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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
commit03dd4cb26d967f9588437b0fc9cc0e8353322bb7 (patch)
treefa581f6dc1c0596391690d1f67eceef3af8246dc /arch/s390/mm/pgtable.c
parentd4e493caf788ef44982e131ff9c786546904d934 (diff)
Linux-libre 4.5-gnu
Diffstat (limited to 'arch/s390/mm/pgtable.c')
-rw-r--r--arch/s390/mm/pgtable.c58
1 files changed, 32 insertions, 26 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 54ef3bc01..510982788 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -55,7 +55,7 @@ int crst_table_upgrade(struct mm_struct *mm, unsigned long limit)
unsigned long entry;
int flush;
- BUG_ON(limit > (1UL << 53));
+ BUG_ON(limit > TASK_MAX_SIZE);
flush = 0;
repeat:
table = crst_table_alloc(mm);
@@ -133,7 +133,7 @@ void crst_table_downgrade(struct mm_struct *mm, unsigned long limit)
/**
* gmap_alloc - allocate a guest address space
* @mm: pointer to the parent mm_struct
- * @limit: maximum size of the gmap address space
+ * @limit: maximum address of the gmap address space
*
* Returns a guest address space structure.
*/
@@ -402,7 +402,7 @@ int gmap_map_segment(struct gmap *gmap, unsigned long from,
if ((from | to | len) & (PMD_SIZE - 1))
return -EINVAL;
if (len == 0 || from + len < from || to + len < to ||
- from + len > TASK_MAX_SIZE || to + len > gmap->asce_end)
+ from + len - 1 > TASK_MAX_SIZE || to + len - 1 > gmap->asce_end)
return -EINVAL;
flush = 0;
@@ -578,17 +578,29 @@ int gmap_fault(struct gmap *gmap, unsigned long gaddr,
{
unsigned long vmaddr;
int rc;
+ bool unlocked;
down_read(&gmap->mm->mmap_sem);
+
+retry:
+ unlocked = false;
vmaddr = __gmap_translate(gmap, gaddr);
if (IS_ERR_VALUE(vmaddr)) {
rc = vmaddr;
goto out_up;
}
- if (fixup_user_fault(current, gmap->mm, vmaddr, fault_flags)) {
+ if (fixup_user_fault(current, gmap->mm, vmaddr, fault_flags,
+ &unlocked)) {
rc = -EFAULT;
goto out_up;
}
+ /*
+ * In the case that fixup_user_fault unlocked the mmap_sem during
+ * faultin redo __gmap_translate to not race with a map/unmap_segment.
+ */
+ if (unlocked)
+ goto retry;
+
rc = __gmap_link(gmap, gaddr, vmaddr);
out_up:
up_read(&gmap->mm->mmap_sem);
@@ -603,10 +615,7 @@ static void gmap_zap_swap_entry(swp_entry_t entry, struct mm_struct *mm)
else if (is_migration_entry(entry)) {
struct page *page = migration_entry_to_page(entry);
- if (PageAnon(page))
- dec_mm_counter(mm, MM_ANONPAGES);
- else
- dec_mm_counter(mm, MM_FILEPAGES);
+ dec_mm_counter(mm, mm_counter(page));
}
free_swap_and_cache(entry);
}
@@ -717,12 +726,14 @@ int gmap_ipte_notify(struct gmap *gmap, unsigned long gaddr, unsigned long len)
spinlock_t *ptl;
pte_t *ptep, entry;
pgste_t pgste;
+ bool unlocked;
int rc = 0;
if ((gaddr & ~PAGE_MASK) || (len & ~PAGE_MASK))
return -EINVAL;
down_read(&gmap->mm->mmap_sem);
while (len) {
+ unlocked = false;
/* Convert gmap address and connect the page tables */
addr = __gmap_translate(gmap, gaddr);
if (IS_ERR_VALUE(addr)) {
@@ -730,10 +741,14 @@ int gmap_ipte_notify(struct gmap *gmap, unsigned long gaddr, unsigned long len)
break;
}
/* Get the page mapped */
- if (fixup_user_fault(current, gmap->mm, addr, FAULT_FLAG_WRITE)) {
+ if (fixup_user_fault(current, gmap->mm, addr, FAULT_FLAG_WRITE,
+ &unlocked)) {
rc = -EFAULT;
break;
}
+ /* While trying to map mmap_sem got unlocked. Let us retry */
+ if (unlocked)
+ continue;
rc = __gmap_link(gmap, gaddr, addr);
if (rc)
break;
@@ -794,9 +809,11 @@ int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
spinlock_t *ptl;
pgste_t old, new;
pte_t *ptep;
+ bool unlocked;
down_read(&mm->mmap_sem);
retry:
+ unlocked = false;
ptep = get_locked_pte(mm, addr, &ptl);
if (unlikely(!ptep)) {
up_read(&mm->mmap_sem);
@@ -805,7 +822,12 @@ retry:
if (!(pte_val(*ptep) & _PAGE_INVALID) &&
(pte_val(*ptep) & _PAGE_PROTECT)) {
pte_unmap_unlock(ptep, ptl);
- if (fixup_user_fault(current, mm, addr, FAULT_FLAG_WRITE)) {
+ /*
+ * We do not really care about unlocked. We will retry either
+ * way. But this allows fixup_user_fault to enable userfaultfd.
+ */
+ if (fixup_user_fault(current, mm, addr, FAULT_FLAG_WRITE,
+ &unlocked)) {
up_read(&mm->mmap_sem);
return -EFAULT;
}
@@ -1308,22 +1330,6 @@ int pmdp_set_access_flags(struct vm_area_struct *vma,
return 1;
}
-static void pmdp_splitting_flush_sync(void *arg)
-{
- /* Simply deliver the interrupt */
-}
-
-void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
- pmd_t *pmdp)
-{
- VM_BUG_ON(address & ~HPAGE_PMD_MASK);
- if (!test_and_set_bit(_SEGMENT_ENTRY_SPLIT_BIT,
- (unsigned long *) pmdp)) {
- /* need to serialize against gup-fast (IRQ disabled) */
- smp_call_function(pmdp_splitting_flush_sync, NULL, 1);
- }
-}
-
void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
pgtable_t pgtable)
{