4 * (C) Copyright 1994 Linus Torvalds
5 * (C) Copyright 2002 Christoph Hellwig
7 * Address space accounting code <alan@lxorguk.ukuu.org.uk>
8 * (C) Copyright 2002 Red Hat Inc, All Rights Reserved
12 #include <linux/hugetlb.h>
13 #include <linux/shm.h>
14 #include <linux/mman.h>
16 #include <linux/highmem.h>
17 #include <linux/security.h>
18 #include <linux/mempolicy.h>
19 #include <linux/personality.h>
20 #include <linux/syscalls.h>
21 #include <linux/swap.h>
22 #include <linux/swapops.h>
23 #include <linux/mmu_notifier.h>
24 #include <linux/migrate.h>
25 #include <linux/perf_event.h>
26 #include <asm/uaccess.h>
27 #include <asm/pgtable.h>
28 #include <asm/cacheflush.h>
29 #include <asm/tlbflush.h>
32 static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
38 static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
39 unsigned long addr, unsigned long end, pgprot_t newprot,
40 int dirty_accountable, int prot_numa, bool *ret_all_same_nidpid)
42 struct mm_struct *mm = vma->vm_mm;
45 unsigned long pages = 0;
46 bool all_same_nidpid = true;
50 pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
51 arch_enter_lazy_mmu_mode();
54 if (pte_present(oldpte)) {
58 ptent = ptep_modify_prot_start(mm, addr, pte);
60 ptent = pte_modify(ptent, newprot);
65 page = vm_normal_page(vma, addr, oldpte);
67 int nidpid = page_nidpid_last(page);
68 int this_nid = nidpid_to_nid(nidpid);
69 int this_pid = nidpid_to_pid(nidpid);
75 if (last_nid != this_nid ||
76 last_pid != this_pid) {
77 all_same_nidpid = false;
80 if (!pte_numa(oldpte)) {
81 ptent = pte_mknuma(ptent);
88 * Avoid taking write faults for pages we know to be
91 if (dirty_accountable && pte_dirty(ptent)) {
92 ptent = pte_mkwrite(ptent);
98 ptep_modify_prot_commit(mm, addr, pte, ptent);
99 } else if (IS_ENABLED(CONFIG_MIGRATION) && !pte_file(oldpte)) {
100 swp_entry_t entry = pte_to_swp_entry(oldpte);
102 if (is_write_migration_entry(entry)) {
104 * A protection check is difficult so
105 * just be safe and disable write
107 make_migration_entry_read(&entry);
108 set_pte_at(mm, addr, pte,
109 swp_entry_to_pte(entry));
114 } while (pte++, addr += PAGE_SIZE, addr != end);
115 arch_leave_lazy_mmu_mode();
116 pte_unmap_unlock(pte - 1, ptl);
118 *ret_all_same_nidpid = all_same_nidpid;
122 #ifdef CONFIG_NUMA_BALANCING
123 static inline void change_pmd_protnuma(struct mm_struct *mm, unsigned long addr,
126 spin_lock(&mm->page_table_lock);
127 set_pmd_at(mm, addr & PMD_MASK, pmd, pmd_mknuma(*pmd));
128 spin_unlock(&mm->page_table_lock);
131 static inline void change_pmd_protnuma(struct mm_struct *mm, unsigned long addr,
136 #endif /* CONFIG_NUMA_BALANCING */
138 static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
139 pud_t *pud, unsigned long addr, unsigned long end,
140 pgprot_t newprot, int dirty_accountable, int prot_numa)
144 unsigned long pages = 0;
145 bool all_same_nidpid;
147 pmd = pmd_offset(pud, addr);
149 next = pmd_addr_end(addr, end);
150 if (pmd_trans_huge(*pmd)) {
151 if (next - addr != HPAGE_PMD_SIZE)
152 split_huge_page_pmd(vma, addr, pmd);
154 int nr_ptes = change_huge_pmd(vma, pmd, addr,
158 if (nr_ptes == HPAGE_PMD_NR)
166 if (pmd_none_or_clear_bad(pmd))
168 pages += change_pte_range(vma, pmd, addr, next, newprot,
169 dirty_accountable, prot_numa, &all_same_nidpid);
172 * If we are changing protections for NUMA hinting faults then
173 * set pmd_numa if the examined pages were all on the same
174 * node. This allows a regular PMD to be handled as one fault
175 * and effectively batches the taking of the PTL
177 if (prot_numa && all_same_nidpid)
178 change_pmd_protnuma(vma->vm_mm, addr, pmd);
179 } while (pmd++, addr = next, addr != end);
184 static inline unsigned long change_pud_range(struct vm_area_struct *vma,
185 pgd_t *pgd, unsigned long addr, unsigned long end,
186 pgprot_t newprot, int dirty_accountable, int prot_numa)
190 unsigned long pages = 0;
192 pud = pud_offset(pgd, addr);
194 next = pud_addr_end(addr, end);
195 if (pud_none_or_clear_bad(pud))
197 pages += change_pmd_range(vma, pud, addr, next, newprot,
198 dirty_accountable, prot_numa);
199 } while (pud++, addr = next, addr != end);
204 static unsigned long change_protection_range(struct vm_area_struct *vma,
205 unsigned long addr, unsigned long end, pgprot_t newprot,
206 int dirty_accountable, int prot_numa)
