1 files changed, 389 insertions, 122 deletions

diff --git a/arch/s390/include/asm/debug.h b/arch/s390/include/asm/debug.h
index 188c5052a20a..6375276d94ea 100644
--- a/arch/s390/include/asm/debug.h
+++ b/arch/s390/include/asm/debug.h
@@ -1,232 +1,499 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  *   S/390 debug facility
  *
- *    Copyright IBM Corp. 1999, 2000
+ *    Copyright IBM Corp. 1999, 2020
  */
-#ifndef DEBUG_H
-#define DEBUG_H
+#ifndef _ASM_S390_DEBUG_H
+#define _ASM_S390_DEBUG_H
 
 #include <linux/string.h>
 #include <linux/spinlock.h>
 #include <linux/kernel.h>
 #include <linux/time.h>
-#include <uapi/asm/debug.h>
+#include <linux/refcount.h>
+#include <linux/fs.h>
+#include <linux/init.h>
 
-#define DEBUG_MAX_LEVEL            6  /* debug levels range from 0 to 6 */
-#define DEBUG_OFF_LEVEL            -1 /* level where debug is switched off */
-#define DEBUG_FLUSH_ALL            -1 /* parameter to flush all areas */
-#define DEBUG_MAX_VIEWS            10 /* max number of views in proc fs */
-#define DEBUG_MAX_NAME_LEN         64 /* max length for a debugfs file name */
-#define DEBUG_DEFAULT_LEVEL        3  /* initial debug level */
+#define DEBUG_MAX_LEVEL		   6  /* debug levels range from 0 to 6 */
+#define DEBUG_OFF_LEVEL		   -1 /* level where debug is switched off */
+#define DEBUG_FLUSH_ALL		   -1 /* parameter to flush all areas */
+#define DEBUG_MAX_VIEWS		   10 /* max number of views in proc fs */
+#define DEBUG_MAX_NAME_LEN	   64 /* max length for a debugfs file name */
+#define DEBUG_DEFAULT_LEVEL	   3  /* initial debug level */
 
 #define DEBUG_DIR_ROOT "s390dbf" /* name of debug root directory in proc fs */
 
-#define DEBUG_DATA(entry) (char*)(entry + 1) /* data is stored behind */
-                                             /* the entry information */
+#define DEBUG_DATA(entry) (char *)(entry + 1) /* data is stored behind */
+					      /* the entry information */
+
+#define __DEBUG_FEATURE_VERSION	   3  /* version of debug feature */
+
+struct __debug_entry {
+	unsigned long clock	: 60;
+	unsigned long exception	:  1;
+	unsigned long level	:  3;
+	void *caller;
+	unsigned short cpu;
+} __packed;
 
 typedef struct __debug_entry debug_entry_t;
 
 struct debug_view;
 
-typedef struct debug_info {	
-	struct debug_info* next;
-	struct debug_info* prev;
-	atomic_t ref_count;
-	spinlock_t lock;			
+typedef struct debug_info {
+	struct debug_info *next;
+	struct debug_info *prev;
+	refcount_t ref_count;
+	spinlock_t lock;
 	int level;
 	int nr_areas;
 	int pages_per_area;
 	int buf_size;
-	int entry_size;	
-	debug_entry_t*** areas;
+	int entry_size;
+	debug_entry_t ***areas;
 	int active_area;
 	int *active_pages;
 	int *active_entries;
-	struct dentry* debugfs_root_entry;
-	struct dentry* debugfs_entries[DEBUG_MAX_VIEWS];
-	struct debug_view* views[DEBUG_MAX_VIEWS];	
+	struct dentry *debugfs_root_entry;
+	struct dentry *debugfs_entries[DEBUG_MAX_VIEWS];
+	struct debug_view *views[DEBUG_MAX_VIEWS];
 	char name[DEBUG_MAX_NAME_LEN];
 	umode_t mode;
 } debug_info_t;
 
