Merge tag 'regmap-fix-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap fixes from Mark Brown:
 "Two issues here - one is a fix for use after free issues in the case
  where a regmap overrides its name using something dynamically
  generated, the other is that we weren't handling access checks
  non-incrementing I/O on registers within paged register regions
  correctly resulting in spurious errors.

  Both of these are quite rare but serious if they occur"

* tag 'regmap-fix-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: fix page selection for noinc writes
  regmap: fix page selection for noinc reads
  regmap: debugfs: Add back in erroneously removed initialisation of ret
  regmap: debugfs: Fix handling of name string for debugfs init delays

drivers/base/regmap/internal.h

@@ -217,7 +217,7 @@ struct regmap_field {
 
 #ifdef CONFIG_DEBUG_FS
 extern void regmap_debugfs_initcall(void);
-extern void regmap_debugfs_init(struct regmap *map, const char *name);
+extern void regmap_debugfs_init(struct regmap *map);
 extern void regmap_debugfs_exit(struct regmap *map);
 
 static inline void regmap_debugfs_disable(struct regmap *map)
@@ -227,7 +227,7 @@ static inline void regmap_debugfs_disable(struct regmap *map)
 
 #else
 static inline void regmap_debugfs_initcall(void) { }
-static inline void regmap_debugfs_init(struct regmap *map, const char *name) { }
+static inline void regmap_debugfs_init(struct regmap *map) { }
 static inline void regmap_debugfs_exit(struct regmap *map) { }
 static inline void regmap_debugfs_disable(struct regmap *map) { }
 #endif
@@ -259,7 +259,7 @@ bool regcache_set_val(struct regmap *map, void *base, unsigned int idx,
 int regcache_lookup_reg(struct regmap *map, unsigned int reg);
 
 int _regmap_raw_write(struct regmap *map, unsigned int reg,
-		      const void *val, size_t val_len);
+		      const void *val, size_t val_len, bool noinc);
 
 void regmap_async_complete_cb(struct regmap_async *async, int ret);
 

drivers/base/regmap/regcache.c

@@ -717,7 +717,7 @@ static int regcache_sync_block_raw_flush(struct regmap *map, const void **data,
 
 	map->cache_bypass = true;
 
-	ret = _regmap_raw_write(map, base, *data, count * val_bytes);
+	ret = _regmap_raw_write(map, base, *data, count * val_bytes, false);
 	if (ret)
 		dev_err(map->dev, "Unable to sync registers %#x-%#x. %d\n",
 			base, cur - map->reg_stride, ret);

drivers/base/regmap/regmap-debugfs.c

@@ -17,7 +17,6 @@
 
 struct regmap_debugfs_node {
 	struct regmap *map;
-	const char *name;
 	struct list_head link;
 };
 
@@ -544,11 +543,12 @@ static const struct file_operations regmap_cache_bypass_fops = {
 	.write = regmap_cache_bypass_write_file,
 };
 
-void regmap_debugfs_init(struct regmap *map, const char *name)
+void regmap_debugfs_init(struct regmap *map)
 {
 	struct rb_node *next;
 	struct regmap_range_node *range_node;
 	const char *devname = "dummy";
+	const char *name = map->name;
 
 	/*
 	 * Userspace can initiate reads from the hardware over debugfs.
@@ -569,7 +569,6 @@ void regmap_debugfs_init(struct regmap *map, const char *name)
 		if (!node)
 			return;
 		node->map = map;
-		node->name = name;
 		mutex_lock(&regmap_debugfs_early_lock);
 		list_add(&node->link, &regmap_debugfs_early_list);
 		mutex_unlock(&regmap_debugfs_early_lock);
@@ -679,7 +678,7 @@ void regmap_debugfs_initcall(void)
 
 	mutex_lock(&regmap_debugfs_early_lock);
 	list_for_each_entry_safe(node, tmp, &regmap_debugfs_early_list, link) {
-		regmap_debugfs_init(node->map, node->name);
+		regmap_debugfs_init(node->map);
 		list_del(&node->link);
 		kfree(node);
 	}

drivers/base/regmap/regmap.c

@@ -581,14 +581,34 @@ static void regmap_range_exit(struct regmap *map)
 	kfree(map->selector_work_buf);
 }
 
