#ifdef CONFIG_HAVE_RCU_TABLE_FREE
tlb->batch = NULL;
#endif
+ tlb->page_size = 0;
__tlb_reset_range(tlb);
}
* handling the additional races in SMP caused by other CPUs caching valid
* mappings in their TLBs. Returns the number of free page slots left.
* When out of page slots we must call tlb_flush_mmu().
+ *returns true if the caller should flush.
*/
-int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
+bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, int page_size)
{
struct mmu_gather_batch *batch;
VM_BUG_ON(!tlb->end);
+ if (!tlb->page_size)
+ tlb->page_size = page_size;
+ else {
+ if (page_size != tlb->page_size)
+ return true;
+ }
+
batch = tlb->active;
- batch->pages[batch->nr++] = page;
if (batch->nr == batch->max) {
if (!tlb_next_batch(tlb))
- return 0;
+ return true;
batch = tlb->active;
}
VM_BUG_ON_PAGE(batch->nr > batch->max, page);
- return batch->max - batch->nr;
+ batch->pages[batch->nr++] = page;
+ return false;
}
#endif /* HAVE_GENERIC_MMU_GATHER */
pte_t *start_pte;
pte_t *pte;
swp_entry_t entry;
+ struct page *pending_page = NULL;
again:
init_rss_vec(rss);
* unmap shared but keep private pages.
*/
if (details->check_mapping &&
- details->check_mapping != page->mapping)
+ details->check_mapping != page_rmapping(page))
continue;
}
ptent = ptep_get_and_clear_full(mm, addr, pte,
page_remove_rmap(page, false);
if (unlikely(page_mapcount(page) < 0))
print_bad_pte(vma, addr, ptent, page);
- if (unlikely(!__tlb_remove_page(tlb, page))) {
+ if (unlikely(__tlb_remove_page(tlb, page))) {
force_flush = 1;
+ pending_page = page;
addr += PAGE_SIZE;
break;
}
if (force_flush) {
force_flush = 0;
tlb_flush_mmu_free(tlb);
-
+ if (pending_page) {
+ /* remove the page with new size */
+ __tlb_remove_pte_page(tlb, pending_page);
+ pending_page = NULL;
+ }
if (addr != end)
goto again;
}
/* Ok, finally just insert the thing.. */
get_page(page);
inc_mm_counter_fast(mm, mm_counter_file(page));
- page_add_file_rmap(page);
+ page_add_file_rmap(page, false);
set_pte_at(mm, addr, pte, mk_pte(page, prot));
retval = 0;
* case, all we need to do here is to mark the page as writable and update
* any related book-keeping.
*/
-static inline int wp_page_reuse(struct mm_struct *mm,
- struct vm_area_struct *vma, unsigned long address,
- pte_t *page_table, spinlock_t *ptl, pte_t orig_pte,
- struct page *page, int page_mkwrite,
- int dirty_shared)
- __releases(ptl)
+static inline int wp_page_reuse(struct fault_env *fe, pte_t orig_pte,
+ struct page *page, int page_mkwrite, int dirty_shared)
+ __releases(fe->ptl)
{
+ struct vm_area_struct *vma = fe->vma;
pte_t entry;
/*
* Clear the pages cpupid information as the existing
if (page)
page_cpupid_xchg_last(page, (1 << LAST_CPUPID_SHIFT) - 1);
- flush_cache_page(vma, address, pte_pfn(orig_pte));
+ flush_cache_page(vma, fe->address, pte_pfn(orig_pte));
entry = pte_mkyoung(orig_pte);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
- if (ptep_set_access_flags(vma, address, page_table, entry, 1))
- update_mmu_cache(vma, address, page_table);
- pte_unmap_unlock(page_table, ptl);
+ if (ptep_set_access_flags(vma, fe->address, fe->pte, entry, 1))
+ update_mmu_cache(vma, fe->address, fe->pte);
+ pte_unmap_unlock(fe->pte, fe->ptl);
if (dirty_shared) {
struct address_space *mapping;
* held to the old page, as well as updating the rmap.
* - In any case, unlock the PTL and drop the reference we took to the old page.
*/
-static int wp_page_copy(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pte_t *page_table, pmd_t *pmd,
- pte_t orig_pte, struct page *old_page)
+static int wp_page_copy(struct fault_env *fe, pte_t orig_pte,
+ struct page *old_page)
{
+ struct vm_area_struct *vma = fe->vma;
+ struct mm_struct *mm = vma->vm_mm;
struct page *new_page = NULL;
- spinlock_t *ptl = NULL;
pte_t entry;
int page_copied = 0;
- const unsigned long mmun_start = address & PAGE_MASK; /* For mmu_notifiers */
- const unsigned long mmun_end = mmun_start + PAGE_SIZE; /* For mmu_notifiers */
+ const unsigned long mmun_start = fe->address & PAGE_MASK;
+ const unsigned long mmun_end = mmun_start + PAGE_SIZE;
struct mem_cgroup *memcg;
if (unlikely(anon_vma_prepare(vma)))
goto oom;
if (is_zero_pfn(pte_pfn(orig_pte))) {
- new_page = alloc_zeroed_user_highpage_movable(vma, address);
+ new_page = alloc_zeroed_user_highpage_movable(vma, fe->address);
if (!new_page)
goto oom;
} else {
- new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
+ new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma,
+ fe->address);
if (!new_page)
goto oom;
- cow_user_page(new_page, old_page, address, vma);
+ cow_user_page(new_page, old_page, fe->address, vma);
}
if (mem_cgroup_try_charge(new_page, mm, GFP_KERNEL, &memcg, false))
/*
* Re-check the pte - we dropped the lock
*/
- page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
- if (likely(pte_same(*page_table, orig_pte))) {
+ fe->pte = pte_offset_map_lock(mm, fe->pmd, fe->address, &fe->ptl);
+ if (likely(pte_same(*fe->pte, orig_pte))) {
if (old_page) {
if (!PageAnon(old_page)) {
dec_mm_counter_fast(mm,
} else {
inc_mm_counter_fast(mm, MM_ANONPAGES);
}
- flush_cache_page(vma, address, pte_pfn(orig_pte));
+ flush_cache_page(vma, fe->address, pte_pfn(orig_pte));
entry = mk_pte(new_page, vma->vm_page_prot);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
/*
* seen in the presence of one thread doing SMC and another
* thread doing COW.
*/
- ptep_clear_flush_notify(vma, address, page_table);
- page_add_new_anon_rmap(new_page, vma, address, false);
+ ptep_clear_flush_notify(vma, fe->address, fe->pte);
+ page_add_new_anon_rmap(new_page, vma, fe->address, false);
mem_cgroup_commit_charge(new_page, memcg, false, false);
lru_cache_add_active_or_unevictable(new_page, vma);
/*
* mmu page tables (such as kvm shadow page tables), we want the
* new page to be mapped directly into the secondary page table.
