/* cpd_get_private_area: This function attempts to allocate an address inside
* the process 32MB relocated area of its address space. If no suitable
* region is found cpd_get_alloced_area() is called.
*
* Notes:
* - vma_p will never be NULL as a 4KB dummy VMA is mapped at 31MB.
* - vma__prev_p will never be NULL as the brk vm_area is there or the loop
* invarient has failed.
*/
unsigned long
cpd_get_private_area(struct file *file_p, unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags)
{
unsigned int start, end;
struct vm_area_struct* vma_p;
struct vm_area_struct* vma_prev_p;
if (len < ARMPID_BRK_LIMIT) {
/* Loop till we hit brk */
for (start = end = ARMPID_BRK_LIMIT;
start >= PAGE_SIZE && len < end;
end = vma_prev_p->vm_start) {
start = end - len;
vma_p = find_vma_prev(current->mm, end, &vma_prev_p);
if (start >= vma_prev_p->vm_end) {
return start;
}
if (!vma_prev_p) {
break;
}
}
}
return cpd_get_alloced_area(file_p, addr, len, pgoff, flags);
}
/*
* A virtual address region being munmap()ed might share bounds table
* with adjacent VMAs. We only need to free the backing physical
* memory of these shared bounds tables entries covered in this virtual
* address region.
*/
static int unmap_edge_bts(struct mm_struct *mm,
unsigned long start, unsigned long end)
{
int ret;
long __user *bde_start, *bde_end;
struct vm_area_struct *prev, *next;
bool prev_shared = false, next_shared = false;
bde_start = mm->bd_addr + MPX_GET_BD_ENTRY_OFFSET(start);
bde_end = mm->bd_addr + MPX_GET_BD_ENTRY_OFFSET(end-1);
/*
* Check whether bde_start and bde_end are shared with adjacent
* VMAs.
*
* We already unliked the VMAs from the mm's rbtree so 'start'
* is guaranteed to be in a hole. This gets us the first VMA
* before the hole in to 'prev' and the next VMA after the hole
* in to 'next'.
*/
next = find_vma_prev(mm, start, &prev);
if (prev && (mm->bd_addr + MPX_GET_BD_ENTRY_OFFSET(prev->vm_end-1))
== bde_start)
prev_shared = true;
if (next && (mm->bd_addr + MPX_GET_BD_ENTRY_OFFSET(next->vm_start))
== bde_end)
next_shared = true;
/*
* This virtual address region being munmap()ed is only
* covered by one bounds table.
*
* In this case, if this table is also shared with adjacent
* VMAs, only part of the backing physical memory of the bounds
* table need be freeed. Otherwise the whole bounds table need
* be unmapped.
*/
if (bde_start == bde_end) {
return unmap_shared_bt(mm, bde_start, start, end,
prev_shared, next_shared);
}
/*
* If more than one bounds tables are covered in this virtual
* address region being munmap()ed, we need to separately check
* whether bde_start and bde_end are shared with adjacent VMAs.