+static int regmap_set_name(struct regmap *map, const struct regmap_config *config)
+{
+	if (config->name) {
+		const char *name = kstrdup_const(config->name, GFP_KERNEL);
+
+		if (!name)
+			return -ENOMEM;
+
+		kfree_const(map->name);
+		map->name = name;
+	}
+
+	return 0;
+}
+
 int regmap_attach_dev(struct device *dev, struct regmap *map,
 		      const struct regmap_config *config)
 {
 	struct regmap **m;
+	int ret;
 
 	map->dev = dev;
 
-	regmap_debugfs_init(map, config->name);
+	ret = regmap_set_name(map, config);
+	if (ret)
+		return ret;
+
+	regmap_debugfs_init(map);
 
 	/* Add a devres resource for dev_get_regmap() */
 	m = devres_alloc(dev_get_regmap_release, sizeof(*m), GFP_KERNEL);
@@ -687,13 +707,9 @@ struct regmap *__regmap_init(struct device *dev,
 		goto err;
 	}
 
-	if (config->name) {
-		map->name = kstrdup_const(config->name, GFP_KERNEL);
-		if (!map->name) {
-			ret = -ENOMEM;
-			goto err_map;
-		}
-	}
+	ret = regmap_set_name(map, config);
+	if (ret)
+		goto err_map;
 
 	if (config->disable_locking) {
 		map->lock = map->unlock = regmap_lock_unlock_none;
@@ -1137,7 +1153,7 @@ struct regmap *__regmap_init(struct device *dev,
 		if (ret != 0)
 			goto err_regcache;
 	} else {
-		regmap_debugfs_init(map, config->name);
+		regmap_debugfs_init(map);
 	}
 
 	return map;
@@ -1297,6 +1313,8 @@ EXPORT_SYMBOL_GPL(regmap_field_free);
  */
 int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
 {
+	int ret;
+
 	regcache_exit(map);
 	regmap_debugfs_exit(map);
 
@@ -1309,7 +1327,11 @@ int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
 	map->readable_noinc_reg = config->readable_noinc_reg;
 	map->cache_type = config->cache_type;
 
-	regmap_debugfs_init(map, config->name);
+	ret = regmap_set_name(map, config);
+	if (ret)
+		return ret;
+
+	regmap_debugfs_init(map);
 
 	map->cache_bypass = false;
 	map->cache_only = false;
@@ -1464,7 +1486,7 @@ static void regmap_set_work_buf_flag_mask(struct regmap *map, int max_bytes,
 }
 
 static int _regmap_raw_write_impl(struct regmap *map, unsigned int reg,
-				  const void *val, size_t val_len)
+				  const void *val, size_t val_len, bool noinc)
 {
 	struct regmap_range_node *range;
 	unsigned long flags;
@@ -1523,7 +1545,7 @@ static int _regmap_raw_write_impl(struct regmap *map, unsigned int reg,
 				win_residue, val_len / map->format.val_bytes);
 			ret = _regmap_raw_write_impl(map, reg, val,
 						     win_residue *
-						     map->format.val_bytes);
+						     map->format.val_bytes, noinc);
 			if (ret != 0)
 				return ret;
 
@@ -1537,7 +1559,7 @@ static int _regmap_raw_write_impl(struct regmap *map, unsigned int reg,
 			win_residue = range->window_len - win_offset;
 		}
 
-		ret = _regmap_select_page(map, &reg, range, val_num);
+		ret = _regmap_select_page(map, &reg, range, noinc ? 1 : val_num);
 		if (ret != 0)
 			return ret;
 	}
@@ -1745,7 +1767,8 @@ static int _regmap_bus_raw_write(void *context, unsigned int reg,
 				      map->work_buf +
 				      map->format.reg_bytes +
 				      map->format.pad_bytes,
-				      map->format.val_bytes);
+				      map->format.val_bytes,
+				      false);
 }
 
 static inline void *_regmap_map_get_context(struct regmap *map)
@@ -1839,7 +1862,7 @@ int regmap_write_async(struct regmap *map, unsigned int reg, unsigned int val)
 EXPORT_SYMBOL_GPL(regmap_write_async);
 
 int _regmap_raw_write(struct regmap *map, unsigned int reg,
-		      const void *val, size_t val_len)
+		      const void *val, size_t val_len, bool noinc)
 {
 	size_t val_bytes = map->format.val_bytes;
 	size_t val_count = val_len / val_bytes;
@@ -1860,7 +1883,7 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg,
 
