URL
https://opencores.org/ocsvn/or1k/or1k/trunk
Subversion Repositories or1k
[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [mm/] [mprotect.c] - Rev 1765
Compare with Previous | Blame | View Log
/* * linux/mm/mprotect.c * * (C) Copyright 1994 Linus Torvalds */ #include <linux/stat.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/shm.h> #include <linux/errno.h> #include <linux/mman.h> #include <linux/string.h> #include <linux/malloc.h> #include <asm/segment.h> #include <asm/system.h> #include <asm/pgtable.h> static inline void change_pte_range(pmd_t * pmd, unsigned long address, unsigned long size, pgprot_t newprot) { pte_t * pte; unsigned long end; if (pmd_none(*pmd)) return; if (pmd_bad(*pmd)) { printk("change_pte_range: bad pmd (%08lx)\n", pmd_val(*pmd)); pmd_clear(pmd); return; } pte = pte_offset(pmd, address); address &= ~PMD_MASK; end = address + size; if (end > PMD_SIZE) end = PMD_SIZE; do { pte_t entry = *pte; if (pte_present(entry)) set_pte(pte, pte_modify(entry, newprot)); address += PAGE_SIZE; pte++; } while (address < end); } static inline void change_pmd_range(pgd_t * pgd, unsigned long address, unsigned long size, pgprot_t newprot) { pmd_t * pmd; unsigned long end; if (pgd_none(*pgd)) return; if (pgd_bad(*pgd)) { printk("change_pmd_range: bad pgd (%08lx)\n", pgd_val(*pgd)); pgd_clear(pgd); return; } pmd = pmd_offset(pgd, address); address &= ~PGDIR_MASK; end = address + size; if (end > PGDIR_SIZE) end = PGDIR_SIZE; do { change_pte_range(pmd, address, end - address, newprot); address = (address + PMD_SIZE) & PMD_MASK; pmd++; } while (address < end); } static void change_protection(unsigned long start, unsigned long end, pgprot_t newprot) { pgd_t *dir; unsigned long beg = start; dir = pgd_offset(current->mm, start); flush_cache_range(current->mm, beg, end); while (start < end) { change_pmd_range(dir, start, end - start, newprot); start = (start + PGDIR_SIZE) & PGDIR_MASK; dir++; } flush_tlb_range(current->mm, beg, end); return; } static inline int mprotect_fixup_all(struct vm_area_struct * vma, int newflags, pgprot_t prot) { vma->vm_flags = newflags; vma->vm_page_prot = prot; return 0; } static inline int mprotect_fixup_start(struct vm_area_struct * vma, unsigned long end, int newflags, pgprot_t prot) { struct vm_area_struct * n; n = (struct vm_area_struct *) kmalloc(sizeof(struct vm_area_struct), GFP_KERNEL); if (!n) return -ENOMEM; *n = *vma; vma->vm_start = end; n->vm_end = end; vma->vm_offset += vma->vm_start - n->vm_start; n->vm_flags = newflags; n->vm_page_prot = prot; if (n->vm_inode) n->vm_inode->i_count++; if (n->vm_ops && n->vm_ops->open) n->vm_ops->open(n); insert_vm_struct(current->mm, n); return 0; } static inline int mprotect_fixup_end(struct vm_area_struct * vma, unsigned long start, int newflags, pgprot_t prot) { struct vm_area_struct * n; n = (struct vm_area_struct *) kmalloc(sizeof(struct vm_area_struct), GFP_KERNEL); if (!n) return -ENOMEM; *n = *vma; vma->vm_end = start; n->vm_start = start; n->vm_offset += n->vm_start - vma->vm_start; n->vm_flags = newflags; n->vm_page_prot = prot; if (n->vm_inode) n->vm_inode->i_count++; if (n->vm_ops && n->vm_ops->open) n->vm_ops->open(n); insert_vm_struct(current->mm, n); return 0; } static inline int mprotect_fixup_middle(struct vm_area_struct * vma, unsigned long start, unsigned long end, int newflags, pgprot_t prot) { struct vm_area_struct * left, * right; left = (struct vm_area_struct *) kmalloc(sizeof(struct vm_area_struct), GFP_KERNEL); if (!left) return -ENOMEM; right = (struct vm_area_struct *) kmalloc(sizeof(struct vm_area_struct), GFP_KERNEL); if (!right) { kfree(left); return -ENOMEM; } *left = *vma; *right = *vma; left->vm_end = start; vma->vm_start = start; vma->vm_end = end; right->vm_start = end; vma->vm_offset += vma->vm_start - left->vm_start; right->vm_offset += right->vm_start - left->vm_start; vma->vm_flags = newflags; vma->vm_page_prot = prot; if (vma->vm_inode) vma->vm_inode->i_count += 2; if (vma->vm_ops && vma->vm_ops->open) { vma->vm_ops->open(left); vma->vm_ops->open(right); } insert_vm_struct(current->mm, left); insert_vm_struct(current->mm, right); return 0; } static int mprotect_fixup(struct vm_area_struct * vma, unsigned long start, unsigned long end, unsigned int newflags) { pgprot_t newprot; int error; if (newflags == vma->vm_flags) return 0; newprot = protection_map[newflags & 0xf]; if (start == vma->vm_start) if (end == vma->vm_end) error = mprotect_fixup_all(vma, newflags, newprot); else error = mprotect_fixup_start(vma, end, newflags, newprot); else if (end == vma->vm_end) error = mprotect_fixup_end(vma, start, newflags, newprot); else error = mprotect_fixup_middle(vma, start, end, newflags, newprot); if (error) return error; change_protection(start, end, newprot); return 0; } asmlinkage int sys_mprotect(unsigned long start, size_t len, unsigned long prot) { unsigned long nstart, end, tmp; struct vm_area_struct * vma, * next; int error; if (start & ~PAGE_MASK) return -EINVAL; len = (len + ~PAGE_MASK) & PAGE_MASK; end = start + len; if (end < start) return -EINVAL; if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC)) return -EINVAL; if (end == start) return 0; vma = find_vma(current->mm, start); if (!vma || vma->vm_start > start) return -EFAULT; for (nstart = start ; ; ) { unsigned int newflags; /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ newflags = prot | (vma->vm_flags & ~(PROT_READ | PROT_WRITE | PROT_EXEC)); if ((newflags & ~(newflags >> 4)) & 0xf) { error = -EACCES; break; } if (vma->vm_end >= end) { error = mprotect_fixup(vma, nstart, end, newflags); break; } tmp = vma->vm_end; next = vma->vm_next; error = mprotect_fixup(vma, nstart, tmp, newflags); if (error) break; nstart = tmp; vma = next; if (!vma || vma->vm_start != nstart) { error = -EFAULT; break; } } merge_segments(current->mm, start, end); return error; }