Merge tag 'v5.4.24' into imx_5.4.y

Merge Linux stable release v5.4.24 into imx_5.4.y

* tag 'v5.4.24': (3306 commits)
  Linux 5.4.24
  blktrace: Protect q->blk_trace with RCU
  kvm: nVMX: VMWRITE checks unsupported field before read-only field
  ...

Signed-off-by: Jason Liu <jason.hui.liu@nxp.com>

 Conflicts:
	arch/arm/boot/dts/imx6sll-evk.dts
	arch/arm/boot/dts/imx7ulp.dtsi
	arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi
	drivers/clk/imx/clk-composite-8m.c
	drivers/gpio/gpio-mxc.c
	drivers/irqchip/Kconfig
	drivers/mmc/host/sdhci-of-esdhc.c
	drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
	drivers/net/can/flexcan.c
	drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
	drivers/net/ethernet/mscc/ocelot.c
	drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
	drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
	drivers/net/phy/realtek.c
	drivers/pci/controller/mobiveil/pcie-mobiveil-host.c
	drivers/perf/fsl_imx8_ddr_perf.c
	drivers/tee/optee/shm_pool.c
	drivers/usb/cdns3/gadget.c
	kernel/sched/cpufreq.c
	net/core/xdp.c
	sound/soc/fsl/fsl_esai.c
	sound/soc/fsl/fsl_sai.c
	sound/soc/sof/core.c
	sound/soc/sof/imx/Kconfig
	sound/soc/sof/loader.c

13 files changed, 170 insertions, 120 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 93d97f9b0157..f61d834e02fe 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -299,17 +299,6 @@ config HEADERS_INSTALL
 	  user-space program samples. It is also needed by some features such
 	  as uapi header sanity checks.
 
-config HEADERS_CHECK
-	bool "Run sanity checks on uapi headers when building 'all'"
-	depends on HEADERS_INSTALL
-	help
-	  This option will run basic sanity checks on uapi headers when
-	  building the 'all' target, for example, ensure that they do not
-	  attempt to include files which were not exported, etc.
-
-	  If you're making modifications to header files which are
-	  relevant for userspace, say 'Y'.
-
 config OPTIMIZE_INLINING
 	def_bool y
 	help
diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index 61261195f5b6..48054dbf1b51 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -132,14 +132,18 @@ static void fill_pool(void)
 	struct debug_obj *obj;
 	unsigned long flags;
 
-	if (likely(obj_pool_free >= debug_objects_pool_min_level))
+	if (likely(READ_ONCE(obj_pool_free) >= debug_objects_pool_min_level))
 		return;
 
 	/*
 	 * Reuse objs from the global free list; they will be reinitialized
 	 * when allocating.
+	 *
+	 * Both obj_nr_tofree and obj_pool_free are checked locklessly; the
+	 * READ_ONCE()s pair with the WRITE_ONCE()s in pool_lock critical
+	 * sections.
 	 */
-	while (obj_nr_tofree && (obj_pool_free < obj_pool_min_free)) {
+	while (READ_ONCE(obj_nr_tofree) && (READ_ONCE(obj_pool_free) < obj_pool_min_free)) {
 		raw_spin_lock_irqsave(&pool_lock, flags);
 		/*
 		 * Recheck with the lock held as the worker thread might have
@@ -148,9 +152,9 @@ static void fill_pool(void)
 		while (obj_nr_tofree && (obj_pool_free < obj_pool_min_free)) {
 			obj = hlist_entry(obj_to_free.first, typeof(*obj), node);
 			hlist_del(&obj->node);
-			obj_nr_tofree--;
+			WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1);
 			hlist_add_head(&obj->node, &obj_pool);
-			obj_pool_free++;
+			WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
 		}
 		raw_spin_unlock_irqrestore(&pool_lock, flags);
 	}
@@ -158,7 +162,7 @@ static void fill_pool(void)
 	if (unlikely(!obj_cache))
 		return;
 