*/
- set_pte_at_notify(mm, address, page_table, entry);
- update_mmu_cache(vma, address, page_table);
+ set_pte_at_notify(mm, fe->address, fe->pte, entry);
+ update_mmu_cache(vma, fe->address, fe->pte);
if (old_page) {
/*
* Only after switching the pte to the new page may
if (new_page)
put_page(new_page);
- pte_unmap_unlock(page_table, ptl);
+ pte_unmap_unlock(fe->pte, fe->ptl);
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
if (old_page) {
/*
* Handle write page faults for VM_MIXEDMAP or VM_PFNMAP for a VM_SHARED
* mapping
*/
-static int wp_pfn_shared(struct mm_struct *mm,
- struct vm_area_struct *vma, unsigned long address,
- pte_t *page_table, spinlock_t *ptl, pte_t orig_pte,
- pmd_t *pmd)
+static int wp_pfn_shared(struct fault_env *fe, pte_t orig_pte)
{
+ struct vm_area_struct *vma = fe->vma;
+
if (vma->vm_ops && vma->vm_ops->pfn_mkwrite) {
struct vm_fault vmf = {
.page = NULL,
- .pgoff = linear_page_index(vma, address),
- .virtual_address = (void __user *)(address & PAGE_MASK),
+ .pgoff = linear_page_index(vma, fe->address),
+ .virtual_address =
+ (void __user *)(fe->address & PAGE_MASK),
.flags = FAULT_FLAG_WRITE | FAULT_FLAG_MKWRITE,
};
int ret;
- pte_unmap_unlock(page_table, ptl);
+ pte_unmap_unlock(fe->pte, fe->ptl);
ret = vma->vm_ops->pfn_mkwrite(vma, &vmf);
if (ret & VM_FAULT_ERROR)
return ret;
- page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
+ fe->pte = pte_offset_map_lock(vma->vm_mm, fe->pmd, fe->address,
+ &fe->ptl);
/*
* We might have raced with another page fault while we
* released the pte_offset_map_lock.
*/
- if (!pte_same(*page_table, orig_pte)) {
- pte_unmap_unlock(page_table, ptl);
+ if (!pte_same(*fe->pte, orig_pte)) {
+ pte_unmap_unlock(fe->pte, fe->ptl);
return 0;
}
}
- return wp_page_reuse(mm, vma, address, page_table, ptl, orig_pte,
- NULL, 0, 0);
+ return wp_page_reuse(fe, orig_pte, NULL, 0, 0);
}
-static int wp_page_shared(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pte_t *page_table,
- pmd_t *pmd, spinlock_t *ptl, pte_t orig_pte,
- struct page *old_page)
- __releases(ptl)
+static int wp_page_shared(struct fault_env *fe, pte_t orig_pte,
+ struct page *old_page)
+ __releases(fe->ptl)
{
+ struct vm_area_struct *vma = fe->vma;
int page_mkwrite = 0;
get_page(old_page);
if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
int tmp;
- pte_unmap_unlock(page_table, ptl);
- tmp = do_page_mkwrite(vma, old_page, address);
+ pte_unmap_unlock(fe->pte, fe->ptl);
+ tmp = do_page_mkwrite(vma, old_page, fe->address);
if (unlikely(!tmp || (tmp &
(VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
put_page(old_page);
* they did, we just return, as we can count on the
* MMU to tell us if they didn't also make it writable.
*/
- page_table = pte_offset_map_lock(mm, pmd, address,
- &ptl);
- if (!pte_same(*page_table, orig_pte)) {
+ fe->pte = pte_offset_map_lock(vma->vm_mm, fe->pmd, fe->address,
+ &fe->ptl);
+ if (!pte_same(*fe->pte, orig_pte)) {
unlock_page(old_page);
- pte_unmap_unlock(page_table, ptl);
+ pte_unmap_unlock(fe->pte, fe->ptl);
put_page(old_page);
return 0;
}
page_mkwrite = 1;
}
- return wp_page_reuse(mm, vma, address, page_table, ptl,
- orig_pte, old_page, page_mkwrite, 1);
+ return wp_page_reuse(fe, orig_pte, old_page, page_mkwrite, 1);
}
/*
* but allow concurrent faults), with pte both mapped and locked.
* We return with mmap_sem still held, but pte unmapped and unlocked.
*/
-static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pte_t *page_table, pmd_t *pmd,
- spinlock_t *ptl, pte_t orig_pte)
- __releases(ptl)
+static int do_wp_page(struct fault_env *fe, pte_t orig_pte)
+ __releases(fe->ptl)
{
+ struct vm_area_struct *vma = fe->vma;
struct page *old_page;
- old_page = vm_normal_page(vma, address, orig_pte);
+ old_page = vm_normal_page(vma, fe->address, orig_pte);
if (!old_page) {
/*
* VM_MIXEDMAP !pfn_valid() case, or VM_SOFTDIRTY clear on a
*/
if ((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
(VM_WRITE|VM_SHARED))
- return wp_pfn_shared(mm, vma, address, page_table, ptl,
- orig_pte, pmd);
+ return wp_pfn_shared(fe, orig_pte);
- pte_unmap_unlock(page_table, ptl);
- return wp_page_copy(mm, vma, address, page_table, pmd,
- orig_pte, old_page);
+ pte_unmap_unlock(fe->pte, fe->ptl);
+ return wp_page_copy(fe, orig_pte, old_page);
}
/*
int total_mapcount;
if (!trylock_page(old_page)) {
get_page(old_page);
- pte_unmap_unlock(page_table, ptl);
+ pte_unmap_unlock(fe->pte, fe->ptl);
lock_page(old_page);
- page_table = pte_offset_map_lock(mm, pmd, address,
- &ptl);
- if (!pte_same(*page_table, orig_pte)) {
+ fe->pte = pte_offset_map_lock(vma->vm_mm, fe->pmd,
+ fe->address, &fe->ptl);
+ if (!pte_same(*fe->pte, orig_pte)) {
unlock_page(old_page);
- pte_unmap_unlock(page_table, ptl);
+ pte_unmap_unlock(fe->pte, fe->ptl);
put_page(old_page);
return 0;
}
page_move_anon_rmap(old_page, vma);
}
unlock_page(old_page);
- return wp_page_reuse(mm, vma, address, page_table, ptl,
- orig_pte, old_page, 0, 0);
+ return wp_page_reuse(fe, orig_pte, old_page, 0, 0);
}
unlock_page(old_page);
} else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
(VM_WRITE|VM_SHARED))) {
- return wp_page_shared(mm, vma, address, page_table, pmd,
- ptl, orig_pte, old_page);
+ return wp_page_shared(fe, orig_pte, old_page);
}
/*
*/
get_page(old_page);
- pte_unmap_unlock(page_table, ptl);
- return wp_page_copy(mm, vma, address, page_table, pmd,
- orig_pte, old_page);
+ pte_unmap_unlock(fe->pte, fe->ptl);
+ return wp_page_copy(fe, orig_pte, old_page);
}
static void unmap_mapping_range_vma(struct vm_area_struct *vma,
* We return with the mmap_sem locked or unlocked in the same cases
* as does filemap_fault().