-typedef int (debug_header_proc_t) (debug_info_t* id,
-				   struct debug_view* view,
+typedef int (debug_header_proc_t) (debug_info_t *id,
+				   struct debug_view *view,
 				   int area,
-				   debug_entry_t* entry,
-				   char* out_buf);
-
-typedef int (debug_format_proc_t) (debug_info_t* id,
-				   struct debug_view* view, char* out_buf,
-				   const char* in_buf);
-typedef int (debug_prolog_proc_t) (debug_info_t* id,
-				   struct debug_view* view,
-				   char* out_buf);
-typedef int (debug_input_proc_t) (debug_info_t* id,
-				  struct debug_view* view,
-				  struct file* file,
+				   debug_entry_t *entry,
+				   char *out_buf, size_t out_buf_size);
+
+typedef int (debug_format_proc_t) (debug_info_t *id,
+				   struct debug_view *view, char *out_buf,
+				   size_t out_buf_size,
+				   const char *in_buf);
+typedef int (debug_prolog_proc_t) (debug_info_t *id,
+				   struct debug_view *view,
+				   char *out_buf, size_t out_buf_size);
+typedef int (debug_input_proc_t) (debug_info_t *id,
+				  struct debug_view *view,
+				  struct file *file,
 				  const char __user *user_buf,
-				  size_t in_buf_size, loff_t* offset);
+				  size_t in_buf_size, loff_t *offset);
 
-int debug_dflt_header_fn(debug_info_t* id, struct debug_view* view,
-		         int area, debug_entry_t* entry, char* out_buf);						
-				
+int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
+			 int area, debug_entry_t *entry,
+			 char *out_buf, size_t out_buf_size);
+
+#define DEBUG_SPRINTF_MAX_ARGS 10
+int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
+			    char *out_buf, size_t out_buf_size,
+			    const char *inbuf);
 struct debug_view {
 	char name[DEBUG_MAX_NAME_LEN];
-	debug_prolog_proc_t* prolog_proc;
-	debug_header_proc_t* header_proc;
-	debug_format_proc_t* format_proc;
-	debug_input_proc_t*  input_proc;
-	void*                private_data;
+	debug_prolog_proc_t *prolog_proc;
+	debug_header_proc_t *header_proc;
+	debug_format_proc_t *format_proc;
+	debug_input_proc_t  *input_proc;
+	void		    *private_data;
 };
 
 extern struct debug_view debug_hex_ascii_view;
-extern struct debug_view debug_raw_view;
 extern struct debug_view debug_sprintf_view;
 
 /* do NOT use the _common functions */
 
-debug_entry_t* debug_event_common(debug_info_t* id, int level, 
-                                  const void* data, int length);
+debug_entry_t *debug_event_common(debug_info_t *id, int level,
+				  const void *data, int length);
 
-debug_entry_t* debug_exception_common(debug_info_t* id, int level, 
-                                      const void* data, int length);
+debug_entry_t *debug_exception_common(debug_info_t *id, int level,
+				      const void *data, int length);
 
 /* Debug Feature API: */
 
 debug_info_t *debug_register(const char *name, int pages, int nr_areas,
-                             int buf_size);
+			     int buf_size);
 
 debug_info_t *debug_register_mode(const char *name, int pages, int nr_areas,
 				  int buf_size, umode_t mode, uid_t uid,
 				  gid_t gid);
 
-void debug_unregister(debug_info_t* id);
+ssize_t debug_dump(debug_info_t *id, struct debug_view *view,
+		   char *buf, size_t buf_size, bool reverse);
+
+void debug_unregister(debug_info_t *id);
 
-void debug_set_level(debug_info_t* id, int new_level);
+void debug_set_level(debug_info_t *id, int new_level);
 
 void debug_set_critical(void);
+
 void debug_stop_all(void);
 
