From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Wed, 28 Jul 2021 20:19:56 +0000 (-0400)
Subject: Truncate aggregation sum to fit map bitness
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=4f8afc535e77070f1ef00434674f0417c6f9ef69;p=lttng-ust.git

Truncate aggregation sum to fit map bitness

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I89a77d9df897f2b1cc7bfc62dcc9e12f31e4a12b
---

diff --git a/src/common/counter/counter.c b/src/common/counter/counter.c
index 99a46af6..4f2ac4c8 100644
--- a/src/common/counter/counter.c
+++ b/src/common/counter/counter.c
@@ -453,6 +453,35 @@ int lttng_counter_aggregate(const struct lib_counter_config *config,
 	default:
 		return -EINVAL;
 	}
+	switch (config->counter_size) {
+	case COUNTER_SIZE_8_BIT:
+		if (sum > INT8_MAX)
+			*overflow = true;
+		if (sum < INT8_MIN)
+			*underflow = true;
+		sum = (int8_t) sum;	/* Truncate sum. */
+		break;
+	case COUNTER_SIZE_16_BIT:
+		if (sum > INT16_MAX)
+			*overflow = true;
+		if (sum < INT16_MIN)
+			*underflow = true;
+		sum = (int16_t) sum;	/* Truncate sum. */
+		break;
+	case COUNTER_SIZE_32_BIT:
+		if (sum > INT32_MAX)
+			*overflow = true;
+		if (sum < INT32_MIN)
+			*underflow = true;
+		sum = (int32_t) sum;	/* Truncate sum. */
+		break;
+#if CAA_BITS_PER_LONG == 64
+	case COUNTER_SIZE_64_BIT:
+		break;
+#endif
+	default:
+		return -EINVAL;
+	}
 	*value = sum;
 	return 0;
 }