diff options
Diffstat (limited to 'arch/s390/mm/gmap.c')
| -rw-r--r-- | arch/s390/mm/gmap.c | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index dc90d1eb0d55..f4b6fc746fce 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -895,12 +895,12 @@ static int gmap_pte_op_fixup(struct gmap *gmap, unsigned long gaddr, /** * gmap_pte_op_end - release the page table lock - * @ptl: pointer to the spinlock pointer + * @ptep: pointer to the locked pte + * @ptl: pointer to the page table spinlock */ -static void gmap_pte_op_end(spinlock_t *ptl) +static void gmap_pte_op_end(pte_t *ptep, spinlock_t *ptl) { - if (ptl) - spin_unlock(ptl); + pte_unmap_unlock(ptep, ptl); } /** @@ -1011,7 +1011,7 @@ static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr, { int rc; pte_t *ptep; - spinlock_t *ptl = NULL; + spinlock_t *ptl; unsigned long pbits = 0; if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID) @@ -1025,7 +1025,7 @@ static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr, pbits |= (bits & GMAP_NOTIFY_SHADOW) ? PGSTE_VSIE_BIT : 0; /* Protect and unlock. */ rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, pbits); - gmap_pte_op_end(ptl); + gmap_pte_op_end(ptep, ptl); return rc; } @@ -1154,7 +1154,7 @@ int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val) /* Do *NOT* clear the _PAGE_INVALID bit! */ rc = 0; } - gmap_pte_op_end(ptl); + gmap_pte_op_end(ptep, ptl); } if (!rc) break; @@ -1248,7 +1248,7 @@ static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr, if (!rc) gmap_insert_rmap(sg, vmaddr, rmap); spin_unlock(&sg->guest_table_lock); - gmap_pte_op_end(ptl); + gmap_pte_op_end(ptep, ptl); } radix_tree_preload_end(); if (rc) { @@ -2156,7 +2156,7 @@ int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte) tptep = (pte_t *) gmap_table_walk(sg, saddr, 0); if (!tptep) { spin_unlock(&sg->guest_table_lock); - gmap_pte_op_end(ptl); + gmap_pte_op_end(sptep, ptl); radix_tree_preload_end(); break; } @@ -2167,7 +2167,7 @@ int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte) rmap = NULL; rc = 0; } - gmap_pte_op_end(ptl); + gmap_pte_op_end(sptep, ptl); spin_unlock(&sg->guest_table_lock); } radix_tree_preload_end(); @@ -2495,7 +2495,7 @@ void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long bitmap[4], continue; if (ptep_test_and_clear_uc(gmap->mm, vmaddr, ptep)) set_bit(i, bitmap); - spin_unlock(ptl); + pte_unmap_unlock(ptep, ptl); } } gmap_pmd_op_end(gmap, pmdp); @@ -2537,7 +2537,12 @@ static inline void thp_split_mm(struct mm_struct *mm) * Remove all empty zero pages from the mapping for lazy refaulting * - This must be called after mm->context.has_pgste is set, to avoid * future creation of zero pages - * - This must be called after THP was enabled + * - This must be called after THP was disabled. + * + * mm contracts with s390, that even if mm were to remove a page table, + * racing with the loop below and so causing pte_offset_map_lock() to fail, + * it will never insert a page table containing empty zero pages once + * mm_forbids_zeropage(mm) i.e. mm->context.has_pgste is set. */ static int __zap_zero_pages(pmd_t *pmd, unsigned long start, unsigned long end, struct mm_walk *walk) @@ -2549,6 +2554,8 @@ static int __zap_zero_pages(pmd_t *pmd, unsigned long start, spinlock_t *ptl; ptep = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); + if (!ptep) + break; if (is_zero_pfn(pte_pfn(*ptep))) ptep_xchg_direct(walk->mm, addr, ptep, __pte(_PAGE_INVALID)); pte_unmap_unlock(ptep, ptl); |