unsigned long
arch_get_unmapped_area (struct file *filp, unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags)
{
long map_shared = (flags & MAP_SHARED);
unsigned long start_addr, align_mask = PAGE_SIZE - 1;
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
if (len > RGN_MAP_LIMIT)
return -ENOMEM;
/* handle fixed mapping: prevent overlap with huge pages */
if (flags & MAP_FIXED) {
if (is_hugepage_only_range(mm, addr, len))
return -EINVAL;
return addr;
}
#ifdef CONFIG_HUGETLB_PAGE
if (REGION_NUMBER(addr) == RGN_HPAGE)
addr = 0;
#endif
if (!addr)
addr = mm->free_area_cache;
if (map_shared && (TASK_SIZE > 0xfffffffful))
/*
* For 64-bit tasks, align shared segments to 1MB to avoid potential
* performance penalty due to virtual aliasing (see ASDM). For 32-bit
* tasks, we prefer to avoid exhausting the address space too quickly by
* limiting alignment to a single page.
*/
align_mask = SHMLBA - 1;
full_search:
start_addr = addr = (addr + align_mask) & ~align_mask;
for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
/* At this point: (!vma || addr < vma->vm_end). */
if (TASK_SIZE - len < addr || RGN_MAP_LIMIT - len < REGION_OFFSET(addr)) {
if (start_addr != TASK_UNMAPPED_BASE) {
/* Start a new search --- just in case we missed some holes. */
addr = TASK_UNMAPPED_BASE;
goto full_search;
}
return -ENOMEM;
}
if (!vma || addr + len <= vma->vm_start) {
/* Remember the address where we stopped this search: */
mm->free_area_cache = addr + len;
return addr;
}
addr = (vma->vm_end + align_mask) & ~align_mask;
}
}
unsigned long
arch_get_unmapped_area (struct file *filp, unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags)
{
long map_shared = (flags & MAP_SHARED);
unsigned long align_mask = 0;
struct mm_struct *mm = current->mm;
struct vm_unmapped_area_info info;
unsigned long offset = gr_rand_threadstack_offset(mm, filp, flags);
if (len > RGN_MAP_LIMIT)
return -ENOMEM;
/* handle fixed mapping: prevent overlap with huge pages */
if (flags & MAP_FIXED) {
if (is_hugepage_only_range(mm, addr, len))
return -EINVAL;
return addr;
}
#ifdef CONFIG_HUGETLB_PAGE
if (REGION_NUMBER(addr) == RGN_HPAGE)
addr = 0;
#endif
#ifdef CONFIG_PAX_RANDMMAP
if (mm->pax_flags & MF_PAX_RANDMMAP)
addr = mm->free_area_cache;
else
#endif
if (!addr)
addr = TASK_UNMAPPED_BASE;
if (map_shared && (TASK_SIZE > 0xfffffffful))
/*
* For 64-bit tasks, align shared segments to 1MB to avoid potential
* performance penalty due to virtual aliasing (see ASDM). For 32-bit
* tasks, we prefer to avoid exhausting the address space too quickly by
* limiting alignment to a single page.
*/
align_mask = PAGE_MASK & (SHMLBA - 1);
info.flags = 0;
info.length = len;
info.low_limit = addr;
info.high_limit = TASK_SIZE;
info.align_mask = align_mask;
info.align_offset = 0;
info.threadstack_offset = offset;
return vm_unmapped_area(&info);
}