*/
-static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pte_t *page_table, pmd_t *pmd,
- unsigned int flags, pte_t orig_pte)
+int do_swap_page(struct fault_env *fe, pte_t orig_pte)
{
- spinlock_t *ptl;
+ struct vm_area_struct *vma = fe->vma;
struct page *page, *swapcache;
struct mem_cgroup *memcg;
swp_entry_t entry;
int exclusive = 0;
int ret = 0;
- if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
+ if (!pte_unmap_same(vma->vm_mm, fe->pmd, fe->pte, orig_pte))
goto out;
entry = pte_to_swp_entry(orig_pte);
if (unlikely(non_swap_entry(entry))) {
if (is_migration_entry(entry)) {
- migration_entry_wait(mm, pmd, address);
+ migration_entry_wait(vma->vm_mm, fe->pmd, fe->address);
} else if (is_hwpoison_entry(entry)) {
ret = VM_FAULT_HWPOISON;
} else {
- print_bad_pte(vma, address, orig_pte, NULL);
+ print_bad_pte(vma, fe->address, orig_pte, NULL);
ret = VM_FAULT_SIGBUS;
}
goto out;
page = lookup_swap_cache(entry);
if (!page) {
page = swapin_readahead(entry,
- GFP_HIGHUSER_MOVABLE, vma, address);
+ GFP_HIGHUSER_MOVABLE, vma, fe->address);
if (!page) {
/*
* Back out if somebody else faulted in this pte
* while we released the pte lock.
*/
- page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
- if (likely(pte_same(*page_table, orig_pte)))
+ fe->pte = pte_offset_map_lock(vma->vm_mm, fe->pmd,
+ fe->address, &fe->ptl);
+ if (likely(pte_same(*fe->pte, orig_pte)))
ret = VM_FAULT_OOM;
delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
goto unlock;
/* Had to read the page from swap area: Major fault */
ret = VM_FAULT_MAJOR;
count_vm_event(PGMAJFAULT);
- mem_cgroup_count_vm_event(mm, PGMAJFAULT);
+ mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT);
} else if (PageHWPoison(page)) {
/*
* hwpoisoned dirty swapcache pages are kept for killing
}
swapcache = page;
- locked = lock_page_or_retry(page, mm, flags);
+ locked = lock_page_or_retry(page, vma->vm_mm, fe->flags);
delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
if (!locked) {
if (unlikely(!PageSwapCache(page) || page_private(page) != entry.val))
goto out_page;
- page = ksm_might_need_to_copy(page, vma, address);
+ page = ksm_might_need_to_copy(page, vma, fe->address);
if (unlikely(!page)) {
ret = VM_FAULT_OOM;
page = swapcache;
goto out_page;
}
- if (mem_cgroup_try_charge(page, mm, GFP_KERNEL, &memcg, false)) {
+ if (mem_cgroup_try_charge(page, vma->vm_mm, GFP_KERNEL,
+ &memcg, false)) {
ret = VM_FAULT_OOM;
goto out_page;
}
/*
* Back out if somebody else already faulted in this pte.
*/
- page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
- if (unlikely(!pte_same(*page_table, orig_pte)))
+ fe->pte = pte_offset_map_lock(vma->vm_mm, fe->pmd, fe->address,
+ &fe->ptl);
+ if (unlikely(!pte_same(*fe->pte, orig_pte)))
goto out_nomap;
if (unlikely(!PageUptodate(page))) {
* must be called after the swap_free(), or it will never succeed.
*/
- inc_mm_counter_fast(mm, MM_ANONPAGES);
- dec_mm_counter_fast(mm, MM_SWAPENTS);
+ inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES);
+ dec_mm_counter_fast(vma->vm_mm, MM_SWAPENTS);
pte = mk_pte(page, vma->vm_page_prot);
- if ((flags & FAULT_FLAG_WRITE) && reuse_swap_page(page, NULL)) {
+ if ((fe->flags & FAULT_FLAG_WRITE) && reuse_swap_page(page, NULL)) {
pte = maybe_mkwrite(pte_mkdirty(pte), vma);
- flags &= ~FAULT_FLAG_WRITE;
+ fe->flags &= ~FAULT_FLAG_WRITE;
ret |= VM_FAULT_WRITE;
exclusive = RMAP_EXCLUSIVE;
}
flush_icache_page(vma, page);
if (pte_swp_soft_dirty(orig_pte))
pte = pte_mksoft_dirty(pte);
- set_pte_at(mm, address, page_table, pte);
+ set_pte_at(vma->vm_mm, fe->address, fe->pte, pte);
if (page == swapcache) {
- do_page_add_anon_rmap(page, vma, address, exclusive);
+ do_page_add_anon_rmap(page, vma, fe->address, exclusive);
mem_cgroup_commit_charge(page, memcg, true, false);
+ activate_page(page);
} else { /* ksm created a completely new copy */
- page_add_new_anon_rmap(page, vma, address, false);
+ page_add_new_anon_rmap(page, vma, fe->address, false);
mem_cgroup_commit_charge(page, memcg, false, false);
lru_cache_add_active_or_unevictable(page, vma);
}
put_page(swapcache);
}
- if (flags & FAULT_FLAG_WRITE) {
- ret |= do_wp_page(mm, vma, address, page_table, pmd, ptl, pte);
+ if (fe->flags & FAULT_FLAG_WRITE) {
+ ret |= do_wp_page(fe, pte);
if (ret & VM_FAULT_ERROR)
ret &= VM_FAULT_ERROR;
goto out;
}
/* No need to invalidate - it was non-present before */
- update_mmu_cache(vma, address, page_table);
+ update_mmu_cache(vma, fe->address, fe->pte);
unlock:
- pte_unmap_unlock(page_table, ptl);
+ pte_unmap_unlock(fe->pte, fe->ptl);
out:
return ret;
out_nomap:
mem_cgroup_cancel_charge(page, memcg, false);
- pte_unmap_unlock(page_table, ptl);
+ pte_unmap_unlock(fe->pte, fe->ptl);
out_page:
unlock_page(page);
out_release:
* but allow concurrent faults), and pte mapped but not yet locked.
* We return with mmap_sem still held, but pte unmapped and unlocked.
*/
-static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pte_t *page_table, pmd_t *pmd,
- unsigned int flags)
+static int do_anonymous_page(struct fault_env *fe)
{
+ struct vm_area_struct *vma = fe->vma;
struct mem_cgroup *memcg;
struct page *page;
- spinlock_t *ptl;
pte_t entry;
- pte_unmap(page_table);
-
/* File mapping without ->vm_ops ? */
if (vma->vm_flags & VM_SHARED)
return VM_FAULT_SIGBUS;
/* Check if we need to add a guard page to the stack */
- if (check_stack_guard_page(vma, address) < 0)
+ if (check_stack_guard_page(vma, fe->address) < 0)
return VM_FAULT_SIGSEGV;
+ /*
+ * Use pte_alloc() instead of pte_alloc_map(). We can't run
+ * pte_offset_map() on pmds where a huge pmd might be created
+ * from a different thread.
+ *
+ * pte_alloc_map() is safe to use under down_write(mmap_sem) or when
+ * parallel threads are excluded by other means.
+ *
+ * Here we only have down_read(mmap_sem).