-static inline debug_entry_t*
-debug_event(debug_info_t* id, int level, void* data, int length)
+/**
+ * debug_level_enabled() - Returns true if debug events for the specified
+ *			   level would be logged. Otherwise returns false.
+ *
+ * @id:		handle for debug log
+ * @level:	debug level
+ *
+ * Return:
+ * - %true if level is less or equal to the current debug level.
+ */
+static inline bool debug_level_enabled(debug_info_t *id, int level)
+{
+	return level <= id->level;
+}
+
+/**
+ * debug_event() - writes binary debug entry to active debug area
+ *		   (if level <= actual debug level)
+ *
+ * @id:		handle for debug log
+ * @level:	debug level
+ * @data:	pointer to data for debug entry
+ * @length:	length of data in bytes
+ *
+ * Return:
+ * - Address of written debug entry
+ * - %NULL if error
+ */
+static inline debug_entry_t *debug_event(debug_info_t *id, int level,
+					 void *data, int length)
 {
 	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
 		return NULL;
-        return debug_event_common(id,level,data,length);
+	return debug_event_common(id, level, data, length);
 }
 
-static inline debug_entry_t*
-debug_int_event(debug_info_t* id, int level, unsigned int tag)
+/**
+ * debug_int_event() - writes unsigned integer debug entry to active debug area
+ *		       (if level <= actual debug level)
+ *
+ * @id:		handle for debug log
+ * @level:	debug level
+ * @tag:	integer value for debug entry
+ *
+ * Return:
+ * - Address of written debug entry
+ * - %NULL if error
+ */
+static inline debug_entry_t *debug_int_event(debug_info_t *id, int level,
+					     unsigned int tag)
 {
-        unsigned int t=tag;
+	unsigned int t = tag;
+
 	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
 		return NULL;
-        return debug_event_common(id,level,&t,sizeof(unsigned int));
+	return debug_event_common(id, level, &t, sizeof(unsigned int));
 }
 
-static inline debug_entry_t *
-debug_long_event (debug_info_t* id, int level, unsigned long tag)
+/**
+ * debug_long_event() - writes unsigned long debug entry to active debug area
+ *		       (if level <= actual debug level)
+ *
+ * @id:		handle for debug log
+ * @level:	debug level
+ * @tag:	long integer value for debug entry
+ *
+ * Return:
+ * - Address of written debug entry
+ * - %NULL if error
+ */
+static inline debug_entry_t *debug_long_event(debug_info_t *id, int level,
+					      unsigned long tag)
 {
-        unsigned long t=tag;
+	unsigned long t = tag;
+
 	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
 		return NULL;
-        return debug_event_common(id,level,&t,sizeof(unsigned long));
+	return debug_event_common(id, level, &t, sizeof(unsigned long));
 }
 
-static inline debug_entry_t*
-debug_text_event(debug_info_t* id, int level, const char* txt)
+/**
+ * debug_text_event() - writes string debug entry in ascii format to active
+ *			debug area (if level <= actual debug level)
+ *
+ * @id:		handle for debug log
+ * @level:	debug level
+ * @txt:	string for debug entry
+ *
+ * Return:
+ * - Address of written debug entry
+ * - %NULL if error
+ */
+static inline debug_entry_t *debug_text_event(debug_info_t *id, int level,
+					      const char *txt)
 {
 	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
 		return NULL;
-        return debug_event_common(id,level,txt,strlen(txt));
+	return debug_event_common(id, level, txt, strlen(txt));
 }
 
 /*
  * IMPORTANT: Use "%s" in sprintf format strings with care! Only pointers are
- * stored in the s390dbf. See Documentation/s390/s390dbf.txt for more details!
+ * stored in the s390dbf. See Documentation/arch/s390/s390dbf.rst for more details!
  */
 extern debug_entry_t *
-debug_sprintf_event(debug_info_t* id,int level,char *string,...)
+__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
 	__attribute__ ((format(printf, 3, 4)));
 
