[PATCH] s390: debug feature changes

debug feature changes/bug fixes: - Use get_clock() function instead of private inline assembly. - Use 'struct timeval' instead of 'struct timespec' for call to tod_to_timeval(). Now the microsecond part of the timestamp is correct again. - Fix a locking problem: when creating a snapshot of the current content of the debug areas, lock the entire debug_info object. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] s390: debug feature changes
debug feature changes/bug fixes: - Use get_clock() function instead of private inline assembly. - Use 'struct timeval' instead of 'struct timespec' for call to tod_to_timeval(). Now the microsecond part of the timestamp is correct again. - Fix a locking problem: when creating a snapshot of the current content of the debug areas, lock the entire debug_info object. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Michael Holzheu · Linus Torvalds
1 parent ae6aa2ea89
Showing 2 changed files with 32 additions and 22 deletions Side-by-side Diff
arch/s390/kernel/debug.c
include/asm-s390/debug.h
@@ -62,7 +62,7 @@
 } debug_sprintf_entry_t;
  
  
-extern void tod_to_timeval(uint64_t todval, struct timeval *xtime);
+extern void tod_to_timeval(uint64_t todval, struct timespec *xtime);
  
 /* internal function prototyes */
  
  
@@ -374,9 +374,24 @@
 {
         int i,j;
         debug_info_t* rc;
+        unsigned long flags;
  
-        rc = debug_info_alloc(in->name, in->pages_per_area, in->nr_areas,
-				in->buf_size, in->level, mode);
+	/* get a consistent copy of the debug areas */
+	do {
+		rc = debug_info_alloc(in->name, in->pages_per_area,
+			in->nr_areas, in->buf_size, in->level, mode);
+		spin_lock_irqsave(&in->lock, flags);
+		if(!rc)
+			goto out;
+		/* has something changed in the meantime ? */
+		if((rc->pages_per_area == in->pages_per_area) &&
+		   (rc->nr_areas == in->nr_areas)) {
+			break;
+		}
+		spin_unlock_irqrestore(&in->lock, flags);
+		debug_info_free(rc);
+	} while (1);
+
         if(!rc || (mode == NO_AREAS))
                 goto out;
  
@@ -386,6 +401,7 @@
 		}
         }
 out:
+        spin_unlock_irqrestore(&in->lock, flags);
         return rc;
 }
  
  
@@ -593,19 +609,15 @@
 	debug_info_t *debug_info, *debug_info_snapshot;
  
 	down(&debug_lock);
-
-	/* find debug log and view */
-	debug_info = debug_area_first;
-	while(debug_info != NULL){
-		for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
-			if (!debug_info->views[i])
-				continue;
-			else if (debug_info->debugfs_entries[i] ==
-				 file->f_dentry) {
-				goto found;	/* found view ! */
-			}
+	debug_info = (struct debug_info*)file->f_dentry->d_inode->u.generic_ip;
+	/* find debug view */
+	for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
+		if (!debug_info->views[i])
+			continue;
+		else if (debug_info->debugfs_entries[i] ==
+			 file->f_dentry) {
+			goto found;	/* found view ! */
 		}
-		debug_info = debug_info->next;
 	}
 	/* no entry found */
 	rc = -EINVAL;
@@ -833,7 +845,7 @@
 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
 			int exception)
 {
-	STCK(active->id.stck);
+	active->id.stck = get_clock();
 	active->id.fields.cpuid = smp_processor_id();
 	active->caller = __builtin_return_address(0);
 	active->id.fields.exception = exception;
@@ -1078,7 +1090,7 @@
 	if (view->input_proc)
 		mode |= S_IWUSR;
 	pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
-				NULL, &debug_file_ops);
+				id , &debug_file_ops);
 	if (!pde){
 		printk(KERN_WARNING "debug: debugfs_create_file() failed!"\
 			" Cannot register view %s/%s\n", id->name,view->name);
@@ -1432,7 +1444,7 @@
 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
 			 int area, debug_entry_t * entry, char *out_buf)
 {
-	struct timeval time_val;
+	struct timespec time_spec;
 	unsigned long long time;
 	char *except_str;
 	unsigned long caller;
@@ -1443,7 +1455,7 @@
 	time = entry->id.stck;
 	/* adjust todclock to 1970 */
 	time -= 0x8126d60e46000000LL - (0x3c26700LL * 1000000 * 4096);
-	tod_to_timeval(time, &time_val);
+	tod_to_timeval(time, &time_spec);
  
 	if (entry->id.fields.exception)
 		except_str = "*";
@@ -1451,7 +1463,7 @@
 		except_str = "-";
 	caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
 	rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p  ",
-		      area, time_val.tv_sec, time_val.tv_usec, level,
+		      area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
 		      except_str, entry->id.fields.cpuid, (void *) caller);
 	return rc;
 }
@@ -52,8 +52,6 @@
 #define DEBUG_DATA(entry) (char*)(entry + 1) /* data is stored behind */
                                              /* the entry information */
  