-	while (obj_pool_free < debug_objects_pool_min_level) {
+	while (READ_ONCE(obj_pool_free) < debug_objects_pool_min_level) {
 		struct debug_obj *new[ODEBUG_BATCH_SIZE];
 		int cnt;
 
@@ -174,7 +178,7 @@ static void fill_pool(void)
 		while (cnt) {
 			hlist_add_head(&new[--cnt]->node, &obj_pool);
 			debug_objects_allocated++;
-			obj_pool_free++;
+			WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
 		}
 		raw_spin_unlock_irqrestore(&pool_lock, flags);
 	}
@@ -236,7 +240,7 @@ alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
 	obj = __alloc_object(&obj_pool);
 	if (obj) {
 		obj_pool_used++;
-		obj_pool_free--;
+		WRITE_ONCE(obj_pool_free, obj_pool_free - 1);
 
 		/*
 		 * Looking ahead, allocate one batch of debug objects and
@@ -255,7 +259,7 @@ alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
 					       &percpu_pool->free_objs);
 				percpu_pool->obj_free++;
 				obj_pool_used++;
-				obj_pool_free--;
+				WRITE_ONCE(obj_pool_free, obj_pool_free - 1);
 			}
 		}
 
@@ -309,8 +313,8 @@ static void free_obj_work(struct work_struct *work)
 		obj = hlist_entry(obj_to_free.first, typeof(*obj), node);
 		hlist_del(&obj->node);
 		hlist_add_head(&obj->node, &obj_pool);
-		obj_pool_free++;
-		obj_nr_tofree--;
+		WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
+		WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1);
 	}
 	raw_spin_unlock_irqrestore(&pool_lock, flags);
 	return;
@@ -324,7 +328,7 @@ free_objs:
 	if (obj_nr_tofree) {
 		hlist_move_list(&obj_to_free, &tofree);
 		debug_objects_freed += obj_nr_tofree;
-		obj_nr_tofree = 0;
+		WRITE_ONCE(obj_nr_tofree, 0);
 	}
 	raw_spin_unlock_irqrestore(&pool_lock, flags);
 
@@ -375,10 +379,10 @@ free_to_obj_pool:
 	obj_pool_used--;
 
 	if (work) {
-		obj_nr_tofree++;
+		WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1);
 		hlist_add_head(&obj->node, &obj_to_free);
 		if (lookahead_count) {
-			obj_nr_tofree += lookahead_count;
+			WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + lookahead_count);
 			obj_pool_used -= lookahead_count;
 			while (lookahead_count) {
 				hlist_add_head(&objs[--lookahead_count]->node,
@@ -396,15 +400,15 @@ free_to_obj_pool:
 			for (i = 0; i < ODEBUG_BATCH_SIZE; i++) {
 				obj = __alloc_object(&obj_pool);
 				hlist_add_head(&obj->node, &obj_to_free);
-				obj_pool_free--;
-				obj_nr_tofree++;
+				WRITE_ONCE(obj_pool_free, obj_pool_free - 1);
+				WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1);
 			}
 		}
 	} else {
-		obj_pool_free++;
+		WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
 		hlist_add_head(&obj->node, &obj_pool);
 		if (lookahead_count) {
-			obj_pool_free += lookahead_count;
+			WRITE_ONCE(obj_pool_free, obj_pool_free + lookahead_count);
 			obj_pool_used -= lookahead_count;
 			while (lookahead_count) {
 				hlist_add_head(&objs[--lookahead_count]->node,
@@ -423,7 +427,7 @@ free_to_obj_pool:
 static void free_object(struct debug_obj *obj)
 {
 	__free_object(obj);
-	if (!obj_freeing && obj_nr_tofree) {
+	if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) {
 		WRITE_ONCE(obj_freeing, true);
 		schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY);
 	}
@@ -982,7 +986,7 @@ repeat:
 		debug_objects_maxchecked = objs_checked;
 