*/
ret = unmap_shared_bt(mm, bde_start, start, end, prev_shared, false);
if (ret)
return ret;
ret = unmap_shared_bt(mm, bde_end, start, end, false, next_shared);
if (ret)
return ret;
return 0;
}
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, *prev;
unsigned long task_size = TASK_SIZE;
int do_color_align, last_mmap;
struct vm_unmapped_area_info info;
if (len > task_size)
return -ENOMEM;
do_color_align = 0;
if (filp || (flags & MAP_SHARED))
do_color_align = 1;
last_mmap = GET_LAST_MMAP(filp);
if (flags & MAP_FIXED) {
if ((flags & MAP_SHARED) && last_mmap &&
(addr - shared_align_offset(last_mmap, pgoff))
& (SHM_COLOUR - 1))
return -EINVAL;
goto found_addr;
}
if (addr) {
if (do_color_align && last_mmap)
addr = COLOR_ALIGN(addr, last_mmap, pgoff);
else
addr = PAGE_ALIGN(addr);
vma = find_vma_prev(mm, addr, &prev);
if (task_size - len >= addr &&
(!vma || addr + len <= vm_start_gap(vma)) &&
(!prev || addr >= vm_end_gap(prev)))
goto found_addr;
}
info.flags = 0;
info.length = len;
info.low_limit = mm->mmap_legacy_base;
info.high_limit = mmap_upper_limit();
info.align_mask = last_mmap ? (PAGE_MASK & (SHM_COLOUR - 1)) : 0;
info.align_offset = shared_align_offset(last_mmap, pgoff);
addr = vm_unmapped_area(&info);
found_addr:
if (do_color_align && !last_mmap && !(addr & ~PAGE_MASK))
SET_LAST_MMAP(filp, addr - (pgoff << PAGE_SHIFT));
return addr;
}
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, *prev_vma;
struct mm_struct *mm = current->mm;
unsigned long base = mm->mmap_base, addr = addr0;
int first_time = 1;
unsigned long begin, end;
find_start_end(flags, &begin, &end);
/* requested length too big for entire address space */
if (len > end)
return -ENOMEM;
/* dont allow allocations above current base */
if (mm->free_area_cache > base)
mm->free_area_cache = base;
/* requesting a specific address */
if (addr) {
addr = PAGE_ALIGN(addr);
vma = find_vma(mm, addr);
if (end - len >= addr &&
(!vma || addr + len <= vma->vm_start))
return addr;
}
/* free_area_cache is not really optimized for 32 bit apps */
if (sysctl_legacy_va_layout && ((flags & MAP_32BIT) || test_thread_flag(TIF_IA32)))
goto fail;
try_again:
/* make sure it can fit in the remaining address space */
if (mm->free_area_cache < len)
goto fail;
/* either no address requested or cant fit in requested address hole */
addr = (mm->free_area_cache - len) & PAGE_MASK;
do {
/*
* Lookup failure means no vma is above this address,
* i.e. return with success:
*/
if (!(vma = find_vma_prev(mm, addr, &prev_vma)))
return addr;
/*
* new region fits between prev_vma->vm_end and
* vma->vm_start, use it:
*/
if (addr && addr+len <= vma->vm_start &&
(!prev_vma || (addr >= prev_vma->vm_end)))
/* remember the address as a hint for next time */
return (mm->free_area_cache = addr);
else
/* pull free_area_cache down to the first hole */
if (mm->free_area_cache == vma->vm_end)
mm->free_area_cache = vma->vm_start;
/* try just below the current vma->vm_start */
addr = vma->vm_start-len;
} while (len < vma->vm_start);
fail:
/*
* if hint left us with no space for the requested
* mapping then try again:
*/
if (first_time) {
mm->free_area_cache = base;
first_time = 0;
goto try_again;
}
/*
* 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.
*/
mm->free_area_cache = begin;
addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
/*
* Restore the topdown base:
*/
mm->free_area_cache = base;
return addr;
}
static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
unsigned long addr0, unsigned long len,
unsigned long pgoff, unsigned long flags)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma, *prev_vma;
unsigned long base = mm->mmap_base, addr = addr0;
unsigned long largest_hole = mm->cached_hole_size;
int first_time = 1;
/* don't allow allocations above current base */
if (mm->free_area_cache > base)
mm->free_area_cache = base;
if (len <= largest_hole) {
largest_hole = 0;
mm->free_area_cache = base;
}
try_again:
/* make sure it can fit in the remaining address space */
if (mm->free_area_cache < len)
goto fail;
/* either no address requested or cant fit in requested address hole */
addr = (mm->free_area_cache - len) & HPAGE_MASK;
do {
/*
* Lookup failure means no vma is above this address,
* i.e. return with success:
*/
if (!(vma = find_vma_prev(mm, addr, &prev_vma)))
return addr;
/*
* new region fits between prev_vma->vm_end and
* vma->vm_start, use it:
*/
if (addr + len <= vma->vm_start &&
(!prev_vma || (addr >= prev_vma->vm_end))) {
/* remember the address as a hint for next time */
mm->cached_hole_size = largest_hole;
return (mm->free_area_cache = addr);
} else {
/* pull free_area_cache down to the first hole */
if (mm->free_area_cache == vma->vm_end) {
mm->free_area_cache = vma->vm_start;
mm->cached_hole_size = largest_hole;
}
}
/* remember the largest hole we saw so far */
if (addr + largest_hole < vma->vm_start)
largest_hole = vma->vm_start - addr;
/* try just below the current vma->vm_start */
addr = (vma->vm_start - len) & HPAGE_MASK;
} while (len <= vma->vm_start);
fail:
/*
* if hint left us with no space for the requested
* mapping then try again:
*/
if (first_time) {
mm->free_area_cache = base;
largest_hole = 0;
first_time = 0;
goto try_again;
}
/*
* 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.