+ */
+ if (pte_alloc(vma->vm_mm, fe->pmd, fe->address))
+ return VM_FAULT_OOM;
+
+ /* See the comment in pte_alloc_one_map() */
+ if (unlikely(pmd_trans_unstable(fe->pmd)))
+ return 0;
+
/* Use the zero-page for reads */
- if (!(flags & FAULT_FLAG_WRITE) && !mm_forbids_zeropage(mm)) {
- entry = pte_mkspecial(pfn_pte(my_zero_pfn(address),
+ if (!(fe->flags & FAULT_FLAG_WRITE) &&
+ !mm_forbids_zeropage(vma->vm_mm)) {
+ entry = pte_mkspecial(pfn_pte(my_zero_pfn(fe->address),
vma->vm_page_prot));
- page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
- if (!pte_none(*page_table))
+ fe->pte = pte_offset_map_lock(vma->vm_mm, fe->pmd, fe->address,
+ &fe->ptl);
+ if (!pte_none(*fe->pte))
goto unlock;
/* Deliver the page fault to userland, check inside PT lock */
if (userfaultfd_missing(vma)) {
- pte_unmap_unlock(page_table, ptl);
- return handle_userfault(vma, address, flags,
- VM_UFFD_MISSING);
+ pte_unmap_unlock(fe->pte, fe->ptl);
+ return handle_userfault(fe, VM_UFFD_MISSING);
}
goto setpte;
}
/* Allocate our own private page. */
if (unlikely(anon_vma_prepare(vma)))
goto oom;
- page = alloc_zeroed_user_highpage_movable(vma, address);
+ page = alloc_zeroed_user_highpage_movable(vma, fe->address);
if (!page)
goto oom;
- if (mem_cgroup_try_charge(page, mm, GFP_KERNEL, &memcg, false))
+ if (mem_cgroup_try_charge(page, vma->vm_mm, GFP_KERNEL, &memcg, false))
goto oom_free_page;
/*
if (vma->vm_flags & VM_WRITE)
entry = pte_mkwrite(pte_mkdirty(entry));
- page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
- if (!pte_none(*page_table))
+ fe->pte = pte_offset_map_lock(vma->vm_mm, fe->pmd, fe->address,
+ &fe->ptl);
+ if (!pte_none(*fe->pte))
goto release;
/* Deliver the page fault to userland, check inside PT lock */
if (userfaultfd_missing(vma)) {
- pte_unmap_unlock(page_table, ptl);
+ pte_unmap_unlock(fe->pte, fe->ptl);
mem_cgroup_cancel_charge(page, memcg, false);
put_page(page);
- return handle_userfault(vma, address, flags,
- VM_UFFD_MISSING);
+ return handle_userfault(fe, VM_UFFD_MISSING);
}
- inc_mm_counter_fast(mm, MM_ANONPAGES);
- page_add_new_anon_rmap(page, vma, address, false);
+ inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES);
+ page_add_new_anon_rmap(page, vma, fe->address, false);
mem_cgroup_commit_charge(page, memcg, false, false);
lru_cache_add_active_or_unevictable(page, vma);
setpte:
- set_pte_at(mm, address, page_table, entry);
+ set_pte_at(vma->vm_mm, fe->address, fe->pte, entry);
/* No need to invalidate - it was non-present before */
- update_mmu_cache(vma, address, page_table);
+ update_mmu_cache(vma, fe->address, fe->pte);
unlock:
- pte_unmap_unlock(page_table, ptl);
+ pte_unmap_unlock(fe->pte, fe->ptl);
return 0;
release:
mem_cgroup_cancel_charge(page, memcg, false);
* released depending on flags and vma->vm_ops->fault() return value.
* See filemap_fault() and __lock_page_retry().
*/
-static int __do_fault(struct vm_area_struct *vma, unsigned long address,
- pgoff_t pgoff, unsigned int flags,
- struct page *cow_page, struct page **page,
- void **entry)
+static int __do_fault(struct fault_env *fe, pgoff_t pgoff,
+ struct page *cow_page, struct page **page, void **entry)
{
+ struct vm_area_struct *vma = fe->vma;
struct vm_fault vmf;
int ret;
- vmf.virtual_address = (void __user *)(address & PAGE_MASK);
+ vmf.virtual_address = (void __user *)(fe->address & PAGE_MASK);
vmf.pgoff = pgoff;
- vmf.flags = flags;
+ vmf.flags = fe->flags;
vmf.page = NULL;
vmf.gfp_mask = __get_fault_gfp_mask(vma);
vmf.cow_page = cow_page;
return ret;
}
+static int pte_alloc_one_map(struct fault_env *fe)
+{
+ struct vm_area_struct *vma = fe->vma;
+
+ if (!pmd_none(*fe->pmd))
+ goto map_pte;
+ if (fe->prealloc_pte) {
+ fe->ptl = pmd_lock(vma->vm_mm, fe->pmd);
+ if (unlikely(!pmd_none(*fe->pmd))) {
+ spin_unlock(fe->ptl);
+ goto map_pte;
+ }
+
+ atomic_long_inc(&vma->vm_mm->nr_ptes);
+ pmd_populate(vma->vm_mm, fe->pmd, fe->prealloc_pte);
+ spin_unlock(fe->ptl);
+ fe->prealloc_pte = 0;
+ } else if (unlikely(pte_alloc(vma->vm_mm, fe->pmd, fe->address))) {
+ return VM_FAULT_OOM;
+ }
+map_pte:
+ /*
+ * If a huge pmd materialized under us just retry later. Use
+ * pmd_trans_unstable() instead of pmd_trans_huge() to ensure the pmd
+ * didn't become pmd_trans_huge under us and then back to pmd_none, as
+ * a result of MADV_DONTNEED running immediately after a huge pmd fault
+ * in a different thread of this mm, in turn leading to a misleading
+ * pmd_trans_huge() retval. All we have to ensure is that it is a
+ * regular pmd that we can walk with pte_offset_map() and we can do that
+ * through an atomic read in C, which is what pmd_trans_unstable()
+ * provides.
+ */
+ if (pmd_trans_unstable(fe->pmd) || pmd_devmap(*fe->pmd))
+ return VM_FAULT_NOPAGE;
+
+ fe->pte = pte_offset_map_lock(vma->vm_mm, fe->pmd, fe->address,
+ &fe->ptl);
+ return 0;
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
+
+#define HPAGE_CACHE_INDEX_MASK (HPAGE_PMD_NR - 1)
+static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
+ unsigned long haddr)
+{
+ if (((vma->vm_start >> PAGE_SHIFT) & HPAGE_CACHE_INDEX_MASK) !=
+ (vma->vm_pgoff & HPAGE_CACHE_INDEX_MASK))
+ return false;
+ if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end)
+ return false;
+ return true;
+}
+
+static int do_set_pmd(struct fault_env *fe, struct page *page)
+{
+ struct vm_area_struct *vma = fe->vma;
+ bool write = fe->flags & FAULT_FLAG_WRITE;
+ unsigned long haddr = fe->address & HPAGE_PMD_MASK;
+ pmd_t entry;
+ int i, ret;
+
+ if (!transhuge_vma_suitable(vma, haddr))
+ return VM_FAULT_FALLBACK;
+
+ ret = VM_FAULT_FALLBACK;
+ page = compound_head(page);
+
+ fe->ptl = pmd_lock(vma->vm_mm, fe->pmd);
+ if (unlikely(!pmd_none(*fe->pmd)))
+ goto out;
+
+ for (i = 0; i < HPAGE_PMD_NR; i++)
+ flush_icache_page(vma, page + i);
+
+ entry = mk_huge_pmd(page, vma->vm_page_prot);
+ if (write)
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
+
+ add_mm_counter(vma->vm_mm, MM_FILEPAGES, HPAGE_PMD_NR);
+ page_add_file_rmap(page, true);
+
+ set_pmd_at(vma->vm_mm, haddr, fe->pmd, entry);
+
+ update_mmu_cache_pmd(vma, haddr, fe->pmd);
+
+ /* fault is handled */
+ ret = 0;
+ count_vm_event(THP_FILE_MAPPED);
+out:
+ spin_unlock(fe->ptl);
+ return ret;
+}
+#else
+static int do_set_pmd(struct fault_env *fe, struct page *page)
+{
+ BUILD_BUG();
+ return 0;
+}
+#endif
+
/**
- * do_set_pte - setup new PTE entry for given page and add reverse page mapping.
