}
EXPORT_SYMBOL(vm_insert_page);
-static int insert_pfn(struct vm_area_struct *vma, unsigned long addr,
+static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr,
pfn_t pfn, pgprot_t prot, bool mkwrite)
{
struct mm_struct *mm = vma->vm_mm;
- int retval;
pte_t *pte, entry;
spinlock_t *ptl;
- retval = -ENOMEM;
pte = get_locked_pte(mm, addr, &ptl);
if (!pte)
- goto out;
- retval = -EBUSY;
+ return VM_FAULT_OOM;
if (!pte_none(*pte)) {
if (mkwrite) {
/*
* in may not match the PFN we have mapped if the
* mapped PFN is a writeable COW page. In the mkwrite
* case we are creating a writable PTE for a shared
- * mapping and we expect the PFNs to match.
+ * mapping and we expect the PFNs to match. If they
+ * don't match, we are likely racing with block
+ * allocation and mapping invalidation so just skip the
+ * update.
*/
- if (WARN_ON_ONCE(pte_pfn(*pte) != pfn_t_to_pfn(pfn)))
+ if (pte_pfn(*pte) != pfn_t_to_pfn(pfn)) {
+ WARN_ON_ONCE(!is_zero_pfn(pte_pfn(*pte)));
goto out_unlock;
+ }
entry = *pte;
goto out_mkwrite;
} else
set_pte_at(mm, addr, pte, entry);
update_mmu_cache(vma, addr, pte); /* XXX: why not for insert_page? */
- retval = 0;
out_unlock:
pte_unmap_unlock(pte, ptl);
-out:
- return retval;
-}
-
-/**
- * vm_insert_pfn - insert single pfn into user vma
- * @vma: user vma to map to
- * @addr: target user address of this page
- * @pfn: source kernel pfn
- *
- * Similar to vm_insert_page, this allows drivers to insert individual pages
- * they've allocated into a user vma. Same comments apply.
- *
- * This function should only be called from a vm_ops->fault handler, and
- * in that case the handler should return NULL.
- *
- * vma cannot be a COW mapping.
- *
- * As this is called only for pages that do not currently exist, we
- * do not need to flush old virtual caches or the TLB.
- */
-int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
- unsigned long pfn)
-{
- return vm_insert_pfn_prot(vma, addr, pfn, vma->vm_page_prot);
+ return VM_FAULT_NOPAGE;
}
-EXPORT_SYMBOL(vm_insert_pfn);
/**
- * vm_insert_pfn_prot - insert single pfn into user vma with specified pgprot
+ * vmf_insert_pfn_prot - insert single pfn into user vma with specified pgprot
* @vma: user vma to map to
* @addr: target user address of this page
* @pfn: source kernel pfn
* @pgprot: pgprot flags for the inserted page
*
- * This is exactly like vm_insert_pfn, except that it allows drivers to
+ * This is exactly like vmf_insert_pfn(), except that it allows drivers to
* to override pgprot on a per-page basis.
*
* This only makes sense for IO mappings, and it makes no sense for
- * cow mappings. In general, using multiple vmas is preferable;
- * vm_insert_pfn_prot should only be used if using multiple VMAs is
+ * COW mappings. In general, using multiple vmas is preferable;
+ * vmf_insert_pfn_prot should only be used if using multiple VMAs is
* impractical.
+ *
+ * Context: Process context. May allocate using %GFP_KERNEL.
+ * Return: vm_fault_t value.
*/
-int vm_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
+vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn, pgprot_t pgprot)
{
- int ret;
/*
* Technically, architectures with pte_special can avoid all these
* restrictions (same for remap_pfn_range). However we would like
BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn));
if (addr < vma->vm_start || addr >= vma->vm_end)
- return -EFAULT;
+ return VM_FAULT_SIGBUS;
if (!pfn_modify_allowed(pfn, pgprot))
- return -EACCES;
+ return VM_FAULT_SIGBUS;
track_pfn_insert(vma, &pgprot, __pfn_to_pfn_t(pfn, PFN_DEV));
- ret = insert_pfn(vma, addr, __pfn_to_pfn_t(pfn, PFN_DEV), pgprot,
+ return insert_pfn(vma, addr, __pfn_to_pfn_t(pfn, PFN_DEV), pgprot,
false);
+}
+EXPORT_SYMBOL(vmf_insert_pfn_prot);
- return ret;
+/**
+ * vmf_insert_pfn - insert single pfn into user vma
+ * @vma: user vma to map to
+ * @addr: target user address of this page
+ * @pfn: source kernel pfn
+ *
+ * Similar to vm_insert_page, this allows drivers to insert individual pages
+ * they've allocated into a user vma. Same comments apply.