208 struct mm_struct *mm = vma->vm_mm;
211 unsigned long start = addr;
212 unsigned long pages = 0;
215 pgd = pgd_offset(mm, addr);
216 flush_cache_range(vma, addr, end);
218 next = pgd_addr_end(addr, end);
219 if (pgd_none_or_clear_bad(pgd))
221 pages += change_pud_range(vma, pgd, addr, next, newprot,
222 dirty_accountable, prot_numa);
223 } while (pgd++, addr = next, addr != end);
225 /* Only flush the TLB if we actually modified any entries: */
227 flush_tlb_range(vma, start, end);
232 unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
233 unsigned long end, pgprot_t newprot,
234 int dirty_accountable, int prot_numa)
236 struct mm_struct *mm = vma->vm_mm;
239 mmu_notifier_invalidate_range_start(mm, start, end);
240 if (is_vm_hugetlb_page(vma))
241 pages = hugetlb_change_protection(vma, start, end, newprot);
243 pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa);
244 mmu_notifier_invalidate_range_end(mm, start, end);
250 mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
251 unsigned long start, unsigned long end, unsigned long newflags)
253 struct mm_struct *mm = vma->vm_mm;
254 unsigned long oldflags = vma->vm_flags;
255 long nrpages = (end - start) >> PAGE_SHIFT;
256 unsigned long charged = 0;
259 int dirty_accountable = 0;
261 if (newflags == oldflags) {
267 * If we make a private mapping writable we increase our commit;
268 * but (without finer accounting) cannot reduce our commit if we
269 * make it unwritable again. hugetlb mapping were accounted for
270 * even if read-only so there is no need to account for them here
272 if (newflags & VM_WRITE) {
273 if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB|
274 VM_SHARED|VM_NORESERVE))) {
276 if (security_vm_enough_memory_mm(mm, charged))
278 newflags |= VM_ACCOUNT;
283 * First try to merge with previous and/or next vma.
285 pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
286 *pprev = vma_merge(mm, *pprev, start, end, newflags,
287 vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma));
295 if (start != vma->vm_start) {
296 error = split_vma(mm, vma, start, 1);
301 if (end != vma->vm_end) {
302 error = split_vma(mm, vma, end, 0);
309 * vm_flags and vm_page_prot are protected by the mmap_sem
310 * held in write mode.
312 vma->vm_flags = newflags;
313 vma->vm_page_prot = pgprot_modify(vma->vm_page_prot,
314 vm_get_page_prot(newflags));
316 if (vma_wants_writenotify(vma)) {
317 vma->vm_page_prot = vm_get_page_prot(newflags & ~VM_SHARED);
318 dirty_accountable = 1;
321 change_protection(vma, start, end, vma->vm_page_prot,
322 dirty_accountable, 0);
324 vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
325 vm_stat_account(mm, newflags, vma->vm_file, nrpages);
326 perf_event_mmap(vma);
330 vm_unacct_memory(charged);
334 SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
337 unsigned long vm_flags, nstart, end, tmp, reqprot;
338 struct vm_area_struct *vma, *prev;
340 const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP);
341 prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP);
342 if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */
345 if (start & ~PAGE_MASK)
349 len = PAGE_ALIGN(len);
353 if (!arch_validate_prot(prot))
358 * Does the application expect PROT_READ to imply PROT_EXEC:
360 if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
363 vm_flags = calc_vm_prot_bits(prot);
365 down_write(¤t->mm->mmap_sem);
367 vma = find_vma(current->mm, start);
372 if (unlikely(grows & PROT_GROWSDOWN)) {
373 if (vma->vm_start >= end)
375 start = vma->vm_start;
377 if (!(vma->vm_flags & VM_GROWSDOWN))
380 if (vma->vm_start > start)
382 if (unlikely(grows & PROT_GROWSUP)) {
385 if (!(vma->vm_flags & VM_GROWSUP))
389 if (start > vma->vm_start)
392 for (nstart = start ; ; ) {
393 unsigned long newflags;
395 /* Here we know that vma->vm_start <= nstart < vma->vm_end. */
398 newflags |= (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC));
400 /* newflags >> 4 shift VM_MAY% in place of VM_% */
401 if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) {
406 error = security_file_mprotect(vma, reqprot, prot);
413 error = mprotect_fixup(vma, &prev, nstart, tmp, newflags);
418 if (nstart < prev->vm_end)
419 nstart = prev->vm_end;
424 if (!vma || vma->vm_start != nstart) {
430 up_write(¤t->mm->mmap_sem);