 	/* Write as many bytes as possible with chunk_size */
 	for (i = 0; i < chunk_count; i++) {
-		ret = _regmap_raw_write_impl(map, reg, val, chunk_bytes);
+		ret = _regmap_raw_write_impl(map, reg, val, chunk_bytes, noinc);
 		if (ret)
 			return ret;
 
@@ -1871,7 +1894,7 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg,
 
 	/* Write remaining bytes */
 	if (val_len)
-		ret = _regmap_raw_write_impl(map, reg, val, val_len);
+		ret = _regmap_raw_write_impl(map, reg, val, val_len, noinc);
 
 	return ret;
 }
@@ -1904,7 +1927,7 @@ int regmap_raw_write(struct regmap *map, unsigned int reg,
 
 	map->lock(map->lock_arg);
 
-	ret = _regmap_raw_write(map, reg, val, val_len);
+	ret = _regmap_raw_write(map, reg, val, val_len, false);
 
 	map->unlock(map->lock_arg);
 
@@ -1962,7 +1985,7 @@ int regmap_noinc_write(struct regmap *map, unsigned int reg,
 			write_len = map->max_raw_write;
 		else
 			write_len = val_len;
-		ret = _regmap_raw_write(map, reg, val, write_len);
+		ret = _regmap_raw_write(map, reg, val, write_len, true);
 		if (ret)
 			goto out_unlock;
 		val = ((u8 *)val) + write_len;
@@ -2439,7 +2462,7 @@ int regmap_raw_write_async(struct regmap *map, unsigned int reg,
 
 	map->async = true;
 
-	ret = _regmap_raw_write(map, reg, val, val_len);
+	ret = _regmap_raw_write(map, reg, val, val_len, false);
 
 	map->async = false;
 
@@ -2450,7 +2473,7 @@ int regmap_raw_write_async(struct regmap *map, unsigned int reg,
 EXPORT_SYMBOL_GPL(regmap_raw_write_async);
 
 static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
-			    unsigned int val_len)
+			    unsigned int val_len, bool noinc)
 {
 	struct regmap_range_node *range;
 	int ret;
@@ -2463,7 +2486,7 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 	range = _regmap_range_lookup(map, reg);
 	if (range) {
 		ret = _regmap_select_page(map, &reg, range,
-					  val_len / map->format.val_bytes);
+					  noinc ? 1 : val_len / map->format.val_bytes);
 		if (ret != 0)
 			return ret;
 	}
@@ -2501,7 +2524,7 @@ static int _regmap_bus_read(void *context, unsigned int reg,
 	if (!map->format.parse_val)
 		return -EINVAL;
 
-	ret = _regmap_raw_read(map, reg, work_val, map->format.val_bytes);
+	ret = _regmap_raw_read(map, reg, work_val, map->format.val_bytes, false);
 	if (ret == 0)
 		*val = map->format.parse_val(work_val);
 
@@ -2617,7 +2640,7 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 
 		/* Read bytes that fit into whole chunks */
 		for (i = 0; i < chunk_count; i++) {
-			ret = _regmap_raw_read(map, reg, val, chunk_bytes);
+			ret = _regmap_raw_read(map, reg, val, chunk_bytes, false);
 			if (ret != 0)
 				goto out;
 
@@ -2628,7 +2651,7 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 
 		/* Read remaining bytes */
 		if (val_len) {
-			ret = _regmap_raw_read(map, reg, val, val_len);
+			ret = _regmap_raw_read(map, reg, val, val_len, false);
 			if (ret != 0)
 				goto out;
 		}
@@ -2703,7 +2726,7 @@ int regmap_noinc_read(struct regmap *map, unsigned int reg,
 			read_len = map->max_raw_read;
 		else
 			read_len = val_len;
-		ret = _regmap_raw_read(map, reg, val, read_len);
+		ret = _regmap_raw_read(map, reg, val, read_len, true);
 		if (ret)
 			goto out_unlock;
 		val = ((u8 *)val) + read_len;