*/
mm->free_area_cache = TASK_UNMAPPED_BASE;
mm->cached_hole_size = ~0UL;
addr = hugetlb_get_unmapped_area_bottomup(file, addr0,
len, pgoff, flags);
/*
* Restore the topdown base:
*/
mm->free_area_cache = base;
mm->cached_hole_size = ~0UL;
return addr;
}
static inline unsigned long move_vma(struct vm_area_struct * vma,
unsigned long addr, unsigned long old_len, unsigned long new_len,
unsigned long new_addr)
{
struct mm_struct * mm = vma->vm_mm;
struct vm_area_struct * new_vma, * next, * prev;
int allocated_vma;
new_vma = NULL;
next = find_vma_prev(mm, new_addr, &prev);
if (next) {
if (prev && prev->vm_end == new_addr &&
can_vma_merge(prev, vma->vm_flags) && !vma->vm_file && !(vma->vm_flags & VM_SHARED)) {
spin_lock(&mm->page_table_lock);
prev->vm_end = new_addr + new_len;
spin_unlock(&mm->page_table_lock);
new_vma = prev;
if (next != prev->vm_next)
BUG();
if (prev->vm_end == next->vm_start && can_vma_merge(next, prev->vm_flags)) {
spin_lock(&mm->page_table_lock);
prev->vm_end = next->vm_end;
__vma_unlink(mm, next, prev);
spin_unlock(&mm->page_table_lock);
mm->map_count--;
kmem_cache_free(vm_area_cachep, next);
}
} else if (next->vm_start == new_addr + new_len &&
can_vma_merge(next, vma->vm_flags) && !vma->vm_file && !(vma->vm_flags & VM_SHARED)) {
spin_lock(&mm->page_table_lock);
next->vm_start = new_addr;
spin_unlock(&mm->page_table_lock);
new_vma = next;
}
} else {
prev = find_vma(mm, new_addr-1);
if (prev && prev->vm_end == new_addr &&
can_vma_merge(prev, vma->vm_flags) && !vma->vm_file && !(vma->vm_flags & VM_SHARED)) {
spin_lock(&mm->page_table_lock);
prev->vm_end = new_addr + new_len;
spin_unlock(&mm->page_table_lock);
new_vma = prev;
}
}
allocated_vma = 0;
if (!new_vma) {
new_vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
if (!new_vma)
goto out;
allocated_vma = 1;
}
if (!move_page_tables(current->mm, new_addr, addr, old_len)) {
unsigned long vm_locked = vma->vm_flags & VM_LOCKED;
if (allocated_vma) {
*new_vma = *vma;
new_vma->vm_start = new_addr;
new_vma->vm_end = new_addr+new_len;
new_vma->vm_pgoff += (addr-vma->vm_start) >> PAGE_SHIFT;
new_vma->vm_raend = 0;
if (new_vma->vm_file)
get_file(new_vma->vm_file);
if (new_vma->vm_ops && new_vma->vm_ops->open)
new_vma->vm_ops->open(new_vma);
insert_vm_struct(current->mm, new_vma);
}
/* XXX: possible errors masked, mapping might remain */
do_munmap(current->mm, addr, old_len);
current->mm->total_vm += new_len >> PAGE_SHIFT;
if (vm_locked) {
current->mm->locked_vm += new_len >> PAGE_SHIFT;
if (new_len > old_len)
make_pages_present(new_addr + old_len,
new_addr + new_len);
}
return new_addr;
}
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, *prev;
struct mm_struct *mm = current->mm;
unsigned long addr = addr0;
int do_color_align, last_mmap;
struct vm_unmapped_area_info info;
#ifdef CONFIG_64BIT