-#define STCK(x)	asm volatile ("STCK 0(%1)" : "=m" (x) : "a" (&(x)) : "cc")
-
 typedef struct __debug_entry debug_entry_t;
  
 struct debug_view;
...	...	@@ -62,7 +62,7 @@
62	62	} debug_sprintf_entry_t;
63	63
64	64
65		-extern void tod_to_timeval(uint64_t todval, struct timeval *xtime);
	65	+extern void tod_to_timeval(uint64_t todval, struct timespec *xtime);
66	66
67	67	/* internal function prototyes */
68	68
69	69
...	...	@@ -374,9 +374,24 @@
374	374	{
375	375	int i,j;
376	376	debug_info_t* rc;
	377	+ unsigned long flags;
377	378
378		- rc = debug_info_alloc(in->name, in->pages_per_area, in->nr_areas,
379		- in->buf_size, in->level, mode);
	379	+ /* get a consistent copy of the debug areas */
	380	+ do {
	381	+ rc = debug_info_alloc(in->name, in->pages_per_area,
	382	+ in->nr_areas, in->buf_size, in->level, mode);
	383	+ spin_lock_irqsave(&in->lock, flags);
	384	+ if(!rc)
	385	+ goto out;
	386	+ /* has something changed in the meantime ? */
	387	+ if((rc->pages_per_area == in->pages_per_area) &&
	388	+ (rc->nr_areas == in->nr_areas)) {
	389	+ break;
	390	+ }
	391	+ spin_unlock_irqrestore(&in->lock, flags);
	392	+ debug_info_free(rc);
	393	+ } while (1);
	394	+
380	395	if(!rc \|\| (mode == NO_AREAS))
381	396	goto out;
382	397
...	...	@@ -386,6 +401,7 @@
386	401	}
387	402	}
388	403	out:
	404	+ spin_unlock_irqrestore(&in->lock, flags);
389	405	return rc;
390	406	}
391	407
392	408
...	...	@@ -593,19 +609,15 @@
593	609	debug_info_t debug_info, debug_info_snapshot;
594	610
595	611	down(&debug_lock);
596		-
597		- /* find debug log and view */
598		- debug_info = debug_area_first;
599		- while(debug_info != NULL){
600		- for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
601		- if (!debug_info->views[i])
602		- continue;
603		- else if (debug_info->debugfs_entries[i] ==
604		- file->f_dentry) {
605		- goto found; /* found view ! */
606		- }
	612	+ debug_info = (struct debug_info*)file->f_dentry->d_inode->u.generic_ip;
	613	+ /* find debug view */
	614	+ for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
	615	+ if (!debug_info->views[i])
	616	+ continue;
	617	+ else if (debug_info->debugfs_entries[i] ==
	618	+ file->f_dentry) {
	619	+ goto found; /* found view ! */
607	620	}
608		- debug_info = debug_info->next;
609	621	}
610	622	/* no entry found */
611	623	rc = -EINVAL;
...	...	@@ -833,7 +845,7 @@
833	845	debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
834	846	int exception)
835	847	{
836		- STCK(active->id.stck);
	848	+ active->id.stck = get_clock();
837	849	active->id.fields.cpuid = smp_processor_id();
838	850	active->caller = __builtin_return_address(0);
839	851	active->id.fields.exception = exception;
...	...	@@ -1078,7 +1090,7 @@
1078	1090	if (view->input_proc)
1079	1091	mode \|= S_IWUSR;
1080	1092	pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1081		- NULL, &debug_file_ops);
	1093	+ id , &debug_file_ops);
1082	1094	if (!pde){
1083	1095	printk(KERN_WARNING "debug: debugfs_create_file() failed!"\
1084	1096	" Cannot register view %s/%s\n", id->name,view->name);
...	...	@@ -1432,7 +1444,7 @@
1432	1444	debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1433	1445	int area, debug_entry_t * entry, char *out_buf)
1434	1446	{
1435		- struct timeval time_val;
	1447	+ struct timespec time_spec;
1436	1448	unsigned long long time;
1437	1449	char *except_str;
1438	1450	unsigned long caller;
...	...	@@ -1443,7 +1455,7 @@
1443	1455	time = entry->id.stck;
1444	1456	/* adjust todclock to 1970 */
1445	1457	time -= 0x8126d60e46000000LL - (0x3c26700LL * 1000000 * 4096);
1446		- tod_to_timeval(time, &time_val);
	1458	+ tod_to_timeval(time, &time_spec);
1447	1459
1448	1460	if (entry->id.fields.exception)
1449	1461	except_str = "*";
...	...	@@ -1451,7 +1463,7 @@
1451	1463	except_str = "-";
1452	1464	caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1453	1465	rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ",
1454		- area, time_val.tv_sec, time_val.tv_usec, level,
	1466	+ area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1455	1467	except_str, entry->id.fields.cpuid, (void *) caller);
1456	1468	return rc;
1457	1469	}
...	...	@@ -52,8 +52,6 @@
52	52	#define DEBUG_DATA(entry) (char)(entry + 1) / data is stored behind */
53	53	/* the entry information */
54	54
55		-#define STCK(x) asm volatile ("STCK 0(%1)" : "=m" (x) : "a" (&(x)) : "cc")
56		-
57	55	typedef struct __debug_entry debug_entry_t;
58	56
59	57	struct debug_view;