Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/s390/kernel/debug.c b/arch/s390/kernel/debug.c
index d374f9b..6d321f5 100644
--- a/arch/s390/kernel/debug.c
+++ b/arch/s390/kernel/debug.c
@@ -647,11 +647,23 @@
return 0; /* success */
}
-/*
- * debug_register_mode:
- * - Creates and initializes debug area for the caller
- * The mode parameter allows to specify access rights for the s390dbf files
- * - Returns handle for debug area
+/**
+ * debug_register_mode() - creates and initializes debug area.
+ *
+ * @name: Name of debug log (e.g. used for debugfs entry)
+ * @pages_per_area: Number of pages, which will be allocated per area
+ * @nr_areas: Number of debug areas
+ * @buf_size: Size of data area in each debug entry
+ * @mode: File mode for debugfs files. E.g. S_IRWXUGO
+ * @uid: User ID for debugfs files. Currently only 0 is supported.
+ * @gid: Group ID for debugfs files. Currently only 0 is supported.
+ *
+ * Return:
+ * - Handle for generated debug area
+ * - %NULL if register failed
+ *
+ * Allocates memory for a debug log.
+ * Must not be called within an interrupt handler.
*/
debug_info_t *debug_register_mode(const char *name, int pages_per_area,
int nr_areas, int buf_size, umode_t mode,
@@ -681,10 +693,21 @@
}
EXPORT_SYMBOL(debug_register_mode);
-/*
- * debug_register:
- * - creates and initializes debug area for the caller
- * - returns handle for debug area
+/**
+ * debug_register() - creates and initializes debug area with default file mode.
+ *
+ * @name: Name of debug log (e.g. used for debugfs entry)
+ * @pages_per_area: Number of pages, which will be allocated per area
+ * @nr_areas: Number of debug areas
+ * @buf_size: Size of data area in each debug entry
+ *
+ * Return:
+ * - Handle for generated debug area
+ * - %NULL if register failed
+ *
+ * Allocates memory for a debug log.
+ * The debugfs file mode access permissions are read and write for user.
+ * Must not be called within an interrupt handler.
*/
debug_info_t *debug_register(const char *name, int pages_per_area,
int nr_areas, int buf_size)
@@ -694,9 +717,13 @@
}
EXPORT_SYMBOL(debug_register);
-/*
- * debug_unregister:
- * - give back debug area
+/**
+ * debug_unregister() - give back debug area.
+ *
+ * @id: handle for debug log
+ *
+ * Return:
+ * none
*/
void debug_unregister(debug_info_t *id)
{
@@ -745,9 +772,14 @@
return rc;
}
-/*
- * debug_set_level:
- * - set actual debug level
+/**
+ * debug_set_level() - Sets new actual debug level if new_level is valid.
+ *
+ * @id: handle for debug log
+ * @new_level: new debug level
+ *
+ * Return:
+ * none
*/
void debug_set_level(debug_info_t *id, int new_level)
{
@@ -873,6 +905,14 @@
static struct ctl_table_header *s390dbf_sysctl_header;
+/**
+ * debug_stop_all() - stops the debug feature if stopping is allowed.
+ *
+ * Return:
+ * - none
+ *
+ * Currently used in case of a kernel oops.
+ */
void debug_stop_all(void)
{
if (debug_stoppable)
@@ -880,6 +920,17 @@
}
EXPORT_SYMBOL(debug_stop_all);
+/**
+ * debug_set_critical() - event/exception functions try lock instead of spin.
+ *
+ * Return:
+ * - none
+ *
+ * Currently used in case of stopping all CPUs but the current one.
+ * Once in this state, functions to write a debug entry for an
+ * event or exception no longer spin on the debug area lock,
+ * but only try to get it and fail if they do not get the lock.
+ */
void debug_set_critical(void)
{
debug_critical = 1;
@@ -1036,8 +1087,16 @@
}
EXPORT_SYMBOL(__debug_sprintf_exception);
-/*
- * debug_register_view:
+/**
+ * debug_register_view() - registers new debug view and creates debugfs
+ * dir entry
+ *
+ * @id: handle for debug log
+ * @view: pointer to debug view struct
+ *
+ * Return:
+ * - 0 : ok
+ * - < 0: Error
*/
int debug_register_view(debug_info_t *id, struct debug_view *view)
{
@@ -1056,12 +1115,6 @@
mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
id, &debug_file_ops);
- if (!pde) {
- pr_err("Registering view %s/%s failed due to out of "
- "memory\n", id->name, view->name);
- rc = -1;
- goto out;
- }
spin_lock_irqsave(&id->lock, flags);
for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
if (!id->views[i])
@@ -1083,8 +1136,16 @@
}
EXPORT_SYMBOL(debug_register_view);
-/*
- * debug_unregister_view:
+/**
+ * debug_unregister_view() - unregisters debug view and removes debugfs
+ * dir entry
+ *
+ * @id: handle for debug log
+ * @view: pointer to debug view struct
+ *
+ * Return:
+ * - 0 : ok
+ * - < 0: Error
*/
int debug_unregister_view(debug_info_t *id, struct debug_view *view)
{