Merge tag 'driver-core-6.13-rc7' of git://git.kernel.org/pub/scm/linu…

…x/kernel/git/gregkh/driver-core

Pull driver core and debugfs fixes from Greg KH:
 "Here are some small driver core and debugfs fixes that resolve some
  reported problems:

   - debugfs runtime error reporting fixes

   - topology cpumask race-condition fix

   - MAINTAINERS file email update

  All of these have been in linux-next this week with no reported
  issues"

* tag 'driver-core-6.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  fs: debugfs: fix open proxy for unsafe files
  MAINTAINERS: align Danilo's maintainer entries
  topology: Keep the cpumask unchanged when printing cpumap
  debugfs: fix missing mutex_destroy() in short_fops case
  fs: debugfs: differentiate short fops with proxy ops

drivers/base/topology.c

@@ -27,19 +27,35 @@ static ssize_t name##_read(struct file *file, struct kobject *kobj,		\
 			   loff_t off, size_t count)				\
 {										\
 	struct device *dev = kobj_to_dev(kobj);                                 \
+	cpumask_var_t mask;							\
+	ssize_t n;								\
 										\
-	return cpumap_print_bitmask_to_buf(buf, topology_##mask(dev->id),	\
-					   off, count);                         \
+	if (!alloc_cpumask_var(&mask, GFP_KERNEL))				\
+		return -ENOMEM;							\
+										\
+	cpumask_copy(mask, topology_##mask(dev->id));				\
+	n = cpumap_print_bitmask_to_buf(buf, mask, off, count);			\
+	free_cpumask_var(mask);							\
+										\
+	return n;								\
 }										\
 										\
 static ssize_t name##_list_read(struct file *file, struct kobject *kobj,	\
 				const struct bin_attribute *attr, char *buf,	\
 				loff_t off, size_t count)			\
 {										\
 	struct device *dev = kobj_to_dev(kobj);					\
+	cpumask_var_t mask;							\
+	ssize_t n;								\
+										\
+	if (!alloc_cpumask_var(&mask, GFP_KERNEL))				\
+		return -ENOMEM;							\
+										\
+	cpumask_copy(mask, topology_##mask(dev->id));				\
+	n = cpumap_print_list_to_buf(buf, mask, off, count);			\
+	free_cpumask_var(mask);							\
 										\
-	return cpumap_print_list_to_buf(buf, topology_##mask(dev->id),		\
-					off, count);				\
+	return n;								\
 }
 
 define_id_show_func(physical_package_id, "%d");

fs/debugfs/file.c

@@ -64,22 +64,13 @@ const struct file_operations *debugfs_real_fops(const struct file *filp)
 }
 EXPORT_SYMBOL_GPL(debugfs_real_fops);
 
-/**
- * debugfs_file_get - mark the beginning of file data access
- * @dentry: the dentry object whose data is being accessed.
- *
- * Up to a matching call to debugfs_file_put(), any successive call
- * into the file removing functions debugfs_remove() and
- * debugfs_remove_recursive() will block. Since associated private
- * file data may only get freed after a successful return of any of
- * the removal functions, you may safely access it after a successful
- * call to debugfs_file_get() without worrying about lifetime issues.
- *
- * If -%EIO is returned, the file has already been removed and thus,
- * it is not safe to access any of its data. If, on the other hand,
- * it is allowed to access the file data, zero is returned.
- */
-int debugfs_file_get(struct dentry *dentry)
+enum dbgfs_get_mode {
+	DBGFS_GET_ALREADY,
+	DBGFS_GET_REGULAR,
+	DBGFS_GET_SHORT,
+};
+
+static int __debugfs_file_get(struct dentry *dentry, enum dbgfs_get_mode mode)
 {
 	struct debugfs_fsdata *fsd;
 	void *d_fsd;
@@ -96,15 +87,17 @@ int debugfs_file_get(struct dentry *dentry)
 	if (!((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) {
 		fsd = d_fsd;
 	} else {
+		if (WARN_ON(mode == DBGFS_GET_ALREADY))
+			return -EINVAL;
+
 		fsd = kmalloc(sizeof(*fsd), GFP_KERNEL);
 		if (!fsd)
 			return -ENOMEM;
 
-		if ((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_SHORT_FOPS_BIT) {
+		if (mode == DBGFS_GET_SHORT) {
 			fsd->real_fops = NULL;
 			fsd->short_fops = (void *)((unsigned long)d_fsd &
-						~(DEBUGFS_FSDATA_IS_REAL_FOPS_BIT |
-						  DEBUGFS_FSDATA_IS_SHORT_FOPS_BIT));
+						~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT);
 		} else {
 			fsd->real_fops = (void *)((unsigned long)d_fsd &
 						~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT);
@@ -138,6 +131,26 @@ int debugfs_file_get(struct dentry *dentry)
 
 	return 0;
 }
+
+/**
+ * debugfs_file_get - mark the beginning of file data access
+ * @dentry: the dentry object whose data is being accessed.
+ *
+ * Up to a matching call to debugfs_file_put(), any successive call
+ * into the file removing functions debugfs_remove() and
+ * debugfs_remove_recursive() will block. Since associated private
+ * file data may only get freed after a successful return of any of
+ * the removal functions, you may safely access it after a successful
+ * call to debugfs_file_get() without worrying about lifetime issues.
+ *
+ * If -%EIO is returned, the file has already been removed and thus,
+ * it is not safe to access any of its data. If, on the other hand,
+ * it is allowed to access the file data, zero is returned.
+ */
+int debugfs_file_get(struct dentry *dentry)
+{
+	return __debugfs_file_get(dentry, DBGFS_GET_ALREADY);
+}
 EXPORT_SYMBOL_GPL(debugfs_file_get);
 
