int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
pfn_t pfn)
{
+ pgprot_t pgprot = vma->vm_page_prot;
+
BUG_ON(!(vma->vm_flags & VM_MIXEDMAP));
if (addr < vma->vm_start || addr >= vma->vm_end)
return -EFAULT;
+ if (track_pfn_insert(vma, &pgprot, pfn))
+ return -EINVAL;
/*
* If we don't have pte special, then we have to use the pfn_valid()
* result in pfn_t_has_page() == false.
*/
page = pfn_to_page(pfn_t_to_pfn(pfn));
- return insert_page(vma, addr, page, vma->vm_page_prot);
+ return insert_page(vma, addr, page, pgprot);
}
- return insert_pfn(vma, addr, pfn, vma->vm_page_prot);
+ return insert_pfn(vma, addr, pfn, pgprot);
}
EXPORT_SYMBOL(vm_insert_mixed);
mem_cgroup_oom_synchronize(false);
}
+ /*
+ * This mm has been already reaped by the oom reaper and so the
+ * refault cannot be trusted in general. Anonymous refaults would
+ * lose data and give a zero page instead e.g. This is especially
+ * problem for use_mm() because regular tasks will just die and
+ * the corrupted data will not be visible anywhere while kthread
+ * will outlive the oom victim and potentially propagate the date
+ * further.
+ */
+ if (unlikely((current->flags & PF_KTHREAD) && !(ret & VM_FAULT_ERROR)
+ && test_bit(MMF_UNSTABLE, &vma->vm_mm->flags)))
+ ret = VM_FAULT_SIGBUS;
+
return ret;
}
EXPORT_SYMBOL_GPL(handle_mm_fault);
* given task for page fault accounting.
*/
static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
- unsigned long addr, void *buf, int len, int write)
+ unsigned long addr, void *buf, int len, unsigned int gup_flags)
{
struct vm_area_struct *vma;
void *old_buf = buf;
+ int write = gup_flags & FOLL_WRITE;
down_read(&mm->mmap_sem);
/* ignore errors, just check how much was successfully transferred */
struct page *page = NULL;
ret = get_user_pages_remote(tsk, mm, addr, 1,
- write, 1, &page, &vma);
+ gup_flags, &page, &vma);
if (ret <= 0) {
#ifndef CONFIG_HAVE_IOREMAP_PROT
break;
int access_remote_vm(struct mm_struct *mm, unsigned long addr,
void *buf, int len, int write)
{
- return __access_remote_vm(NULL, mm, addr, buf, len, write);
+ unsigned int flags = FOLL_FORCE;
+
+ if (write)
+ flags |= FOLL_WRITE;
+
+ return __access_remote_vm(NULL, mm, addr, buf, len, flags);
}
/*
{
struct mm_struct *mm;
int ret;
+ unsigned int flags = FOLL_FORCE;
mm = get_task_mm(tsk);
if (!mm)
return 0;
- ret = __access_remote_vm(tsk, mm, addr, buf, len, write);
+ if (write)
+ flags |= FOLL_WRITE;
+
+ ret = __access_remote_vm(tsk, mm, addr, buf, len, flags);
+
mmput(mm);
return ret;