From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Thu, 26 Nov 2020 20:29:28 +0000 (-0500)
Subject: Fix: counter: cast UINT*_MAX to 64-bit signed type before negative
X-Git-Tag: v2.13.0-rc1~79
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=f801323dd7650782241e276d5a2971fc37312fa8;p=lttng-modules.git

Fix: counter: cast UINT*_MAX to 64-bit signed type before negative

(long long)-UINT32_MAX leads to value 1 which is not what we expect.
This is due to implicit type promotion from unsigned to signed 32-bit
integer.

Apply this to 8-bit and 16-bit types as well even though they are
not affected by this issue to keep things regular.

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

diff --git a/include/counter/counter-api.h b/include/counter/counter-api.h
index 827fb6f8..02d709a1 100644
--- a/include/counter/counter-api.h
+++ b/include/counter/counter-api.h
@@ -83,7 +83,7 @@ static inline int __lttng_counter_add(const struct lib_counter_config *config,
 		}
 		if (v > 0 && (v >= U8_MAX || n < old))
 			overflow = true;
-		else if (v < 0 && (v <= -U8_MAX || n > old))
+		else if (v < 0 && (v <= -(s64) U8_MAX || n > old))
 			underflow = true;
 		break;
 	}
@@ -122,7 +122,7 @@ static inline int __lttng_counter_add(const struct lib_counter_config *config,
 		}
 		if (v > 0 && (v >= U16_MAX || n < old))
 			overflow = true;
-		else if (v < 0 && (v <= -U16_MAX || n > old))
+		else if (v < 0 && (v <= -(s64) U16_MAX || n > old))
 			underflow = true;
 		break;
 	}
@@ -161,7 +161,7 @@ static inline int __lttng_counter_add(const struct lib_counter_config *config,
 		}
 		if (v > 0 && (v >= U32_MAX || n < old))
 			overflow = true;
-		else if (v < 0 && (v <= -U32_MAX || n > old))
+		else if (v < 0 && (v <= -(s64) U32_MAX || n > old))
 			underflow = true;
 		break;
 	}