[S390] Add debug_register_mode() function to debug feature API

The new function supports setting of permissions for the debugfs files created by the debug feature. In addition to that, the function provides uid and gid as parameters for future use. Currently only root is allowed for uid and gid. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

[S390] Add debug_register_mode() function to debug feature API
The new function supports setting of permissions for the debugfs files created by the debug feature. In addition to that, the function provides uid and gid as parameters for future use. Currently only root is allowed for uid and gid. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Michael Holzheu · Heiko Carstens
1 parent 9f7819c1e5
Showing 3 changed files with 64 additions and 13 deletions Side-by-side Diff
Documentation/s390/s390dbf.txt
arch/s390/kernel/debug.c
include/asm-s390/debug.h
@@ -115,6 +115,27 @@
 Description:  Allocates memory for a debug log     
               Must not be called within an interrupt handler 
  
+----------------------------------------------------------------------------
+debug_info_t *debug_register_mode(char *name, int pages, int nr_areas,
+				  int buf_size, mode_t mode, uid_t uid,
+				  gid_t gid);
+
+Parameter:    name:	   Name of debug log (e.g. used for debugfs entry)
+	      pages:	   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 Value: Handle for generated debug area
+	      NULL if register failed
+
+Description:  Allocates memory for a debug log
+	      Must not be called within an interrupt handler
+
 ---------------------------------------------------------------------------
 void debug_unregister (debug_info_t * id);
  
@@ -73,7 +73,7 @@
 static int debug_open(struct inode *inode, struct file *file);
 static int debug_close(struct inode *inode, struct file *file);
 static debug_info_t*  debug_info_create(char *name, int pages_per_area,
-			int nr_areas, int buf_size);
+			int nr_areas, int buf_size, mode_t mode);
 static void debug_info_get(debug_info_t *);
 static void debug_info_put(debug_info_t *);
 static int debug_prolog_level_fn(debug_info_t * id,
@@ -327,7 +327,8 @@
  */
  
 static debug_info_t*
-debug_info_create(char *name, int pages_per_area, int nr_areas, int buf_size)
+debug_info_create(char *name, int pages_per_area, int nr_areas, int buf_size,
+		  mode_t mode)
 {
 	debug_info_t* rc;
  
@@ -336,6 +337,8 @@
         if(!rc) 
 		goto out;
  
+	rc->mode = mode & ~S_IFMT;
+
 	/* create root directory */
         rc->debugfs_root_entry = debugfs_create_dir(rc->name,
 					debug_debugfs_root_entry);
  
  
  
@@ -676,23 +679,30 @@
 }
  
 /*
- * debug_register:
- * - creates and initializes debug area for the caller
- * - returns handle for debug area
+ * 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_info_t*
-debug_register (char *name, int pages_per_area, int nr_areas, int buf_size)
+debug_info_t *debug_register_mode(char *name, int pages_per_area, int nr_areas,
+				  int buf_size, mode_t mode, uid_t uid,
+				  gid_t gid)
 {
 	debug_info_t *rc = NULL;
  
+	/* Since debugfs currently does not support uid/gid other than root, */
+	/* we do not allow gid/uid != 0 until we get support for that. */
+	if ((uid != 0) || (gid != 0))
+		printk(KERN_WARNING "debug: Warning - Currently only uid/gid "
+		       "= 0 are supported. Using root as owner now!");
 	if (!initialized)
 		BUG();
 	mutex_lock(&debug_mutex);
  
         /* create new debug_info */
  
-	rc = debug_info_create(name, pages_per_area, nr_areas, buf_size);
+	rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
 	if(!rc) 
 		goto out;
 	debug_register_view(rc, &debug_level_view);
  
@@ -705,8 +715,22 @@
 	mutex_unlock(&debug_mutex);
 	return rc;
 }
+EXPORT_SYMBOL(debug_register_mode);
  
 /*
+ * debug_register:
+ * - creates and initializes debug area for the caller
+ * - returns handle for debug area
+ */
+
+debug_info_t *debug_register(char *name, int pages_per_area, int nr_areas,
+			     int buf_size)
+{
+	return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
+				   S_IRUSR | S_IWUSR, 0, 0);
+}
+
+/*
  * debug_unregister:
  * - give back debug area
  */
  
