoff,
	82	const unsigned long flags)
	83	{
	84	struct vm_area_struct *vma;
	85	struct mm_struct *mm = current->mm;
	86	unsigned long addr = addr0;
	87	int do_align = 0;
	88	int aliasing = cache_is_vipt_aliasing();
b80fa3cb	89	struct vm_unmapped_area_info info = {};
7dbaa466 RH	90
	91	/*
	92	* We only need to do colour alignment if either the I or D
	93	* caches alias.
	94	*/
	95	if (aliasing)
	96	do_align = filp \|\| (flags & MAP_SHARED);
	97
	98	/* requested length too big for entire address space */
	99	if (len > TASK_SIZE)
	100	return -ENOMEM;
	101
	102	if (flags & MAP_FIXED) {
	103	if (aliasing && flags & MAP_SHARED &&
	104	(addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
	105	return -EINVAL;
	106	return addr;
	107	}
	108
	109	/* requesting a specific address */
	110	if (addr) {
	111	if (do_align)
	112	addr = COLOUR_ALIGN(addr, pgoff);
	113	else
	114	addr = PAGE_ALIGN(addr);
	115	vma = find_vma(mm, addr);
	116	if (TASK_SIZE - len >= addr &&
1be7107f	117	(!vma \|\| addr + len <= vm_start_gap(vma)))
7dbaa466 RH	118	return addr;
	119	}
	120
394ef640 ML	121	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
394ef640 ML	122	info.length = len;
d8aa712c	123	info.low_limit = FIRST_USER_ADDRESS;
394ef640 ML	124	info.high_limit = mm->mmap_base;
	125	info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
	126	info.align_offset = pgoff << PAGE_SHIFT;
	127	addr = vm_unmapped_area(&info);
7dbaa466	128
7dbaa466 RH	129	/*
	130	* A failed mmap() very likely causes application failure,
	131	* so fall back to the bottom-up function here. This scenario
	132	* can happen with large stack limits and large mmap()
	133	* allocations.
	134	*/
394ef640 ML	135	if (addr & ~PAGE_MASK) {
	136	VM_BUG_ON(addr != -ENOMEM);
	137	info.flags = 0;
	138	info.low_limit = mm->mmap_base;
	139	info.high_limit = TASK_SIZE;
	140	addr = vm_unmapped_area(&info);
	141	}
7dbaa466 RH	142
	143	return addr;
	144	}
	145
51635ad2 LB	146	/*
	147	* You really shouldn't be using read() or write() on /dev/mem. This
	148	* might go away in the future.
	149	*/
7e6735c3	150	int valid_phys_addr_range(phys_addr_t addr, size_t size)
51635ad2	151	{
9ae3ae0b AR	152	if (addr < PHYS_OFFSET)
9ae3ae0b AR	153	return 0;
6806bfe1	154	if (addr + size > __pa(high_memory - 1) + 1)
51635ad2 LB	155	return 0;
	156
	157	return 1;
	158	}
	159
	160	/*
3159f372	161	* Do not allow /dev/mem mappings beyond the supported physical range.
51635ad2 LB	162	*/
	163	int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
	164	{
3159f372	165	return (pfn + (size >> PAGE_SHIFT)) <= (1 + (PHYS_MASK >> PAGE_SHIFT));
51635ad2	166	}