 	/* Schedule work to actually kmem_cache_free() objects */
-	if (!obj_freeing && obj_nr_tofree) {
+	if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) {
 		WRITE_ONCE(obj_freeing, true);
 		schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY);
 	}
@@ -1008,12 +1012,12 @@ static int debug_stats_show(struct seq_file *m, void *v)
 	seq_printf(m, "max_checked   :%d\n", debug_objects_maxchecked);
 	seq_printf(m, "warnings      :%d\n", debug_objects_warnings);
 	seq_printf(m, "fixups        :%d\n", debug_objects_fixups);
-	seq_printf(m, "pool_free     :%d\n", obj_pool_free + obj_percpu_free);
+	seq_printf(m, "pool_free     :%d\n", READ_ONCE(obj_pool_free) + obj_percpu_free);
 	seq_printf(m, "pool_pcp_free :%d\n", obj_percpu_free);
 	seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
 	seq_printf(m, "pool_used     :%d\n", obj_pool_used - obj_percpu_free);
 	seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
-	seq_printf(m, "on_free_list  :%d\n", obj_nr_tofree);
+	seq_printf(m, "on_free_list  :%d\n", READ_ONCE(obj_nr_tofree));
 	seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated);
 	seq_printf(m, "objs_freed    :%d\n", debug_objects_freed);
 	return 0;
diff --git a/lib/raid6/mktables.c b/lib/raid6/mktables.c
index 9c485df1308f..f02e10fa6238 100644
--- a/lib/raid6/mktables.c
+++ b/lib/raid6/mktables.c
@@ -56,8 +56,8 @@ int main(int argc, char *argv[])
 	uint8_t v;
 	uint8_t exptbl[256], invtbl[256];
 
-	printf("#include <linux/raid/pq.h>\n");
 	printf("#include <linux/export.h>\n");
+	printf("#include <linux/raid/pq.h>\n");
 
 	/* Compute multiplication table */
 	printf("\nconst u8  __attribute__((aligned(256)))\n"
diff --git a/lib/raid6/unroll.awk b/lib/raid6/unroll.awk
index c6aa03631df8..0809805a7e23 100644
--- a/lib/raid6/unroll.awk
+++ b/lib/raid6/unroll.awk
@@ -13,7 +13,7 @@ BEGIN {
 	for (i = 0; i < rep; ++i) {
 		tmp = $0
 		gsub(/\$\$/, i, tmp)
-		gsub(/\$\#/, n, tmp)
+		gsub(/\$#/, n, tmp)
 		gsub(/\$\*/, "$", tmp)
 		print tmp
 	}
diff --git a/lib/sbitmap.c b/lib/sbitmap.c
index 969e5400a615..ee3ce1494568 100644
--- a/lib/sbitmap.c
+++ b/lib/sbitmap.c
@@ -667,8 +667,8 @@ void sbitmap_add_wait_queue(struct sbitmap_queue *sbq,
 	if (!sbq_wait->sbq) {
 		sbq_wait->sbq = sbq;
 		atomic_inc(&sbq->ws_active);
+		add_wait_queue(&ws->wait, &sbq_wait->wait);
 	}
-	add_wait_queue(&ws->wait, &sbq_wait->wait);
 }
 EXPORT_SYMBOL_GPL(sbitmap_add_wait_queue);
 
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index c2cf2c311b7d..5813072bc589 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -311,7 +311,7 @@ int __sg_alloc_table(struct sg_table *table, unsigned int nents,
 			if (prv)
 				table->nents = ++table->orig_nents;
 