-
-static inline debug_entry_t*
-debug_exception(debug_info_t* id, int level, void* data, int length)
+/**
+ * debug_sprintf_event() - writes debug entry with format string
+ *			   and varargs (longs) to active debug area
+ *			   (if level $<=$ actual debug level).
+ *
+ * @_id:	handle for debug log
+ * @_level:	debug level
+ * @_fmt:	format string for debug entry
+ * @...:	varargs used as in sprintf()
+ *
+ * Return:
+ * - Address of written debug entry
+ * - %NULL if error
+ *
+ * floats and long long datatypes cannot be used as varargs.
+ */
+#define debug_sprintf_event(_id, _level, _fmt, ...)			\
+({									\
+	debug_entry_t *__ret;						\
+	debug_info_t *__id = _id;					\
+	int __level = _level;						\
+									\
+	if ((!__id) || (__level > __id->level))				\
+		__ret = NULL;						\
+	else								\
+		__ret = __debug_sprintf_event(__id, __level,		\
+					      _fmt, ## __VA_ARGS__);	\
+	__ret;								\
+})
+
+/**
+ * debug_exception() - writes binary debug entry to active debug area
+ *		       (if level <= actual debug level)
+ *		       and switches to next debug area
+ *
+ * @id:		handle for debug log
+ * @level:	debug level
+ * @data:	pointer to data for debug entry
+ * @length:	length of data in bytes
+ *
+ * Return:
+ * - Address of written debug entry
+ * - %NULL if error
+ */
+static inline debug_entry_t *debug_exception(debug_info_t *id, int level,
+					     void *data, int length)
 {
 	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
 		return NULL;
-        return debug_exception_common(id,level,data,length);
+	return debug_exception_common(id, level, data, length);
 }
 
-static inline debug_entry_t*
-debug_int_exception(debug_info_t* id, int level, unsigned int tag)
+/**
+ * debug_int_exception() - writes unsigned int debug entry to active debug area
+ *			   (if level <= actual debug level)
+ *			   and switches to next debug area
+ *
+ * @id:		handle for debug log
+ * @level:	debug level
+ * @tag:	integer value for debug entry
+ *
+ * Return:
+ * - Address of written debug entry
+ * - %NULL if error
+ */
+static inline debug_entry_t *debug_int_exception(debug_info_t *id, int level,
+						 unsigned int tag)
 {
-        unsigned int t=tag;
+	unsigned int t = tag;
+
 	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
 		return NULL;
-        return debug_exception_common(id,level,&t,sizeof(unsigned int));
+	return debug_exception_common(id, level, &t, sizeof(unsigned int));
 }
 
-static inline debug_entry_t *
-debug_long_exception (debug_info_t* id, int level, unsigned long tag)
+/**
+ * debug_long_exception() - writes long debug entry to active debug area
+ *			   (if level <= actual debug level)
+ *			   and switches to next debug area
+ *
+ * @id:		handle for debug log
+ * @level:	debug level
+ * @tag:	long integer value for debug entry
+ *
+ * Return:
+ * - Address of written debug entry
+ * - %NULL if error
+ */
+static inline debug_entry_t *debug_long_exception (debug_info_t *id, int level,
+						   unsigned long tag)
 {
-        unsigned long t=tag;
+	unsigned long t = tag;
+
 	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
 		return NULL;
-        return debug_exception_common(id,level,&t,sizeof(unsigned long));
+	return debug_exception_common(id, level, &t, sizeof(unsigned long));
 }
 
-static inline debug_entry_t*
-debug_text_exception(debug_info_t* id, int level, const char* txt)
+/**
+ * debug_text_exception() - writes string debug entry in ascii format to active
+ *			    debug area (if level <= actual debug level)
+ *			    and switches to next debug area
+ * area
+ *
+ * @id:	handle for debug log
+ * @level:	debug level
+ * @txt:	string for debug entry
+ *
+ * Return:
+ * - Address of written debug entry
+ * - %NULL if error
+ */
+static inline debug_entry_t *debug_text_exception(debug_info_t *id, int level,
+						  const char *txt)
 {
 	if ((!id) || (level > id->level) || (id->pages_per_area == 0))
 		return NULL;
-        return debug_exception_common(id,level,txt,strlen(txt));
+	return debug_exception_common(id, level, txt, strlen(txt));
 }
 
 /*
  * IMPORTANT: Use "%s" in sprintf format strings with care! Only pointers are
- * stored in the s390dbf. See Documentation/s390/s390dbf.txt for more details!
+ * stored in the s390dbf. See Documentation/arch/s390/s390dbf.rst for more details!
  */
 extern debug_entry_t *
-debug_sprintf_exception(debug_info_t* id,int level,char *string,...)
+__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
 	__attribute__ ((format(printf, 3, 4)));
 