@@ -1073,15 +1097,16 @@
 	int rc = 0;
 	int i;
 	unsigned long flags;
-	mode_t mode = S_IFREG;
+	mode_t mode;
 	struct dentry *pde;
  
 	if (!id)
 		goto out;
-	if (view->prolog_proc || view->format_proc || view->header_proc)
-		mode |= S_IRUSR;
-	if (view->input_proc)
-		mode |= S_IWUSR;
+	mode = (id->mode | S_IFREG) & ~S_IXUGO;
+	if (!(view->prolog_proc || view->format_proc || view->header_proc))
+		mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
+	if (!view->input_proc)
+		mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
 	pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
 				id , &debug_file_ops);
 	if (!pde){
@@ -73,6 +73,7 @@
 	struct dentry* debugfs_entries[DEBUG_MAX_VIEWS];
 	struct debug_view* views[DEBUG_MAX_VIEWS];	
 	char name[DEBUG_MAX_NAME_LEN];
+	mode_t mode;
 } debug_info_t;
  
 typedef int (debug_header_proc_t) (debug_info_t* id,
@@ -121,6 +122,10 @@
  
 debug_info_t* debug_register(char* name, int pages, int nr_areas,
                              int buf_size);
+
+debug_info_t *debug_register_mode(char *name, int pages, int nr_areas,
+				  int buf_size, mode_t mode, uid_t uid,
+				  gid_t gid);
  