- 			return -ENOMEM;
+			return -ENOMEM;
 		}
 
 		sg_init_table(sg, alloc_size);
diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index ed717dd08ff3..81c69c08d1d1 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -83,15 +83,19 @@ static bool init_stack_slab(void **prealloc)
 		return true;
 	if (stack_slabs[depot_index] == NULL) {
 		stack_slabs[depot_index] = *prealloc;
+		*prealloc = NULL;
 	} else {
-		stack_slabs[depot_index + 1] = *prealloc;
+		/* If this is the last depot slab, do not touch the next one. */
+		if (depot_index + 1 < STACK_ALLOC_MAX_SLABS) {
+			stack_slabs[depot_index + 1] = *prealloc;
+			*prealloc = NULL;
+		}
 		/*
 		 * This smp_store_release pairs with smp_load_acquire() from
 		 * |next_slab_inited| above and in stack_depot_save().
 		 */
 		smp_store_release(&next_slab_inited, 1);
 	}
-	*prealloc = NULL;
 	return true;
 }
 
diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c
index dccb95af6003..706020b06617 100644
--- a/lib/strncpy_from_user.c
+++ b/lib/strncpy_from_user.c
@@ -30,13 +30,6 @@ static inline long do_strncpy_from_user(char *dst, const char __user *src,
 	const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
 	unsigned long res = 0;
 
-	/*
-	 * Truncate 'max' to the user-specified limit, so that
-	 * we only have one limit we need to check in the loop
-	 */
-	if (max > count)
-		max = count;
-
 	if (IS_UNALIGNED(src, dst))
 		goto byte_at_a_time;
 
@@ -114,6 +107,13 @@ long strncpy_from_user(char *dst, const char __user *src, long count)
 		unsigned long max = max_addr - src_addr;
 		long retval;
 
+		/*
+		 * Truncate 'max' to the user-specified limit, so that
+		 * we only have one limit we need to check in the loop
+		 */
+		if (max > count)
+			max = count;
+
 		kasan_check_write(dst, count);
 		check_object_size(dst, count, false);
 		if (user_access_begin(src, max)) {
diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c
index 6c0005d5dd5c..41670d4a5816 100644
--- a/lib/strnlen_user.c
+++ b/lib/strnlen_user.c
@@ -27,13 +27,6 @@ static inline long do_strnlen_user(const char __user *src, unsigned long count,
 	unsigned long c;
 
 	/*
-	 * Truncate 'max' to the user-specified limit, so that
-	 * we only have one limit we need to check in the loop
-	 */
-	if (max > count)
-		max = count;
-
-	/*
 	 * Do everything aligned. But that means that we
 	 * need to also expand the maximum..
 	 */
@@ -109,6 +102,13 @@ long strnlen_user(const char __user *str, long count)
 		unsigned long max = max_addr - src_addr;
 		long retval;
 
+		/*
+		 * Truncate 'max' to the user-specified limit, so that
+		 * we only have one limit we need to check in the loop
+		 */
+		if (max > count)
+			max = count;
+
 		if (user_access_begin(str, max)) {
 			retval = do_strnlen_user(str, count, max);
 			user_access_end();
diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 49cc4d570a40..bd3d9ef7d39e 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -157,6 +157,7 @@ static noinline void __init kmalloc_oob_krealloc_more(void)
 	if (!ptr1 || !ptr2) {
 		pr_err("Allocation failed\n");
 		kfree(ptr1);
+		kfree(ptr2);
 		return;
 	}
 
diff --git a/lib/test_xarray.c b/lib/test_xarray.c
index 7df4f7f395bf..55c14e8c8859 100644
--- a/lib/test_xarray.c
+++ b/lib/test_xarray.c
@@ -2,6 +2,7 @@
 /*
  * test_xarray.c: Test the XArray API
  * Copyright (c) 2017-2018 Microsoft Corporation
+ * Copyright (c) 2019-2020 Oracle
  * Author: Matthew Wilcox <willy@infradead.org>
  */
 
@@ -902,28 +903,34 @@ static noinline void check_store_iter(struct xarray *xa)
 	XA_BUG_ON(xa, !xa_empty(xa));
 }
 