-int debug_register_view(debug_info_t* id, struct debug_view* view);
-int debug_unregister_view(debug_info_t* id, struct debug_view* view);
+
+/**
+ * debug_sprintf_exception() - writes debug entry with format string and
+ *			       varargs (longs) to active debug area
+ *			       (if level <= actual debug level)
+ *			       and switches to next debug area.
+ *
+ * @_id:	handle for debug log
+ * @_level:	debug level
+ * @_fmt:	format string for debug entry
+ * @...:	varargs used as in sprintf()
+ *
+ * Return:
+ * - Address of written debug entry
+ * - %NULL if error
+ *
+ * floats and long long datatypes cannot be used as varargs.
+ */
+#define debug_sprintf_exception(_id, _level, _fmt, ...)			\
+({									\
+	debug_entry_t *__ret;						\
+	debug_info_t *__id = _id;					\
+	int __level = _level;						\
+									\
+	if ((!__id) || (__level > __id->level))				\
+		__ret = NULL;						\
+	else								\
+		__ret = __debug_sprintf_exception(__id, __level,	\
+						  _fmt, ## __VA_ARGS__);\
+	__ret;								\
+})
+
+int debug_register_view(debug_info_t *id, struct debug_view *view);
+
+int debug_unregister_view(debug_info_t *id, struct debug_view *view);
+
+#ifndef MODULE
+
+/*
+ * Note: Initial page and area numbers must be fixed to allow static
+ * initialization. This enables very early tracing. Changes to these values
+ * must be reflected in __DEFINE_STATIC_AREA.
+ */
+#define EARLY_PAGES		8
+#define EARLY_AREAS		1
+
+#define VNAME(var, suffix)	__##var##_##suffix
 