+ * alloc_set_pte - setup new PTE entry for given page and add reverse page
+ * mapping. If needed, the fucntion allocates page table or use pre-allocated.
*
- * @vma: virtual memory area
- * @address: user virtual address
+ * @fe: fault environment
+ * @memcg: memcg to charge page (only for private mappings)
* @page: page to map
- * @pte: pointer to target page table entry
- * @write: true, if new entry is writable
- * @anon: true, if it's anonymous page
*
- * Caller must hold page table lock relevant for @pte.
+ * Caller must take care of unlocking fe->ptl, if fe->pte is non-NULL on return.
*
* Target users are page handler itself and implementations of
* vm_ops->map_pages.
*/
-void do_set_pte(struct vm_area_struct *vma, unsigned long address,
- struct page *page, pte_t *pte, bool write, bool anon)
+int alloc_set_pte(struct fault_env *fe, struct mem_cgroup *memcg,
+ struct page *page)
{
+ struct vm_area_struct *vma = fe->vma;
+ bool write = fe->flags & FAULT_FLAG_WRITE;
pte_t entry;
+ int ret;
+
+ if (pmd_none(*fe->pmd) && PageTransCompound(page) &&
+ IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) {
+ /* THP on COW? */
+ VM_BUG_ON_PAGE(memcg, page);
+
+ ret = do_set_pmd(fe, page);
+ if (ret != VM_FAULT_FALLBACK)
+ return ret;
+ }
+
+ if (!fe->pte) {
+ ret = pte_alloc_one_map(fe);
+ if (ret)
+ return ret;
+ }
+
+ /* Re-check under ptl */
+ if (unlikely(!pte_none(*fe->pte)))
+ return VM_FAULT_NOPAGE;
flush_icache_page(vma, page);
entry = mk_pte(page, vma->vm_page_prot);
if (write)
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
- if (anon) {
+ /* copy-on-write page */
+ if (write && !(vma->vm_flags & VM_SHARED)) {
inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES);
- page_add_new_anon_rmap(page, vma, address, false);
+ page_add_new_anon_rmap(page, vma, fe->address, false);
+ mem_cgroup_commit_charge(page, memcg, false, false);
+ lru_cache_add_active_or_unevictable(page, vma);
} else {
inc_mm_counter_fast(vma->vm_mm, mm_counter_file(page));
- page_add_file_rmap(page);
+ page_add_file_rmap(page, false);
}
- set_pte_at(vma->vm_mm, address, pte, entry);
+ set_pte_at(vma->vm_mm, fe->address, fe->pte, entry);
/* no need to invalidate: a not-present page won't be cached */
- update_mmu_cache(vma, address, pte);
+ update_mmu_cache(vma, fe->address, fe->pte);
+
+ return 0;
}
static unsigned long fault_around_bytes __read_mostly =
* fault_around_pages() value (and therefore to page order). This way it's
* easier to guarantee that we don't cross page table boundaries.
*/
-static void do_fault_around(struct vm_area_struct *vma, unsigned long address,
- pte_t *pte, pgoff_t pgoff, unsigned int flags)
+static int do_fault_around(struct fault_env *fe, pgoff_t start_pgoff)
{
- unsigned long start_addr, nr_pages, mask;
- pgoff_t max_pgoff;
- struct vm_fault vmf;
- int off;
+ unsigned long address = fe->address, nr_pages, mask;
+ pgoff_t end_pgoff;
+ int off, ret = 0;
nr_pages = READ_ONCE(fault_around_bytes) >> PAGE_SHIFT;
mask = ~(nr_pages * PAGE_SIZE - 1) & PAGE_MASK;
- start_addr = max(address & mask, vma->vm_start);
- off = ((address - start_addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
- pte -= off;
- pgoff -= off;
+ fe->address = max(address & mask, fe->vma->vm_start);
+ off = ((address - fe->address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
+ start_pgoff -= off;
/*
- * max_pgoff is either end of page table or end of vma
- * or fault_around_pages() from pgoff, depending what is nearest.
+ * end_pgoff is either end of page table or end of vma
+ * or fault_around_pages() from start_pgoff, depending what is nearest.
*/
- max_pgoff = pgoff - ((start_addr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +
+ end_pgoff = start_pgoff -
+ ((fe->address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +
PTRS_PER_PTE - 1;
- max_pgoff = min3(max_pgoff, vma_pages(vma) + vma->vm_pgoff - 1,
- pgoff + nr_pages - 1);
+ end_pgoff = min3(end_pgoff, vma_pages(fe->vma) + fe->vma->vm_pgoff - 1,
+ start_pgoff + nr_pages - 1);
- /* Check if it makes any sense to call ->map_pages */
- while (!pte_none(*pte)) {
- if (++pgoff > max_pgoff)
- return;
- start_addr += PAGE_SIZE;
- if (start_addr >= vma->vm_end)
- return;
- pte++;
+ if (pmd_none(*fe->pmd)) {
+ fe->prealloc_pte = pte_alloc_one(fe->vma->vm_mm, fe->address);
+ if (!fe->prealloc_pte)
+ goto out;
+ smp_wmb(); /* See comment in __pte_alloc() */
}
- vmf.virtual_address = (void __user *) start_addr;
- vmf.pte = pte;
- vmf.pgoff = pgoff;
- vmf.max_pgoff = max_pgoff;
- vmf.flags = flags;
- vmf.gfp_mask = __get_fault_gfp_mask(vma);
- vma->vm_ops->map_pages(vma, &vmf);
+ fe->vma->vm_ops->map_pages(fe, start_pgoff, end_pgoff);
+
+ /* preallocated pagetable is unused: free it */
+ if (fe->prealloc_pte) {
+ pte_free(fe->vma->vm_mm, fe->prealloc_pte);
+ fe->prealloc_pte = 0;
+ }
+ /* Huge page is mapped? Page fault is solved */
+ if (pmd_trans_huge(*fe->pmd)) {
+ ret = VM_FAULT_NOPAGE;
+ goto out;
+ }
+
+ /* ->map_pages() haven't done anything useful. Cold page cache? */
+ if (!fe->pte)
+ goto out;
+
+ /* check if the page fault is solved */
+ fe->pte -= (fe->address >> PAGE_SHIFT) - (address >> PAGE_SHIFT);
+ if (!pte_none(*fe->pte))
+ ret = VM_FAULT_NOPAGE;
+ pte_unmap_unlock(fe->pte, fe->ptl);
+out:
+ fe->address = address;
+ fe->pte = NULL;
+ return ret;
}
-static int do_read_fault(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmd,
- pgoff_t pgoff, unsigned int flags, pte_t orig_pte)
+static int do_read_fault(struct fault_env *fe, pgoff_t pgoff)
{
+ struct vm_area_struct *vma = fe->vma;
struct page *fault_page;
- spinlock_t *ptl;
- pte_t *pte;
int ret = 0;
/*
* something).