-static noinline void check_multi_find(struct xarray *xa)
+static noinline void check_multi_find_1(struct xarray *xa, unsigned order)
 {
 #ifdef CONFIG_XARRAY_MULTI
+	unsigned long multi = 3 << order;
+	unsigned long next = 4 << order;
 	unsigned long index;
 
-	xa_store_order(xa, 12, 2, xa_mk_value(12), GFP_KERNEL);
-	XA_BUG_ON(xa, xa_store_index(xa, 16, GFP_KERNEL) != NULL);
+	xa_store_order(xa, multi, order, xa_mk_value(multi), GFP_KERNEL);
+	XA_BUG_ON(xa, xa_store_index(xa, next, GFP_KERNEL) != NULL);
+	XA_BUG_ON(xa, xa_store_index(xa, next + 1, GFP_KERNEL) != NULL);
 
 	index = 0;
 	XA_BUG_ON(xa, xa_find(xa, &index, ULONG_MAX, XA_PRESENT) !=
-			xa_mk_value(12));
-	XA_BUG_ON(xa, index != 12);
-	index = 13;
+			xa_mk_value(multi));
+	XA_BUG_ON(xa, index != multi);
+	index = multi + 1;
 	XA_BUG_ON(xa, xa_find(xa, &index, ULONG_MAX, XA_PRESENT) !=
-			xa_mk_value(12));
-	XA_BUG_ON(xa, (index < 12) || (index >= 16));
+			xa_mk_value(multi));
+	XA_BUG_ON(xa, (index < multi) || (index >= next));
 	XA_BUG_ON(xa, xa_find_after(xa, &index, ULONG_MAX, XA_PRESENT) !=
-			xa_mk_value(16));
-	XA_BUG_ON(xa, index != 16);
-
-	xa_erase_index(xa, 12);
-	xa_erase_index(xa, 16);
+			xa_mk_value(next));
+	XA_BUG_ON(xa, index != next);
+	XA_BUG_ON(xa, xa_find_after(xa, &index, next, XA_PRESENT) != NULL);
+	XA_BUG_ON(xa, index != next);
+
+	xa_erase_index(xa, multi);
+	xa_erase_index(xa, next);
+	xa_erase_index(xa, next + 1);
 	XA_BUG_ON(xa, !xa_empty(xa));
 #endif
 }
@@ -1046,12 +1053,33 @@ static noinline void check_find_3(struct xarray *xa)
 	xa_destroy(xa);
 }
 
+static noinline void check_find_4(struct xarray *xa)
+{
+	unsigned long index = 0;
+	void *entry;
+
+	xa_store_index(xa, ULONG_MAX, GFP_KERNEL);
+
+	entry = xa_find_after(xa, &index, ULONG_MAX, XA_PRESENT);
+	XA_BUG_ON(xa, entry != xa_mk_index(ULONG_MAX));
+
+	entry = xa_find_after(xa, &index, ULONG_MAX, XA_PRESENT);
+	XA_BUG_ON(xa, entry);
+
+	xa_erase_index(xa, ULONG_MAX);
+}
+
 static noinline void check_find(struct xarray *xa)
 {
+	unsigned i;
+
 	check_find_1(xa);
 	check_find_2(xa);
 	check_find_3(xa);
-	check_multi_find(xa);
+	check_find_4(xa);
+
+	for (i = 2; i < 10; i++)
+		check_multi_find_1(xa, i);
 	check_multi_find_2(xa);
 }
 
@@ -1132,6 +1160,27 @@ static noinline void check_move_tiny(struct xarray *xa)
 	XA_BUG_ON(xa, !xa_empty(xa));
 }
 