 /*
-   define the debug levels:
-   - 0 No debugging output to console or syslog
-   - 1 Log internal errors to syslog, ignore check conditions 
-   - 2 Log internal errors and check conditions to syslog
-   - 3 Log internal errors to console, log check conditions to syslog
-   - 4 Log internal errors and check conditions to console
-   - 5 panic on internal errors, log check conditions to console
-   - 6 panic on both, internal errors and check conditions
- */
-
-#ifndef DEBUG_LEVEL
-#define DEBUG_LEVEL 4
-#endif
-
-#define INTERNAL_ERRMSG(x,y...) "E" __FILE__ "%d: " x, __LINE__, y
-#define INTERNAL_WRNMSG(x,y...) "W" __FILE__ "%d: " x, __LINE__, y
-#define INTERNAL_INFMSG(x,y...) "I" __FILE__ "%d: " x, __LINE__, y
-#define INTERNAL_DEBMSG(x,y...) "D" __FILE__ "%d: " x, __LINE__, y
-
-#if DEBUG_LEVEL > 0
-#define PRINT_DEBUG(x...) printk ( KERN_DEBUG PRINTK_HEADER x )
-#define PRINT_INFO(x...) printk ( KERN_INFO PRINTK_HEADER x )
-#define PRINT_WARN(x...) printk ( KERN_WARNING PRINTK_HEADER x )
-#define PRINT_ERR(x...) printk ( KERN_ERR PRINTK_HEADER x )
-#define PRINT_FATAL(x...) panic ( PRINTK_HEADER x )
-#else
-#define PRINT_DEBUG(x...) printk ( KERN_DEBUG PRINTK_HEADER x )
-#define PRINT_INFO(x...) printk ( KERN_DEBUG PRINTK_HEADER x )
-#define PRINT_WARN(x...) printk ( KERN_DEBUG PRINTK_HEADER x )
-#define PRINT_ERR(x...) printk ( KERN_DEBUG PRINTK_HEADER x )
-#define PRINT_FATAL(x...) printk ( KERN_DEBUG PRINTK_HEADER x )
-#endif				/* DASD_DEBUG */
-
-#endif				/* DEBUG_H */
+ * Define static areas for early trace data. During boot debug_register_static()
+ * will replace these with dynamically allocated areas to allow custom page and
+ * area sizes, and dynamic resizing.
+ */
+#define __DEFINE_STATIC_AREA(var)					\
+static char VNAME(var, data)[EARLY_PAGES][PAGE_SIZE] __initdata;	\
+static debug_entry_t *VNAME(var, pages)[EARLY_PAGES] __initdata = {	\
+	(debug_entry_t *)VNAME(var, data)[0],				\
+	(debug_entry_t *)VNAME(var, data)[1],				\
+	(debug_entry_t *)VNAME(var, data)[2],				\
+	(debug_entry_t *)VNAME(var, data)[3],				\
+	(debug_entry_t *)VNAME(var, data)[4],				\
+	(debug_entry_t *)VNAME(var, data)[5],				\
+	(debug_entry_t *)VNAME(var, data)[6],				\
+	(debug_entry_t *)VNAME(var, data)[7],				\
+};									\
+static debug_entry_t **VNAME(var, areas)[EARLY_AREAS] __initdata = {	\
+	(debug_entry_t **)VNAME(var, pages),				\
+};									\
+static int VNAME(var, active_pages)[EARLY_AREAS] __initdata;		\
+static int VNAME(var, active_entries)[EARLY_AREAS] __initdata
+
+#define __DEBUG_INFO_INIT(var, _name, _buf_size) {			\
+	.next = NULL,							\
+	.prev = NULL,							\
+	.ref_count = REFCOUNT_INIT(1),					\
+	.lock = __SPIN_LOCK_UNLOCKED(var.lock),				\
+	.level = DEBUG_DEFAULT_LEVEL,					\
+	.nr_areas = EARLY_AREAS,					\
+	.pages_per_area = EARLY_PAGES,					\
+	.buf_size = (_buf_size),					\
+	.entry_size = sizeof(debug_entry_t) + (_buf_size),		\
+	.areas = VNAME(var, areas),					\
+	.active_area = 0,						\
+	.active_pages = VNAME(var, active_pages),			\
+	.active_entries = VNAME(var, active_entries),			\
+	.debugfs_root_entry = NULL,					\
+	.debugfs_entries = { NULL },					\
+	.views = { NULL },						\
+	.name = (_name),						\
+	.mode = 0600,							\
+}
+
+#define __REGISTER_STATIC_DEBUG_INFO(var, name, pages, areas, view)	\
+static int __init VNAME(var, reg)(void)					\
+{									\
+	debug_register_static(&var, (pages), (areas));			\
+	debug_register_view(&var, (view));				\
+	return 0;							\
+}									\
+arch_initcall(VNAME(var, reg))
+
+/**
+ * DEFINE_STATIC_DEBUG_INFO - Define static debug_info_t
+ *
+ * @var: Name of debug_info_t variable
+ * @name: Name of debug log (e.g. used for debugfs entry)
+ * @pages: Number of pages per area
+ * @nr_areas: Number of debug areas
+ * @buf_size: Size of data area in each debug entry
+ * @view: Pointer to debug view struct
+ *
+ * Define a static debug_info_t for early tracing. The associated debugfs log
+ * is automatically registered with the specified debug view.
+ *
+ * Important: Users of this macro must not call any of the
+ * debug_register/_unregister() functions for this debug_info_t!
+ *
+ * Note: Tracing will start with a fixed number of initial pages and areas.
+ * The debug area will be changed to use the specified numbers during
+ * arch_initcall.
+ */
+#define DEFINE_STATIC_DEBUG_INFO(var, name, pages, nr_areas, buf_size, view) \
+__DEFINE_STATIC_AREA(var);						\
+static debug_info_t __refdata var =					\
+	__DEBUG_INFO_INIT(var, (name), (buf_size));			\
+__REGISTER_STATIC_DEBUG_INFO(var, name, pages, nr_areas, view)
+
+void debug_register_static(debug_info_t *id, int pages_per_area, int nr_areas);
+
+#endif /* MODULE */
+
+#endif /* _ASM_S390_DEBUG_H */