+ *
+ * This function should only be called from a vm_ops->fault handler, and
+ * in that case the handler should return the result of this function.
+ *
+ * vma cannot be a COW mapping.
+ *
+ * As this is called only for pages that do not currently exist, we
+ * do not need to flush old virtual caches or the TLB.
+ *
+ * Context: Process context. May allocate using %GFP_KERNEL.
+ * Return: vm_fault_t value.
+ */
+vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
+ unsigned long pfn)
+{
+ return vmf_insert_pfn_prot(vma, addr, pfn, vma->vm_page_prot);
}
-EXPORT_SYMBOL(vm_insert_pfn_prot);
+EXPORT_SYMBOL(vmf_insert_pfn);
static bool vm_mixed_ok(struct vm_area_struct *vma, pfn_t pfn)
{
return false;
}
-static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
- pfn_t pfn, bool mkwrite)
+static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
+ unsigned long addr, pfn_t pfn, bool mkwrite)
{
pgprot_t pgprot = vma->vm_page_prot;
+ int err;
BUG_ON(!vm_mixed_ok(vma, pfn));
if (addr < vma->vm_start || addr >= vma->vm_end)
- return -EFAULT;
+ return VM_FAULT_SIGBUS;
track_pfn_insert(vma, &pgprot, pfn);
if (!pfn_modify_allowed(pfn_t_to_pfn(pfn), pgprot))
- return -EACCES;
+ return VM_FAULT_SIGBUS;
/*
* 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, pgprot);
+ err = insert_page(vma, addr, page, pgprot);
+ } else {
+ return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
}
- return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
+
+ if (err == -ENOMEM)
+ return VM_FAULT_OOM;
+ if (err < 0 && err != -EBUSY)
+ return VM_FAULT_SIGBUS;
+
+ return VM_FAULT_NOPAGE;
}
-int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
- pfn_t pfn)
+vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
+ pfn_t pfn)
{
return __vm_insert_mixed(vma, addr, pfn, false);
-
}
-EXPORT_SYMBOL(vm_insert_mixed);
+EXPORT_SYMBOL(vmf_insert_mixed);
/*
* If the insertion of PTE failed because someone else already added a
* different entry in the mean time, we treat that as success as we assume
* the same entry was actually inserted.
*/
-
vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
unsigned long addr, pfn_t pfn)
{
- int err;
-
- err = __vm_insert_mixed(vma, addr, pfn, true);
- if (err == -ENOMEM)
- return VM_FAULT_OOM;
- if (err < 0 && err != -EBUSY)
- return VM_FAULT_SIGBUS;
- return VM_FAULT_NOPAGE;
+ return __vm_insert_mixed(vma, addr, pfn, true);
}
EXPORT_SYMBOL(vmf_insert_mixed_mkwrite);
struct vm_area_struct *vma = vmf->vma;
vm_fault_t ret;
- /* The VMA was not fully populated on mmap() or missing VM_DONTEXPAND */
- if (!vma->vm_ops->fault)
- ret = VM_FAULT_SIGBUS;
- else if (!(vmf->flags & FAULT_FLAG_WRITE))
+ /*
+ * The VMA was not fully populated on mmap() or missing VM_DONTEXPAND
+ */
+ if (!vma->vm_ops->fault) {
+ /*
+ * If we find a migration pmd entry or a none pmd entry, which
+ * should never happen, return SIGBUS
+ */
+ if (unlikely(!pmd_present(*vmf->pmd)))
+ ret = VM_FAULT_SIGBUS;
+ else {
+ vmf->pte = pte_offset_map_lock(vmf->vma->vm_mm,
+ vmf->pmd,
+ vmf->address,
+ &vmf->ptl);
+ /*
+ * Make sure this is not a temporary clearing of pte
+ * by holding ptl and checking again. A R/M/W update
+ * of pte involves: take ptl, clearing the pte so that
+ * we don't have concurrent modification by hardware
+ * followed by an update.
+ */
+ if (unlikely(pte_none(*vmf->pte)))
+ ret = VM_FAULT_SIGBUS;
+ else
+ ret = VM_FAULT_NOPAGE;
+
+ pte_unmap_unlock(vmf->pte, vmf->ptl);
+ }
+ } else if (!(vmf->flags & FAULT_FLAG_WRITE))
ret = do_read_fault(vmf);
else if (!(vma->vm_flags & VM_SHARED))
ret = do_cow_fault(vmf);
git.samba.org / sfrench / cifs-2.6.git / blobdiff