+static noinline void check_move_max(struct xarray *xa)
+{
+	XA_STATE(xas, xa, 0);
+
+	xa_store_index(xa, ULONG_MAX, GFP_KERNEL);
+	rcu_read_lock();
+	XA_BUG_ON(xa, xas_find(&xas, ULONG_MAX) != xa_mk_index(ULONG_MAX));
+	XA_BUG_ON(xa, xas_find(&xas, ULONG_MAX) != NULL);
+	rcu_read_unlock();
+
+	xas_set(&xas, 0);
+	rcu_read_lock();
+	XA_BUG_ON(xa, xas_find(&xas, ULONG_MAX) != xa_mk_index(ULONG_MAX));
+	xas_pause(&xas);
+	XA_BUG_ON(xa, xas_find(&xas, ULONG_MAX) != NULL);
+	rcu_read_unlock();
+
+	xa_erase_index(xa, ULONG_MAX);
+	XA_BUG_ON(xa, !xa_empty(xa));
+}
+
 static noinline void check_move_small(struct xarray *xa, unsigned long idx)
 {
 	XA_STATE(xas, xa, 0);
@@ -1240,6 +1289,7 @@ static noinline void check_move(struct xarray *xa)
 	xa_destroy(xa);
 
 	check_move_tiny(xa);
+	check_move_max(xa);
 
 	for (i = 0; i < 16; i++)
 		check_move_small(xa, 1UL << i);
diff --git a/lib/ubsan.c b/lib/ubsan.c
index e7d31735950d..f007a406f89c 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -140,25 +140,21 @@ static void val_to_string(char *str, size_t size, struct type_descriptor *type,
 	}
 }
 
-static DEFINE_SPINLOCK(report_lock);
-
-static void ubsan_prologue(struct source_location *location,
-			unsigned long *flags)
+static void ubsan_prologue(struct source_location *location)
 {
 	current->in_ubsan++;
-	spin_lock_irqsave(&report_lock, *flags);
 
 	pr_err("========================================"
 		"========================================\n");
 	print_source_location("UBSAN: Undefined behaviour in", location);
 }
 
-static void ubsan_epilogue(unsigned long *flags)
+static void ubsan_epilogue(void)
 {
 	dump_stack();
 	pr_err("========================================"
 		"========================================\n");
-	spin_unlock_irqrestore(&report_lock, *flags);
+
 	current->in_ubsan--;
 }
 
@@ -167,14 +163,13 @@ static void handle_overflow(struct overflow_data *data, void *lhs,
 {
 
 	struct type_descriptor *type = data->type;
-	unsigned long flags;
 	char lhs_val_str[VALUE_LENGTH];
 	char rhs_val_str[VALUE_LENGTH];
 
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 
 	val_to_string(lhs_val_str, sizeof(lhs_val_str), type, lhs);
 	val_to_string(rhs_val_str, sizeof(rhs_val_str), type, rhs);
@@ -186,7 +181,7 @@ static void handle_overflow(struct overflow_data *data, void *lhs,
 		rhs_val_str,
 		type->type_name);
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 
 void __ubsan_handle_add_overflow(struct overflow_data *data,
@@ -214,20 +209,19 @@ EXPORT_SYMBOL(__ubsan_handle_mul_overflow);
 void __ubsan_handle_negate_overflow(struct overflow_data *data,
 				void *old_val)
 {
-	unsigned long flags;
 	char old_val_str[VALUE_LENGTH];
 
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 
 	val_to_string(old_val_str, sizeof(old_val_str), data->type, old_val);
 
 	pr_err("negation of %s cannot be represented in type %s:\n",
 		old_val_str, data->type->type_name);
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 EXPORT_SYMBOL(__ubsan_handle_negate_overflow);
 
@@ -235,13 +229,12 @@ EXPORT_SYMBOL(__ubsan_handle_negate_overflow);
 void __ubsan_handle_divrem_overflow(struct overflow_data *data,
 				void *lhs, void *rhs)
 {
-	unsigned long flags;
 	char rhs_val_str[VALUE_LENGTH];
 
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 
 	val_to_string(rhs_val_str, sizeof(rhs_val_str), data->type, rhs);
 
