Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "8 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  lib/test_kmod.c: fix limit check on number of test devices created
  selftests/vm/run_vmtests: adjust hugetlb size according to nr_cpus
  mm/page_alloc: fix memmap_init_zone pageblock alignment
  mm/memblock.c: hardcode the end_pfn being -1
  mm/gup.c: teach get_user_pages_unlocked to handle FOLL_NOWAIT
  lib/bug.c: exclude non-BUG/WARN exceptions from report_bug()
  bug: use %pB in BUG and stack protector failure
  hugetlb: fix surplus pages accounting

kernel/panic.c

@@ -640,7 +640,7 @@ device_initcall(register_warn_debugfs);
  */
 __visible void __stack_chk_fail(void)
 {
-	panic("stack-protector: Kernel stack is corrupted in: %p\n",
+	panic("stack-protector: Kernel stack is corrupted in: %pB\n",
 		__builtin_return_address(0));
 }
 EXPORT_SYMBOL(__stack_chk_fail);

lib/bug.c

@@ -150,6 +150,8 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
 		return BUG_TRAP_TYPE_NONE;
 
 	bug = find_bug(bugaddr);
+	if (!bug)
+		return BUG_TRAP_TYPE_NONE;
 
 	file = NULL;
 	line = 0;
@@ -191,7 +193,7 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
 	if (file)
 		pr_crit("kernel BUG at %s:%u!\n", file, line);
 	else
-		pr_crit("Kernel BUG at %p [verbose debug info unavailable]\n",
+		pr_crit("Kernel BUG at %pB [verbose debug info unavailable]\n",
 			(void *)bugaddr);
 
 	return BUG_TRAP_TYPE_BUG;

lib/test_kmod.c

@@ -1141,7 +1141,7 @@ static struct kmod_test_device *register_test_dev_kmod(void)
 	mutex_lock(&reg_dev_mutex);
 
 	/* int should suffice for number of devices, test for wrap */
-	if (unlikely(num_test_devs + 1) < 0) {
+	if (num_test_devs + 1 == INT_MAX) {
 		pr_err("reached limit of number of test devices\n");
 		goto out;
 	}

mm/gup.c

@@ -516,7 +516,7 @@ static int faultin_page(struct task_struct *tsk, struct vm_area_struct *vma,
 	}
 
 	if (ret & VM_FAULT_RETRY) {
-		if (nonblocking)
+		if (nonblocking && !(fault_flags & FAULT_FLAG_RETRY_NOWAIT))
 			*nonblocking = 0;
 		return -EBUSY;
 	}
@@ -890,7 +890,10 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk,
 				break;
 		}
 		if (*locked) {
-			/* VM_FAULT_RETRY didn't trigger */
+			/*
+			 * VM_FAULT_RETRY didn't trigger or it was a
+			 * FOLL_NOWAIT.
+			 */
 			if (!pages_done)
 				pages_done = ret;
 			break;

mm/hugetlb.c

@@ -1583,7 +1583,7 @@ static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask,
 		page = NULL;
 	} else {
 		h->surplus_huge_pages++;
-		h->nr_huge_pages_node[page_to_nid(page)]++;
+		h->surplus_huge_pages_node[page_to_nid(page)]++;
 	}
 
 out_unlock:

mm/memblock.c

@@ -1107,7 +1107,7 @@ unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn,
 	struct memblock_type *type = &memblock.memory;
 	unsigned int right = type->cnt;
 	unsigned int mid, left = 0;
-	phys_addr_t addr = PFN_PHYS(pfn + 1);
+	phys_addr_t addr = PFN_PHYS(++pfn);
 
 	do {
 		mid = (right + left) / 2;
@@ -1118,15 +1118,15 @@ unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn,
 				  type->regions[mid].size))
 			left = mid + 1;
 		else {
-			/* addr is within the region, so pfn + 1 is valid */
-			return min(pfn + 1, max_pfn);
+			/* addr is within the region, so pfn is valid */
+			return pfn;
 		}
 	} while (left < right);
 
 	if (right == type->cnt)
-		return max_pfn;
+		return -1UL;
 	else
-		return min(PHYS_PFN(type->regions[right].base), max_pfn);
+		return PHYS_PFN(type->regions[right].base);
 }
 
 /**

mm/page_alloc.c

@@ -5359,9 +5359,14 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
 			/*
 			 * Skip to the pfn preceding the next valid one (or
 			 * end_pfn), such that we hit a valid pfn (or end_pfn)
-			 * on our next iteration of the loop.
-			 */
-			pfn = memblock_next_valid_pfn(pfn, end_pfn) - 1;
+			 * on our next iteration of the loop. Note that it needs
+			 * to be pageblock aligned even when the region itself
+			 * is not. move_freepages_block() can shift ahead of
+			 * the valid region but still depends on correct page
+			 * metadata.
+			 */
+			pfn = (memblock_next_valid_pfn(pfn, end_pfn) &
+					~(pageblock_nr_pages-1)) - 1;
 #endif
 			continue;
 		}

tools/testing/selftests/vm/run_vmtests

@@ -2,25 +2,33 @@
 # SPDX-License-Identifier: GPL-2.0
 #please run as root
 
-#we need 256M, below is the size in kB
-needmem=262144
 mnt=./huge
 exitcode=0
 
-#get pagesize and freepages from /proc/meminfo
+#get huge pagesize and freepages from /proc/meminfo
 while read name size unit; do
 	if [ "$name" = "HugePages_Free:" ]; then
 		freepgs=$size
 	fi
 	if [ "$name" = "Hugepagesize:" ]; then
-		pgsize=$size
+		hpgsize_KB=$size
 	fi
 done < /proc/meminfo
 
+# Simple hugetlbfs tests have a hardcoded minimum requirement of
+# huge pages totaling 256MB (262144KB) in size.  The userfaultfd
+# hugetlb test requires a minimum of 2 * nr_cpus huge pages.  Take
+# both of these requirements into account and attempt to increase
+# number of huge pages available.
+nr_cpus=$(nproc)
+hpgsize_MB=$((hpgsize_KB / 1024))
+half_ufd_size_MB=$((((nr_cpus * hpgsize_MB + 127) / 128) * 128))
+needmem_KB=$((half_ufd_size_MB * 2 * 1024))
+
 #set proper nr_hugepages
-if [ -n "$freepgs" ] && [ -n "$pgsize" ]; then
+if [ -n "$freepgs" ] && [ -n "$hpgsize_KB" ]; then
 	nr_hugepgs=`cat /proc/sys/vm/nr_hugepages`
-	needpgs=`expr $needmem / $pgsize`
+	needpgs=$((needmem_KB / hpgsize_KB))
 	tries=2
 	while [ $tries -gt 0 ] && [ $freepgs -lt $needpgs ]; do
 		lackpgs=$(( $needpgs - $freepgs ))
@@ -107,8 +115,9 @@ fi
 echo "---------------------------"
 echo "running userfaultfd_hugetlb"
 echo "---------------------------"
-# 256MB total huge pages == 128MB src and 128MB dst
-./userfaultfd hugetlb 128 32 $mnt/ufd_test_file
+# Test requires source and destination huge pages.  Size of source
+# (half_ufd_size_MB) is passed as argument to test.
+./userfaultfd hugetlb $half_ufd_size_MB 32 $mnt/ufd_test_file
 if [ $? -ne 0 ]; then
 	echo "[FAIL]"
 	exitcode=1