/* This should only ever run for 32-bit processes. */
BUG_ON(!test_thread_flag(TIF_32BIT));
#endif
/* requested length too big for entire address space */
if (len > TASK_SIZE)
return -ENOMEM;
do_color_align = 0;
if (filp || (flags & MAP_SHARED))
do_color_align = 1;
last_mmap = GET_LAST_MMAP(filp);
if (flags & MAP_FIXED) {
if ((flags & MAP_SHARED) && last_mmap &&
(addr - shared_align_offset(last_mmap, pgoff))
& (SHM_COLOUR - 1))
return -EINVAL;
goto found_addr;
}
/* requesting a specific address */
if (addr) {
if (do_color_align && last_mmap)
addr = COLOR_ALIGN(addr, last_mmap, pgoff);
else
addr = PAGE_ALIGN(addr);
vma = find_vma_prev(mm, addr, &prev);
if (TASK_SIZE - len >= addr &&
(!vma || addr + len <= vm_start_gap(vma)) &&
(!prev || addr >= vm_end_gap(prev)))
goto found_addr;
}
info.flags = VM_UNMAPPED_AREA_TOPDOWN;
info.length = len;
info.low_limit = PAGE_SIZE;
info.high_limit = mm->mmap_base;
info.align_mask = last_mmap ? (PAGE_MASK & (SHM_COLOUR - 1)) : 0;
info.align_offset = shared_align_offset(last_mmap, pgoff);
addr = vm_unmapped_area(&info);
if (!(addr & ~PAGE_MASK))
goto found_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 arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
found_addr:
if (do_color_align && !last_mmap && !(addr & ~PAGE_MASK))
SET_LAST_MMAP(filp, addr - (pgoff << PAGE_SHIFT));
return addr;
}
static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
unsigned long addr0, unsigned long len,
unsigned long pgoff, unsigned long flags)
{
struct hstate *h = hstate_file(file);
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma, *prev_vma;
unsigned long base = mm->mmap_base, addr = addr0;
unsigned long largest_hole = mm->cached_hole_size;
int first_time = 1;
if (mm->free_area_cache > base)
mm->free_area_cache = base;
if (len <= largest_hole) {
largest_hole = 0;
mm->free_area_cache = base;
}
try_again:
if (mm->free_area_cache < len)
goto fail;
addr = (mm->free_area_cache - len) & huge_page_mask(h);
do {
vma = find_vma_prev(mm, addr, &prev_vma);
if (!vma) {
return addr;
break;
}
if (addr + len <= vma->vm_start &&
(!prev_vma || (addr >= prev_vma->vm_end))) {
mm->cached_hole_size = largest_hole;
mm->free_area_cache = addr;
return addr;
} else {
if (mm->free_area_cache == vma->vm_end) {
mm->free_area_cache = vma->vm_start;
mm->cached_hole_size = largest_hole;
}
}
if (addr + largest_hole < vma->vm_start)
largest_hole = vma->vm_start - addr;
addr = (vma->vm_start - len) & huge_page_mask(h);
} while (len <= vma->vm_start);
fail:
if (first_time) {
mm->free_area_cache = base;
largest_hole = 0;
first_time = 0;
goto try_again;
}
mm->free_area_cache = TASK_UNMAPPED_BASE;
mm->cached_hole_size = ~0UL;
addr = hugetlb_get_unmapped_area_bottomup(file, addr0,
len, pgoff, flags);
mm->free_area_cache = base;
mm->cached_hole_size = ~0UL;
return addr;
}