[patch 2/10] s390: debug feature changes.

From: Martin Schwidefsky
Date: Mon Aug 29 2005 - 12:54:32 EST


[patch 2/10] s390: debug feature changes.

From: Michael Holzheu <holzheu@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>

diffstat:
arch/s390/kernel/debug.c | 52 ++++++++++++++++++++++++++++-------------------
include/asm-s390/debug.h | 2 -
2 files changed, 32 insertions(+), 22 deletions(-)

diff -urpN linux-2.6/arch/s390/kernel/debug.c linux-2.6-patched/arch/s390/kernel/debug.c
--- linux-2.6/arch/s390/kernel/debug.c 2005-08-29 01:41:01.000000000 +0200
+++ linux-2.6-patched/arch/s390/kernel/debug.c 2005-08-29 19:18:06.000000000 +0200
@@ -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 mo
{
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 mo
}
}
out:
+ spin_unlock_irqrestore(&in->lock, flags);
return rc;
}

@@ -593,19 +609,15 @@ debug_open(struct inode *inode, struct f
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, s
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,
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,
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 -urpN linux-2.6/include/asm-s390/debug.h linux-2.6-patched/include/asm-s390/debug.h
--- linux-2.6/include/asm-s390/debug.h 2005-08-29 01:41:01.000000000 +0200
+++ linux-2.6-patched/include/asm-s390/debug.h 2005-08-29 19:18:06.000000000 +0200
@@ -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;
-
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