*/
if (vma->vm_ops->map_pages && fault_around_bytes >> PAGE_SHIFT > 1) {
- pte = pte_offset_map_lock(mm, pmd, address, &ptl);
- do_fault_around(vma, address, pte, pgoff, flags);
- if (!pte_same(*pte, orig_pte))
- goto unlock_out;
- pte_unmap_unlock(pte, ptl);
+ ret = do_fault_around(fe, pgoff);
+ if (ret)
+ return ret;
}
- ret = __do_fault(vma, address, pgoff, flags, NULL, &fault_page, NULL);
+ ret = __do_fault(fe, pgoff, NULL, &fault_page, NULL);
if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))
return ret;
- pte = pte_offset_map_lock(mm, pmd, address, &ptl);
- if (unlikely(!pte_same(*pte, orig_pte))) {
- pte_unmap_unlock(pte, ptl);
- unlock_page(fault_page);
- put_page(fault_page);
- return ret;
- }
- do_set_pte(vma, address, fault_page, pte, false, false);
+ ret |= alloc_set_pte(fe, NULL, fault_page);
+ if (fe->pte)
+ pte_unmap_unlock(fe->pte, fe->ptl);
unlock_page(fault_page);
-unlock_out:
- pte_unmap_unlock(pte, ptl);
+ if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))
+ put_page(fault_page);
return ret;
}
-static int do_cow_fault(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmd,
- pgoff_t pgoff, unsigned int flags, pte_t orig_pte)
+static int do_cow_fault(struct fault_env *fe, pgoff_t pgoff)
{
+ struct vm_area_struct *vma = fe->vma;
struct page *fault_page, *new_page;
void *fault_entry;
struct mem_cgroup *memcg;
- spinlock_t *ptl;
- pte_t *pte;
int ret;
if (unlikely(anon_vma_prepare(vma)))
return VM_FAULT_OOM;
- new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
+ new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, fe->address);
if (!new_page)
return VM_FAULT_OOM;
- if (mem_cgroup_try_charge(new_page, mm, GFP_KERNEL, &memcg, false)) {
+ if (mem_cgroup_try_charge(new_page, vma->vm_mm, GFP_KERNEL,
+ &memcg, false)) {
put_page(new_page);
return VM_FAULT_OOM;
}
- ret = __do_fault(vma, address, pgoff, flags, new_page, &fault_page,
- &fault_entry);
+ ret = __do_fault(fe, pgoff, new_page, &fault_page, &fault_entry);
if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))
goto uncharge_out;
if (!(ret & VM_FAULT_DAX_LOCKED))
- copy_user_highpage(new_page, fault_page, address, vma);
+ copy_user_highpage(new_page, fault_page, fe->address, vma);
__SetPageUptodate(new_page);
- pte = pte_offset_map_lock(mm, pmd, address, &ptl);
- if (unlikely(!pte_same(*pte, orig_pte))) {
- pte_unmap_unlock(pte, ptl);
- if (!(ret & VM_FAULT_DAX_LOCKED)) {
- unlock_page(fault_page);
- put_page(fault_page);
- } else {
- dax_unlock_mapping_entry(vma->vm_file->f_mapping,
- pgoff);
- }
- goto uncharge_out;
- }
- do_set_pte(vma, address, new_page, pte, true, true);
- mem_cgroup_commit_charge(new_page, memcg, false, false);
- lru_cache_add_active_or_unevictable(new_page, vma);
- pte_unmap_unlock(pte, ptl);
+ ret |= alloc_set_pte(fe, memcg, new_page);
+ if (fe->pte)
+ pte_unmap_unlock(fe->pte, fe->ptl);
if (!(ret & VM_FAULT_DAX_LOCKED)) {
unlock_page(fault_page);
put_page(fault_page);
} else {
dax_unlock_mapping_entry(vma->vm_file->f_mapping, pgoff);
}
+ if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))
+ goto uncharge_out;
return ret;
uncharge_out:
mem_cgroup_cancel_charge(new_page, memcg, false);
return ret;
}
-static int do_shared_fault(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmd,
- pgoff_t pgoff, unsigned int flags, pte_t orig_pte)
+static int do_shared_fault(struct fault_env *fe, pgoff_t pgoff)
{
+ struct vm_area_struct *vma = fe->vma;
struct page *fault_page;
struct address_space *mapping;
- spinlock_t *ptl;
- pte_t *pte;
int dirtied = 0;
int ret, tmp;
- ret = __do_fault(vma, address, pgoff, flags, NULL, &fault_page, NULL);
+ ret = __do_fault(fe, pgoff, NULL, &fault_page, NULL);
if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))
return ret;
*/
if (vma->vm_ops->page_mkwrite) {
unlock_page(fault_page);
- tmp = do_page_mkwrite(vma, fault_page, address);
+ tmp = do_page_mkwrite(vma, fault_page, fe->address);
if (unlikely(!tmp ||
(tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
put_page(fault_page);
}
}
- pte = pte_offset_map_lock(mm, pmd, address, &ptl);
- if (unlikely(!pte_same(*pte, orig_pte))) {
- pte_unmap_unlock(pte, ptl);
+ ret |= alloc_set_pte(fe, NULL, fault_page);
+ if (fe->pte)
+ pte_unmap_unlock(fe->pte, fe->ptl);
+ if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE |
+ VM_FAULT_RETRY))) {
unlock_page(fault_page);
put_page(fault_page);
return ret;
}
- do_set_pte(vma, address, fault_page, pte, true, false);
- pte_unmap_unlock(pte, ptl);
if (set_page_dirty(fault_page))
dirtied = 1;
* The mmap_sem may have been released depending on flags and our
* return value. See filemap_fault() and __lock_page_or_retry().
*/
-static int do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pte_t *page_table, pmd_t *pmd,
- unsigned int flags, pte_t orig_pte)
+static int do_fault(struct fault_env *fe)
{
- pgoff_t pgoff = linear_page_index(vma, address);
+ struct vm_area_struct *vma = fe->vma;
+ pgoff_t pgoff = linear_page_index(vma, fe->address);
- pte_unmap(page_table);
/* The VMA was not fully populated on mmap() or missing VM_DONTEXPAND */
if (!vma->vm_ops->fault)
return VM_FAULT_SIGBUS;
- if (!(flags & FAULT_FLAG_WRITE))
- return do_read_fault(mm, vma, address, pmd, pgoff, flags,
- orig_pte);
+ if (!(fe->flags & FAULT_FLAG_WRITE))
+ return do_read_fault(fe, pgoff);
if (!(vma->vm_flags & VM_SHARED))
- return do_cow_fault(mm, vma, address, pmd, pgoff, flags,
- orig_pte);
- return do_shared_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
+ return do_cow_fault(fe, pgoff);
+ return do_shared_fault(fe, pgoff);
}
static int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
return mpol_misplaced(page, vma, addr);
}
-static int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long addr, pte_t pte, pte_t *ptep, pmd_t *pmd)
+static int do_numa_page(struct fault_env *fe, pte_t pte)
{
+ struct vm_area_struct *vma = fe->vma;
struct page *page = NULL;
- spinlock_t *ptl;
int page_nid = -1;
int last_cpupid;
int target_nid;
* page table entry is not accessible, so there would be no
* concurrent hardware modifications to the PTE.
