x86, bts: turn BUG_ON into WARN_ON_ONCE

Impact: make the ds code more debuggable

Turn BUG_ON's into WARN_ON_ONCE.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/ds.c

@@ -452,7 +452,7 @@ struct pebs_tracer *ds_request_pebs(struct task_struct *task,
 
 static void ds_release(struct ds_tracer *tracer, enum ds_qualifier qual)
 {
-	BUG_ON(tracer->context->owner[qual] != tracer);
+	WARN_ON_ONCE(tracer->context->owner[qual] != tracer);
 	tracer->context->owner[qual] = NULL;
 
 	put_tracer(tracer->context->task);
@@ -774,7 +774,7 @@ ds_configure(const struct ds_configuration *cfg)
 
 	printk(KERN_INFO "DS available\n");
 
-	BUG_ON(MAX_SIZEOF_DS < ds_cfg.sizeof_ds);
+	WARN_ON_ONCE(MAX_SIZEOF_DS < ds_cfg.sizeof_ds);
 }
 
 void __cpuinit ds_init_intel(struct cpuinfo_x86 *c)

arch/x86/kernel/ptrace.c

@@ -878,7 +878,8 @@ static int ptrace_bts_write_record(struct task_struct *child,
 {
 	unsigned char bts_record[BTS_MAX_RECORD_SIZE];
 
-	BUG_ON(BTS_MAX_RECORD_SIZE < bts_cfg.sizeof_bts);
+	if (BTS_MAX_RECORD_SIZE < bts_cfg.sizeof_bts)
+		return -EOVERFLOW;
 
 	memset(bts_record, 0, bts_cfg.sizeof_bts);
 	switch (in->qualifier) {
@@ -1133,7 +1134,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 
 		ret = ds_get_bts_index(child->bts, &size);
 		if (ret == 0) {
-			BUG_ON(size != (int) size);
+			WARN_ON_ONCE(size != (int) size);
 			ret = (int) size;
 		}
 		break;