@@ -251,58 +244,52 @@ void __ubsan_handle_divrem_overflow(struct overflow_data *data,
 	else
 		pr_err("division by zero\n");
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 EXPORT_SYMBOL(__ubsan_handle_divrem_overflow);
 
 static void handle_null_ptr_deref(struct type_mismatch_data_common *data)
 {
-	unsigned long flags;
-
 	if (suppress_report(data->location))
 		return;
 
-	ubsan_prologue(data->location, &flags);
+	ubsan_prologue(data->location);
 
 	pr_err("%s null pointer of type %s\n",
 		type_check_kinds[data->type_check_kind],
 		data->type->type_name);
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 
 static void handle_misaligned_access(struct type_mismatch_data_common *data,
 				unsigned long ptr)
 {
-	unsigned long flags;
-
 	if (suppress_report(data->location))
 		return;
 
-	ubsan_prologue(data->location, &flags);
+	ubsan_prologue(data->location);
 
 	pr_err("%s misaligned address %p for type %s\n",
 		type_check_kinds[data->type_check_kind],
 		(void *)ptr, data->type->type_name);
 	pr_err("which requires %ld byte alignment\n", data->alignment);
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 
 static void handle_object_size_mismatch(struct type_mismatch_data_common *data,
 					unsigned long ptr)
 {
-	unsigned long flags;
-
 	if (suppress_report(data->location))
 		return;
 
-	ubsan_prologue(data->location, &flags);
+	ubsan_prologue(data->location);
 	pr_err("%s address %p with insufficient space\n",
 		type_check_kinds[data->type_check_kind],
 		(void *) ptr);
 	pr_err("for an object of type %s\n", data->type->type_name);
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 
 static void ubsan_type_mismatch_common(struct type_mismatch_data_common *data,
@@ -351,34 +338,33 @@ EXPORT_SYMBOL(__ubsan_handle_type_mismatch_v1);
 
 void __ubsan_handle_out_of_bounds(struct out_of_bounds_data *data, void *index)
 {
-	unsigned long flags;
 	char index_str[VALUE_LENGTH];
 
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 
 	val_to_string(index_str, sizeof(index_str), data->index_type, index);
 	pr_err("index %s is out of range for type %s\n", index_str,
 		data->array_type->type_name);
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 EXPORT_SYMBOL(__ubsan_handle_out_of_bounds);
 
 void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
 					void *lhs, void *rhs)
 {
-	unsigned long flags;
 	struct type_descriptor *rhs_type = data->rhs_type;
 	struct type_descriptor *lhs_type = data->lhs_type;
 	char rhs_str[VALUE_LENGTH];
 	char lhs_str[VALUE_LENGTH];
+	unsigned long ua_flags = user_access_save();
 
 	if (suppress_report(&data->location))
-		return;
+		goto out;
 
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 
 	val_to_string(rhs_str, sizeof(rhs_str), rhs_type, rhs);
 	val_to_string(lhs_str, sizeof(lhs_str), lhs_type, lhs);
@@ -401,18 +387,18 @@ void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
 			lhs_str, rhs_str,
 			lhs_type->type_name);
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
+out:
+	user_access_restore(ua_flags);
 }
 EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds);
 
 
 void __ubsan_handle_builtin_unreachable(struct unreachable_data *data)
 {
-	unsigned long flags;
-
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 	pr_err("calling __builtin_unreachable()\n");
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 	panic("can't return from __builtin_unreachable()");
 }
 EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);
@@ -420,19 +406,18 @@ EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);
 void __ubsan_handle_load_invalid_value(struct invalid_value_data *data,
 				void *val)
 {
-	unsigned long flags;
 	char val_str[VALUE_LENGTH];
 
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location, &flags);
+	ubsan_prologue(&data->location);
 
 	val_to_string(val_str, sizeof(val_str), data->type, val);
 
 	pr_err("load of value %s is not a valid value for type %s\n",
 		val_str, data->type->type_name);
 