 /**
@@ -267,7 +280,7 @@ static int open_proxy_open(struct inode *inode, struct file *filp)
 	const struct file_operations *real_fops = NULL;
 	int r;
 
-	r = debugfs_file_get(dentry);
+	r = __debugfs_file_get(dentry, DBGFS_GET_REGULAR);
 	if (r)
 		return r == -EIO ? -ENOENT : r;
 
@@ -424,15 +437,16 @@ static void __full_proxy_fops_init(struct file_operations *proxy_fops,
 		proxy_fops->unlocked_ioctl = full_proxy_unlocked_ioctl;
 }
 
-static int full_proxy_open(struct inode *inode, struct file *filp)
+static int full_proxy_open(struct inode *inode, struct file *filp,
+			   enum dbgfs_get_mode mode)
 {
 	struct dentry *dentry = F_DENTRY(filp);
 	const struct file_operations *real_fops;
 	struct file_operations *proxy_fops = NULL;
 	struct debugfs_fsdata *fsd;
 	int r;
 
-	r = debugfs_file_get(dentry);
+	r = __debugfs_file_get(dentry, mode);
 	if (r)
 		return r == -EIO ? -ENOENT : r;
 
@@ -491,8 +505,22 @@ static int full_proxy_open(struct inode *inode, struct file *filp)
 	return r;
 }
 
+static int full_proxy_open_regular(struct inode *inode, struct file *filp)
+{
+	return full_proxy_open(inode, filp, DBGFS_GET_REGULAR);
+}
+
 const struct file_operations debugfs_full_proxy_file_operations = {
-	.open = full_proxy_open,
+	.open = full_proxy_open_regular,
+};
+
+static int full_proxy_open_short(struct inode *inode, struct file *filp)
+{
+	return full_proxy_open(inode, filp, DBGFS_GET_SHORT);
+}
+
+const struct file_operations debugfs_full_short_proxy_file_operations = {
+	.open = full_proxy_open_short,
 };
 
 ssize_t debugfs_attr_read(struct file *file, char __user *buf,

fs/debugfs/inode.c

@@ -229,7 +229,7 @@ static void debugfs_release_dentry(struct dentry *dentry)
 		return;
 
 	/* check it wasn't a dir (no fsdata) or automount (no real_fops) */
-	if (fsd && fsd->real_fops) {
+	if (fsd && (fsd->real_fops || fsd->short_fops)) {
 		WARN_ON(!list_empty(&fsd->cancellations));
 		mutex_destroy(&fsd->cancellations_mtx);
 	}
@@ -455,8 +455,7 @@ struct dentry *debugfs_create_file_full(const char *name, umode_t mode,
 					const struct file_operations *fops)
 {
 	if (WARN_ON((unsigned long)fops &
-		    (DEBUGFS_FSDATA_IS_SHORT_FOPS_BIT |
-		     DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)))
+		    DEBUGFS_FSDATA_IS_REAL_FOPS_BIT))
 		return ERR_PTR(-EINVAL);
 
 	return __debugfs_create_file(name, mode, parent, data,
@@ -471,15 +470,13 @@ struct dentry *debugfs_create_file_short(const char *name, umode_t mode,
 					 const struct debugfs_short_fops *fops)
 {
 	if (WARN_ON((unsigned long)fops &
-		    (DEBUGFS_FSDATA_IS_SHORT_FOPS_BIT |
-		     DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)))
+		    DEBUGFS_FSDATA_IS_REAL_FOPS_BIT))
 		return ERR_PTR(-EINVAL);
 
 	return __debugfs_create_file(name, mode, parent, data,
-				fops ? &debugfs_full_proxy_file_operations :
+				fops ? &debugfs_full_short_proxy_file_operations :
 					&debugfs_noop_file_operations,
-				(const void *)((unsigned long)fops |
-					       DEBUGFS_FSDATA_IS_SHORT_FOPS_BIT));
+				fops);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_file_short);
 

fs/debugfs/internal.h

@@ -15,6 +15,7 @@ struct file_operations;
 extern const struct file_operations debugfs_noop_file_operations;
 extern const struct file_operations debugfs_open_proxy_file_operations;
 extern const struct file_operations debugfs_full_proxy_file_operations;
+extern const struct file_operations debugfs_full_short_proxy_file_operations;
 
 struct debugfs_fsdata {
 	const struct file_operations *real_fops;
@@ -40,11 +41,6 @@ struct debugfs_fsdata {
  * pointer gets its lowest bit set.
  */
 #define DEBUGFS_FSDATA_IS_REAL_FOPS_BIT BIT(0)
-/*
- * A dentry's ->d_fsdata, when pointing to real fops, is with
- * short fops instead of full fops.
- */
-#define DEBUGFS_FSDATA_IS_SHORT_FOPS_BIT BIT(1)
 
 /* Access BITS */
 #define DEBUGFS_ALLOW_API	BIT(0)