 void debug_unregister(debug_info_t* id);
...	...	@@ -115,6 +115,27 @@
115	115	Description: Allocates memory for a debug log
116	116	Must not be called within an interrupt handler
117	117
	118	+----------------------------------------------------------------------------
	119	+debug_info_t debug_register_mode(char name, int pages, int nr_areas,
	120	+ int buf_size, mode_t mode, uid_t uid,
	121	+ gid_t gid);
	122	+
	123	+Parameter: name: Name of debug log (e.g. used for debugfs entry)
	124	+ pages: Number of pages, which will be allocated per area
	125	+ nr_areas: Number of debug areas
	126	+ buf_size: Size of data area in each debug entry
	127	+ mode: File mode for debugfs files. E.g. S_IRWXUGO
	128	+ uid: User ID for debugfs files. Currently only 0 is
	129	+ supported.
	130	+ gid: Group ID for debugfs files. Currently only 0 is
	131	+ supported.
	132	+
	133	+Return Value: Handle for generated debug area
	134	+ NULL if register failed
	135	+
	136	+Description: Allocates memory for a debug log
	137	+ Must not be called within an interrupt handler
	138	+
118	139	---------------------------------------------------------------------------
119	140	void debug_unregister (debug_info_t * id);
120	141
...	...	@@ -73,7 +73,7 @@
73	73	static int debug_open(struct inode inode, struct file file);
74	74	static int debug_close(struct inode inode, struct file file);
75	75	static debug_info_t* debug_info_create(char *name, int pages_per_area,
76		- int nr_areas, int buf_size);
	76	+ int nr_areas, int buf_size, mode_t mode);
77	77	static void debug_info_get(debug_info_t *);
78	78	static void debug_info_put(debug_info_t *);
79	79	static int debug_prolog_level_fn(debug_info_t * id,
...	...	@@ -327,7 +327,8 @@
327	327	*/
328	328
329	329	static debug_info_t*
330		-debug_info_create(char *name, int pages_per_area, int nr_areas, int buf_size)
	330	+debug_info_create(char *name, int pages_per_area, int nr_areas, int buf_size,
	331	+ mode_t mode)
331	332	{
332	333	debug_info_t* rc;
333	334
...	...	@@ -336,6 +337,8 @@
336	337	if(!rc)
337	338	goto out;
338	339
	340	+ rc->mode = mode & ~S_IFMT;
	341	+
339	342	/* create root directory */
340	343	rc->debugfs_root_entry = debugfs_create_dir(rc->name,
341	344	debug_debugfs_root_entry);
342	345
343	346
344	347
...	...	@@ -676,23 +679,30 @@
676	679	}
677	680
678	681	/*
679		- * debug_register:
680		- * - creates and initializes debug area for the caller
681		- * - returns handle for debug area
	682	+ * debug_register_mode:
	683	+ * - Creates and initializes debug area for the caller
	684	+ * The mode parameter allows to specify access rights for the s390dbf files
	685	+ * - Returns handle for debug area
682	686	*/
683	687
684		-debug_info_t*
685		-debug_register (char *name, int pages_per_area, int nr_areas, int buf_size)
	688	+debug_info_t debug_register_mode(char name, int pages_per_area, int nr_areas,
	689	+ int buf_size, mode_t mode, uid_t uid,
	690	+ gid_t gid)
686	691	{
687	692	debug_info_t *rc = NULL;
688	693
	694	+ /* Since debugfs currently does not support uid/gid other than root, */
	695	+ /* we do not allow gid/uid != 0 until we get support for that. */
	696	+ if ((uid != 0) \|\| (gid != 0))
	697	+ printk(KERN_WARNING "debug: Warning - Currently only uid/gid "
	698	+ "= 0 are supported. Using root as owner now!");
689	699	if (!initialized)
690	700	BUG();
691	701	mutex_lock(&debug_mutex);
692	702
693	703	/* create new debug_info */
694	704
695		- rc = debug_info_create(name, pages_per_area, nr_areas, buf_size);
	705	+ rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
696	706	if(!rc)
697	707	goto out;
698	708	debug_register_view(rc, &debug_level_view);
699	709
...	...	@@ -705,8 +715,22 @@
705	715	mutex_unlock(&debug_mutex);
706	716	return rc;
707	717	}
	718	+EXPORT_SYMBOL(debug_register_mode);
708	719
709	720	/*
	721	+ * debug_register:
	722	+ * - creates and initializes debug area for the caller
	723	+ * - returns handle for debug area
	724	+ */
	725	+
	726	+debug_info_t debug_register(char name, int pages_per_area, int nr_areas,
	727	+ int buf_size)
	728	+{
	729	+ return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
	730	+ S_IRUSR \| S_IWUSR, 0, 0);
	731	+}
	732	+
	733	+/*
710	734	* debug_unregister:
711	735	* - give back debug area
712	736	*/
713	737
...	...	@@ -1073,15 +1097,16 @@
1073	1097	int rc = 0;
1074	1098	int i;
1075	1099	unsigned long flags;
1076		- mode_t mode = S_IFREG;
	1100	+ mode_t mode;
1077	1101	struct dentry *pde;
1078	1102
1079	1103	if (!id)
1080	1104	goto out;
1081		- if (view->prolog_proc \|\| view->format_proc \|\| view->header_proc)
1082		- mode \|= S_IRUSR;
1083		- if (view->input_proc)
1084		- mode \|= S_IWUSR;
	1105	+ mode = (id->mode \| S_IFREG) & ~S_IXUGO;
	1106	+ if (!(view->prolog_proc \|\| view->format_proc \|\| view->header_proc))
	1107	+ mode &= ~(S_IRUSR \| S_IRGRP \| S_IROTH);
	1108	+ if (!view->input_proc)
	1109	+ mode &= ~(S_IWUSR \| S_IWGRP \| S_IWOTH);
1085	1110	pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1086	1111	id , &debug_file_ops);
1087	1112	if (!pde){
...	...	@@ -73,6 +73,7 @@
73	73	struct dentry* debugfs_entries[DEBUG_MAX_VIEWS];
74	74	struct debug_view* views[DEBUG_MAX_VIEWS];
75	75	char name[DEBUG_MAX_NAME_LEN];
	76	+ mode_t mode;
76	77	} debug_info_t;
77	78
78	79	typedef int (debug_header_proc_t) (debug_info_t* id,
...	...	@@ -121,6 +122,10 @@
121	122
122	123	debug_info_t* debug_register(char* name, int pages, int nr_areas,
123	124	int buf_size);
	125	+
	126	+debug_info_t debug_register_mode(char name, int pages, int nr_areas,
	127	+ int buf_size, mode_t mode, uid_t uid,
	128	+ gid_t gid);
124	129
125	130	void debug_unregister(debug_info_t* id);
126	131