-	ubsan_epilogue(&flags);
+	ubsan_epilogue();
 }
 EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
diff --git a/lib/xarray.c b/lib/xarray.c
index 1237c213f52b..1d9fab7db8da 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -1,7 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
  * XArray implementation
- * Copyright (c) 2017 Microsoft Corporation
+ * Copyright (c) 2017-2018 Microsoft Corporation
+ * Copyright (c) 2018-2020 Oracle
  * Author: Matthew Wilcox <willy@infradead.org>
  */
 
@@ -967,6 +968,7 @@ void xas_pause(struct xa_state *xas)
 	if (xas_invalid(xas))
 		return;
 
+	xas->xa_node = XAS_RESTART;
 	if (node) {
 		unsigned int offset = xas->xa_offset;
 		while (++offset < XA_CHUNK_SIZE) {
@@ -974,10 +976,11 @@ void xas_pause(struct xa_state *xas)
 				break;
 		}
 		xas->xa_index += (offset - xas->xa_offset) << node->shift;
+		if (xas->xa_index == 0)
+			xas->xa_node = XAS_BOUNDS;
 	} else {
 		xas->xa_index++;
 	}
-	xas->xa_node = XAS_RESTART;
 }
 EXPORT_SYMBOL_GPL(xas_pause);
 
@@ -1079,13 +1082,15 @@ void *xas_find(struct xa_state *xas, unsigned long max)
 {
 	void *entry;
 
-	if (xas_error(xas))
+	if (xas_error(xas) || xas->xa_node == XAS_BOUNDS)
 		return NULL;
+	if (xas->xa_index > max)
+		return set_bounds(xas);
 
 	if (!xas->xa_node) {
 		xas->xa_index = 1;
 		return set_bounds(xas);
-	} else if (xas_top(xas->xa_node)) {
+	} else if (xas->xa_node == XAS_RESTART) {
 		entry = xas_load(xas);
 		if (entry || xas_not_node(xas->xa_node))
 			return entry;
@@ -1150,6 +1155,8 @@ void *xas_find_marked(struct xa_state *xas, unsigned long max, xa_mark_t mark)
 
 	if (xas_error(xas))
 		return NULL;
+	if (xas->xa_index > max)
+		goto max;
 
 	if (!xas->xa_node) {
 		xas->xa_index = 1;
@@ -1824,6 +1831,17 @@ void *xa_find(struct xarray *xa, unsigned long *indexp,
 }
 EXPORT_SYMBOL(xa_find);
 
+static bool xas_sibling(struct xa_state *xas)
+{
+	struct xa_node *node = xas->xa_node;
+	unsigned long mask;
+
+	if (!node)
+		return false;
+	mask = (XA_CHUNK_SIZE << node->shift) - 1;
+	return (xas->xa_index & mask) > (xas->xa_offset << node->shift);
+}
+
 /**
  * xa_find_after() - Search the XArray for a present entry.
  * @xa: XArray.
@@ -1847,21 +1865,20 @@ void *xa_find_after(struct xarray *xa, unsigned long *indexp,
 	XA_STATE(xas, xa, *indexp + 1);
 	void *entry;
 
+	if (xas.xa_index == 0)
+		return NULL;
+
 	rcu_read_lock();
 	for (;;) {
 		if ((__force unsigned int)filter < XA_MAX_MARKS)
 			entry = xas_find_marked(&xas, max, filter);
 		else
 			entry = xas_find(&xas, max);
-		if (xas.xa_node == XAS_BOUNDS)
+
+		if (xas_invalid(&xas))
 			break;
-		if (xas.xa_shift) {
-			if (xas.xa_index & ((1UL << xas.xa_shift) - 1))
-				continue;
-		} else {
-			if (xas.xa_offset < (xas.xa_index & XA_CHUNK_MASK))
-				continue;
-		}
+		if (xas_sibling(&xas))
+			continue;
 		if (!xas_retry(&xas, entry))
 			break;
 	}