[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>

diff --git a/arch/s390/kernel/debug.c b/arch/s390/kernel/debug.c
index 960ba60..bc59282 100644 (file)
--- a/arch/s390/kernel/debug.c
+++ b/arch/s390/kernel/debug.c
@@ -62,7 +62,7 @@ typedef struct
 } 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 @@ debug_info_copy(debug_info_t* in, int mode)
 {
         int i,j;
         debug_info_t* rc;
+        unsigned long flags;
+
+       /* 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);
 
-        rc = debug_info_alloc(in->name, in->pages_per_area, in->nr_areas,
-                               in->buf_size, in->level, mode);
         if(!rc || (mode == NO_AREAS))
                 goto out;
 
@@ -386,6 +401,7 @@ debug_info_copy(debug_info_t* in, int mode)
                }
         }
 out:
+        spin_unlock_irqrestore(&in->lock, flags);
         return rc;
 }
 
@@ -593,19 +609,15 @@ debug_open(struct inode *inode, struct file *file)
        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 @@ extern inline void
 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 @@ debug_register_view(debug_info_t * id, struct debug_view *view)
        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 @@ int
 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 @@ debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
        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 @@ debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
                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;
 }

diff --git a/include/asm-s390/debug.h b/include/asm-s390/debug.h
index 92360d9..7127030 100644 (file)
--- a/include/asm-s390/debug.h
+++ b/include/asm-s390/debug.h
@@ -52,8 +52,6 @@ struct __debug_entry{
 #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;