Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 fixes from Martin Schwidefsky:
 - A proper fix for the locking issue in the dasd driver
 - Wire up the new preadv2 nad pwritev2 system calls
 - Add the mark_rodata_ro function and set DEBUG_RODATA=y
 - A few more bug fixes.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390: wire up preadv2/pwritev2 syscalls
  s390/pci: PCI function group 0 is valid for clp_query_pci_fn
  s390/crypto: provide correct file mode at device register.
  s390/mm: handle PTE-mapped tail pages in fast gup
  s390: add DEBUG_RODATA support
  s390: disable postinit-readonly for now
  s390/dasd: reorder lcu and device lock
  s390/cpum_sf: Fix cpu hotplug notifier transitions
  s390/cpum_cf: Fix missing cpu hotplug notifier transition

2 files changed, 12 insertions, 6 deletions

diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c
index 49a1c84ed266..a8a6765f1a51 100644
--- a/arch/s390/mm/gup.c
+++ b/arch/s390/mm/gup.c
@@ -20,9 +20,9 @@
 static inline int gup_pte_range(pmd_t *pmdp, pmd_t pmd, unsigned long addr,
                 unsigned long end, int write, struct page **pages, int *nr)
 {
+        struct page *head, *page;
         unsigned long mask;
         pte_t *ptep, pte;
-        struct page *page;
 
         mask = (write ? _PAGE_PROTECT : 0) | _PAGE_INVALID | _PAGE_SPECIAL;
 
@@ -37,12 +37,14 @@ static inline int gup_pte_range(pmd_t *pmdp, pmd_t pmd, unsigned long addr,
                         return 0;
                 VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
                 page = pte_page(pte);
-                if (!page_cache_get_speculative(page))
+                head = compound_head(page);
+                if (!page_cache_get_speculative(head))
                         return 0;
                 if (unlikely(pte_val(pte) != pte_val(*ptep))) {
-                        put_page(page);
+                        put_page(head);
                         return 0;
                 }
+                VM_BUG_ON_PAGE(compound_head(page) != head, page);
                 pages[*nr] = page;
                 (*nr)++;
 
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 73e290337092..c7b0451397d6 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -108,6 +108,13 @@ void __init paging_init(void)
         free_area_init_nodes(max_zone_pfns);
 }
 
+void mark_rodata_ro(void)
+{
+        /* Text and rodata are already protected. Nothing to do here. */
+        pr_info("Write protecting the kernel read-only data: %luk\n",
+                ((unsigned long)&_eshared - (unsigned long)&_stext) >> 10);
+}
+
 void __init mem_init(void)
 {
         if (MACHINE_HAS_TLB_LC)
@@ -126,9 +133,6 @@ void __init mem_init(void)
         setup_zero_pages();     /* Setup zeroed pages. */
 
         mem_init_print_info(NULL);
-        printk("Write protected kernel read-only data: %#lx - %#lx\n",
-               (unsigned long)&_stext,
-               PFN_ALIGN((unsigned long)&_eshared) - 1);
 }
 
 void free_initmem(void)