x86, perf_counter, bts: Correct pointer-to-u64 casts

On 32bit, pointers in the DS AREA configuration are cast to
u64. The current (long) cast to avoid compiler warnings results
in a signed 64bit address.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090902140615.305889000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/cpu/perf_counter.c

@@ -726,7 +726,8 @@ static inline void init_debug_store_on_cpu(int cpu)
 		return;
 
 	wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA,
-		     (u32)((u64)(long)ds), (u32)((u64)(long)ds >> 32));
+		     (u32)((u64)(unsigned long)ds),
+		     (u32)((u64)(unsigned long)ds >> 32));
 }
 
 static inline void fini_debug_store_on_cpu(int cpu)
@@ -757,7 +758,7 @@ static void release_bts_hardware(void)
 
 		per_cpu(cpu_hw_counters, cpu).ds = NULL;
 
-		kfree((void *)(long)ds->bts_buffer_base);
+		kfree((void *)(unsigned long)ds->bts_buffer_base);
 		kfree(ds);
 	}
 
@@ -788,7 +789,7 @@ static int reserve_bts_hardware(void)
 			break;
 		}
 
-		ds->bts_buffer_base = (u64)(long)buffer;
+		ds->bts_buffer_base = (u64)(unsigned long)buffer;
 		ds->bts_index = ds->bts_buffer_base;
 		ds->bts_absolute_maximum =
 			ds->bts_buffer_base + BTS_BUFFER_SIZE;
@@ -1491,27 +1492,26 @@ static void intel_pmu_drain_bts_buffer(struct cpu_hw_counters *cpuc,
 	};
 	struct perf_counter *counter = cpuc->counters[X86_PMC_IDX_FIXED_BTS];
 	unsigned long orig_ip = data->regs->ip;
-	u64 at;
+	struct bts_record *at, *top;
 
 	if (!counter)
 		return;
 
 	if (!ds)
 		return;
 
-	for (at = ds->bts_buffer_base;
-	     at < ds->bts_index;
-	     at += sizeof(struct bts_record)) {
-		struct bts_record *rec = (struct bts_record *)(long)at;
+	at  = (struct bts_record *)(unsigned long)ds->bts_buffer_base;
+	top = (struct bts_record *)(unsigned long)ds->bts_index;
 
-		data->regs->ip	= rec->from;
-		data->addr	= rec->to;
+	ds->bts_index = ds->bts_buffer_base;
+
+	for (; at < top; at++) {
+		data->regs->ip	= at->from;
+		data->addr	= at->to;
 
 		perf_counter_output(counter, 1, data);
 	}
 
-	ds->bts_index = ds->bts_buffer_base;
-
 	data->regs->ip	= orig_ip;
 	data->addr	= 0;