*/
- ptl = pte_lockptr(mm, pmd);
- spin_lock(ptl);
- if (unlikely(!pte_same(*ptep, pte))) {
- pte_unmap_unlock(ptep, ptl);
+ fe->ptl = pte_lockptr(vma->vm_mm, fe->pmd);
+ spin_lock(fe->ptl);
+ if (unlikely(!pte_same(*fe->pte, pte))) {
+ pte_unmap_unlock(fe->pte, fe->ptl);
goto out;
}
pte = pte_mkyoung(pte);
if (was_writable)
pte = pte_mkwrite(pte);
- set_pte_at(mm, addr, ptep, pte);
- update_mmu_cache(vma, addr, ptep);
+ set_pte_at(vma->vm_mm, fe->address, fe->pte, pte);
+ update_mmu_cache(vma, fe->address, fe->pte);
- page = vm_normal_page(vma, addr, pte);
+ page = vm_normal_page(vma, fe->address, pte);
if (!page) {
- pte_unmap_unlock(ptep, ptl);
+ pte_unmap_unlock(fe->pte, fe->ptl);
return 0;
}
/* TODO: handle PTE-mapped THP */
if (PageCompound(page)) {
- pte_unmap_unlock(ptep, ptl);
+ pte_unmap_unlock(fe->pte, fe->ptl);
return 0;
}
last_cpupid = page_cpupid_last(page);
page_nid = page_to_nid(page);
- target_nid = numa_migrate_prep(page, vma, addr, page_nid, &flags);
- pte_unmap_unlock(ptep, ptl);
+ target_nid = numa_migrate_prep(page, vma, fe->address, page_nid,
+ &flags);
+ pte_unmap_unlock(fe->pte, fe->ptl);
if (target_nid == -1) {
put_page(page);
goto out;
return 0;
}
-static int create_huge_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmd, unsigned int flags)
+static int create_huge_pmd(struct fault_env *fe)
{
+ struct vm_area_struct *vma = fe->vma;
if (vma_is_anonymous(vma))
- return do_huge_pmd_anonymous_page(mm, vma, address, pmd, flags);
+ return do_huge_pmd_anonymous_page(fe);
if (vma->vm_ops->pmd_fault)
- return vma->vm_ops->pmd_fault(vma, address, pmd, flags);
+ return vma->vm_ops->pmd_fault(vma, fe->address, fe->pmd,
+ fe->flags);
return VM_FAULT_FALLBACK;
}
-static int wp_huge_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pmd_t *pmd, pmd_t orig_pmd,
- unsigned int flags)
+static int wp_huge_pmd(struct fault_env *fe, pmd_t orig_pmd)
{
- if (vma_is_anonymous(vma))
- return do_huge_pmd_wp_page(mm, vma, address, pmd, orig_pmd);
- if (vma->vm_ops->pmd_fault)
- return vma->vm_ops->pmd_fault(vma, address, pmd, flags);
+ if (vma_is_anonymous(fe->vma))
+ return do_huge_pmd_wp_page(fe, orig_pmd);
+ if (fe->vma->vm_ops->pmd_fault)
+ return fe->vma->vm_ops->pmd_fault(fe->vma, fe->address, fe->pmd,
+ fe->flags);
+
+ /* COW handled on pte level: split pmd */
+ VM_BUG_ON_VMA(fe->vma->vm_flags & VM_SHARED, fe->vma);
+ split_huge_pmd(fe->vma, fe->pmd, fe->address);
+
return VM_FAULT_FALLBACK;
}
* with external mmu caches can use to update those (ie the Sparc or
* PowerPC hashed page tables that act as extended TLBs).
*
- * We enter with non-exclusive mmap_sem (to exclude vma changes,
- * but allow concurrent faults), and pte mapped but not yet locked.
- * We return with pte unmapped and unlocked.
+ * We enter with non-exclusive mmap_sem (to exclude vma changes, but allow
+ * concurrent faults).
*
- * The mmap_sem may have been released depending on flags and our
- * return value. See filemap_fault() and __lock_page_or_retry().
+ * The mmap_sem may have been released depending on flags and our return value.
+ * See filemap_fault() and __lock_page_or_retry().
*/
-static int handle_pte_fault(struct mm_struct *mm,
- struct vm_area_struct *vma, unsigned long address,
- pte_t *pte, pmd_t *pmd, unsigned int flags)
+static int handle_pte_fault(struct fault_env *fe)
{
pte_t entry;
- spinlock_t *ptl;
- /*
- * some architectures can have larger ptes than wordsize,
- * e.g.ppc44x-defconfig has CONFIG_PTE_64BIT=y and CONFIG_32BIT=y,
- * so READ_ONCE or ACCESS_ONCE cannot guarantee atomic accesses.
- * The code below just needs a consistent view for the ifs and
- * we later double check anyway with the ptl lock held. So here
- * a barrier will do.
- */
- entry = *pte;
- barrier();
- if (!pte_present(entry)) {
+ if (unlikely(pmd_none(*fe->pmd))) {
+ /*
+ * Leave __pte_alloc() until later: because vm_ops->fault may
+ * want to allocate huge page, and if we expose page table
+ * for an instant, it will be difficult to retract from
+ * concurrent faults and from rmap lookups.
+ */
+ fe->pte = NULL;
+ } else {
+ /* See comment in pte_alloc_one_map() */
+ if (pmd_trans_unstable(fe->pmd) || pmd_devmap(*fe->pmd))
+ return 0;
+ /*
+ * A regular pmd is established and it can't morph into a huge
+ * pmd from under us anymore at this point because we hold the
+ * mmap_sem read mode and khugepaged takes it in write mode.
+ * So now it's safe to run pte_offset_map().
+ */
+ fe->pte = pte_offset_map(fe->pmd, fe->address);
+
+ entry = *fe->pte;
+
+ /*
+ * some architectures can have larger ptes than wordsize,
+ * e.g.ppc44x-defconfig has CONFIG_PTE_64BIT=y and
+ * CONFIG_32BIT=y, so READ_ONCE or ACCESS_ONCE cannot guarantee
+ * atomic accesses. The code below just needs a consistent
+ * view for the ifs and we later double check anyway with the
+ * ptl lock held. So here a barrier will do.
