if (!pte_file(pte)) {
swp_entry_t entry = pte_to_swp_entry(pte);
- if (swap_duplicate(entry) < 0)
- return entry.val;
-
- /* make sure dst_mm is on swapoff's mmlist. */
- if (unlikely(list_empty(&dst_mm->mmlist))) {
- spin_lock(&mmlist_lock);
- if (list_empty(&dst_mm->mmlist))
- list_add(&dst_mm->mmlist,
- &src_mm->mmlist);
- spin_unlock(&mmlist_lock);
- }
- if (likely(!non_swap_entry(entry)))
+ if (likely(!non_swap_entry(entry))) {
+ if (swap_duplicate(entry) < 0)
+ return entry.val;
+
+ /* make sure dst_mm is on swapoff's mmlist. */
+ if (unlikely(list_empty(&dst_mm->mmlist))) {
+ spin_lock(&mmlist_lock);
+ if (list_empty(&dst_mm->mmlist))
+ list_add(&dst_mm->mmlist,
+ &src_mm->mmlist);
+ spin_unlock(&mmlist_lock);
+ }
rss[MM_SWAPENTS]++;
- else if (is_migration_entry(entry)) {
+ } else if (is_migration_entry(entry)) {
page = migration_entry_to_page(entry);
if (PageAnon(page))
else
return -EFAULT;
}
- if (ret & VM_FAULT_SIGBUS)
+ if (ret & (VM_FAULT_SIGBUS |
+ VM_FAULT_SIGSEGV))
return i ? i : -EFAULT;
BUG();
}
return -ENOMEM;
if (ret & (VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE))
return -EHWPOISON;
- if (ret & VM_FAULT_SIGBUS)
+ if (ret & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV))
return -EFAULT;
BUG();
}
if (prev && prev->vm_end == address)
return prev->vm_flags & VM_GROWSDOWN ? 0 : -ENOMEM;
- expand_downwards(vma, address - PAGE_SIZE);
+ return expand_downwards(vma, address - PAGE_SIZE);
}
if ((vma->vm_flags & VM_GROWSUP) && address + PAGE_SIZE == vma->vm_end) {
struct vm_area_struct *next = vma->vm_next;
if (next && next->vm_start == address + PAGE_SIZE)
return next->vm_flags & VM_GROWSUP ? 0 : -ENOMEM;
- expand_upwards(vma, address + PAGE_SIZE);
+ return expand_upwards(vma, address + PAGE_SIZE);
}
return 0;
}
/* Check if we need to add a guard page to the stack */
if (check_stack_guard_page(vma, address) < 0)
- return VM_FAULT_SIGBUS;
+ return VM_FAULT_SIGSEGV;
/* Use the zero-page for reads */
if (!(flags & FAULT_FLAG_WRITE)) {
return VM_FAULT_SIGBUS;
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;
return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
}
entry = *pte;
if (!pte_present(entry)) {
if (pte_none(entry)) {
- if (vma->vm_ops) {
+ if (vma->vm_ops)
return do_linear_fault(mm, vma, address,
- pte, pmd, flags, entry);
- }
+ pte, pmd, flags, entry);
return do_anonymous_page(mm, vma, address,
pte, pmd, flags);
}
/*
* By the time we get here, we already hold the mm semaphore
*/
-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 mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, unsigned int flags)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
- __set_current_state(TASK_RUNNING);
-
- count_vm_event(PGFAULT);
- mem_cgroup_count_vm_event(mm, PGFAULT);
-
- /* do counter updates before entering really critical section. */
- check_sync_rss_stat(current);
-
if (unlikely(is_vm_hugetlb_page(vma)))
return hugetlb_fault(mm, vma, address, flags);
return handle_pte_fault(mm, vma, address, pte, pmd, flags);
}
+int handle_mm_fault(struct mm_struct *mm, 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);
+
+ /* do counter updates before entering really critical section. */
+ check_sync_rss_stat(current);
+
+ /*
+ * Enable the memcg OOM handling for faults triggered in user
+ * space. Kernel faults are handled more gracefully.
+ */
+ if (flags & FAULT_FLAG_USER)
+ mem_cgroup_oom_enable();
+
+ ret = __handle_mm_fault(mm, vma, address, flags);
+
+ if (flags & FAULT_FLAG_USER) {
+ mem_cgroup_oom_disable();
+ /*
+ * The task may have entered a memcg OOM situation but
+ * if the allocation error was handled gracefully (no
+ * VM_FAULT_OOM), there is no need to kill anything.
+ * Just clean up the OOM state peacefully.
+ */
+ if (task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM))
+ mem_cgroup_oom_synchronize(false);
+ }
+
+ return ret;
+}
+
#ifndef __PAGETABLE_PUD_FOLDED
/*
* Allocate page upper directory.
if (follow_phys(vma, addr, write, &prot, &phys_addr))
return -EINVAL;
- maddr = ioremap_prot(phys_addr, PAGE_SIZE, prot);
+ maddr = ioremap_prot(phys_addr, PAGE_ALIGN(len + offset), prot);
if (write)
memcpy_toio(maddr + offset, buf, len);
else