+ */
+ barrier();
if (pte_none(entry)) {
- if (vma_is_anonymous(vma))
- return do_anonymous_page(mm, vma, address,
- pte, pmd, flags);
- else
- return do_fault(mm, vma, address, pte, pmd,
- flags, entry);
+ pte_unmap(fe->pte);
+ fe->pte = NULL;
}
- return do_swap_page(mm, vma, address,
- pte, pmd, flags, entry);
}
+ if (!fe->pte) {
+ if (vma_is_anonymous(fe->vma))
+ return do_anonymous_page(fe);
+ else
+ return do_fault(fe);
+ }
+
+ if (!pte_present(entry))
+ return do_swap_page(fe, entry);
+
if (pte_protnone(entry))
- return do_numa_page(mm, vma, address, entry, pte, pmd);
+ return do_numa_page(fe, entry);
- ptl = pte_lockptr(mm, pmd);
- spin_lock(ptl);
- if (unlikely(!pte_same(*pte, entry)))
+ fe->ptl = pte_lockptr(fe->vma->vm_mm, fe->pmd);
+ spin_lock(fe->ptl);
+ if (unlikely(!pte_same(*fe->pte, entry)))
goto unlock;
- if (flags & FAULT_FLAG_WRITE) {
+ if (fe->flags & FAULT_FLAG_WRITE) {
if (!pte_write(entry))
- return do_wp_page(mm, vma, address,
- pte, pmd, ptl, entry);
+ return do_wp_page(fe, entry);
entry = pte_mkdirty(entry);
}
entry = pte_mkyoung(entry);
- if (ptep_set_access_flags(vma, address, pte, entry, flags & FAULT_FLAG_WRITE)) {
- update_mmu_cache(vma, address, pte);
+ if (ptep_set_access_flags(fe->vma, fe->address, fe->pte, entry,
+ fe->flags & FAULT_FLAG_WRITE)) {
+ update_mmu_cache(fe->vma, fe->address, fe->pte);
} else {
/*
* This is needed only for protection faults but the arch code
* This still avoids useless tlb flushes for .text page faults
* with threads.
*/
- if (flags & FAULT_FLAG_WRITE)
- flush_tlb_fix_spurious_fault(vma, address);
+ if (fe->flags & FAULT_FLAG_WRITE)
+ flush_tlb_fix_spurious_fault(fe->vma, fe->address);
}
unlock:
- pte_unmap_unlock(pte, ptl);
+ pte_unmap_unlock(fe->pte, fe->ptl);
return 0;
}
* The mmap_sem may have been released depending on flags and our
* return value. See filemap_fault() and __lock_page_or_retry().
*/
-static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, unsigned int flags)
+static int __handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
+ unsigned int flags)
{
+ struct fault_env fe = {
+ .vma = vma,
+ .address = address,
+ .flags = flags,
+ };
+ struct mm_struct *mm = vma->vm_mm;
pgd_t *pgd;
pud_t *pud;
- pmd_t *pmd;
- pte_t *pte;
-
- if (!arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE,
- flags & FAULT_FLAG_INSTRUCTION,
- flags & FAULT_FLAG_REMOTE))
- return VM_FAULT_SIGSEGV;
-
- if (unlikely(is_vm_hugetlb_page(vma)))
- return hugetlb_fault(mm, vma, address, flags);
pgd = pgd_offset(mm, address);
pud = pud_alloc(mm, pgd, address);
if (!pud)
return VM_FAULT_OOM;
- pmd = pmd_alloc(mm, pud, address);
- if (!pmd)
+ fe.pmd = pmd_alloc(mm, pud, address);
+ if (!fe.pmd)
return VM_FAULT_OOM;
- if (pmd_none(*pmd) && transparent_hugepage_enabled(vma)) {
- int ret = create_huge_pmd(mm, vma, address, pmd, flags);
+ if (pmd_none(*fe.pmd) && transparent_hugepage_enabled(vma)) {
+ int ret = create_huge_pmd(&fe);
if (!(ret & VM_FAULT_FALLBACK))
return ret;
} else {
- pmd_t orig_pmd = *pmd;
+ pmd_t orig_pmd = *fe.pmd;
int ret;
barrier();
if (pmd_trans_huge(orig_pmd) || pmd_devmap(orig_pmd)) {
- unsigned int dirty = flags & FAULT_FLAG_WRITE;
-
if (pmd_protnone(orig_pmd))
- return do_huge_pmd_numa_page(mm, vma, address,
- orig_pmd, pmd);
+ return do_huge_pmd_numa_page(&fe, orig_pmd);
- if (dirty && !pmd_write(orig_pmd)) {
- ret = wp_huge_pmd(mm, vma, address, pmd,
- orig_pmd, flags);
+ if ((fe.flags & FAULT_FLAG_WRITE) &&
+ !pmd_write(orig_pmd)) {
+ ret = wp_huge_pmd(&fe, orig_pmd);
if (!(ret & VM_FAULT_FALLBACK))
return ret;
} else {
- huge_pmd_set_accessed(mm, vma, address, pmd,
- orig_pmd, dirty);
+ huge_pmd_set_accessed(&fe, orig_pmd);
return 0;
}
}
}
- /*
- * Use pte_alloc() instead of pte_alloc_map, because we can't
- * run pte_offset_map on the pmd, if an huge pmd could
- * materialize from under us from a different thread.
- */
- if (unlikely(pte_alloc(mm, pmd, address)))
- return VM_FAULT_OOM;
- /*
- * If a huge pmd materialized under us just retry later. Use
- * pmd_trans_unstable() instead of pmd_trans_huge() to ensure the pmd
- * didn't become pmd_trans_huge under us and then back to pmd_none, as
- * a result of MADV_DONTNEED running immediately after a huge pmd fault
- * in a different thread of this mm, in turn leading to a misleading
- * pmd_trans_huge() retval. All we have to ensure is that it is a
- * regular pmd that we can walk with pte_offset_map() and we can do that
- * through an atomic read in C, which is what pmd_trans_unstable()
- * provides.
- */
- if (unlikely(pmd_trans_unstable(pmd) || pmd_devmap(*pmd)))
- return 0;
- /*
- * A regular pmd is established and it can't morph into a huge pmd
- * from under us anymore at this point because we hold the mmap_sem
- * read mode and khugepaged takes it in write mode. So now it's
- * safe to run pte_offset_map().
- */
- pte = pte_offset_map(pmd, address);
-
- return handle_pte_fault(mm, vma, address, pte, pmd, flags);
+ return handle_pte_fault(&fe);
}
/*
* The mmap_sem may have been released depending on flags and our
* return value. See filemap_fault() and __lock_page_or_retry().
*/
-int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, unsigned int flags)
+int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
+ unsigned int flags)
{
int ret;
__set_current_state(TASK_RUNNING);
count_vm_event(PGFAULT);
- mem_cgroup_count_vm_event(mm, PGFAULT);
+ mem_cgroup_count_vm_event(vma->vm_mm, PGFAULT);
/* do counter updates before entering really critical section. */
check_sync_rss_stat(current);
if (flags & FAULT_FLAG_USER)
mem_cgroup_oom_enable();
- ret = __handle_mm_fault(mm, vma, address, flags);
+ if (!arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE,
+ flags & FAULT_FLAG_INSTRUCTION,
+ flags & FAULT_FLAG_REMOTE))
+ return VM_FAULT_SIGSEGV;
+
+ if (unlikely(is_vm_hugetlb_page(vma)))
+ ret = hugetlb_fault(vma->vm_mm, vma, address, flags);
+ else
+ ret = __handle_mm_fault(vma, address, flags);
if (flags & FAULT_FLAG_USER) {
mem_cgroup_oom_disable();
projects / cascardo / linux.git / blobdiff