From: fincs <fincs.alt1@gmail.com>
Date: Wed, 7 Oct 2015 19:48:26 +0000 (+0200)
Subject: Fix potential race condition in LightLock_Unlock() (spotted by mtheall)
X-Git-Tag: v1.0.0~81
X-Git-Url: https://chaos.moe/g/?a=commitdiff_plain;h=141703b4eee4a7f8eb4b09d366d31af64181a907;p=corbenik%2Fctrulib.git

Fix potential race condition in LightLock_Unlock() (spotted by mtheall)
---

diff --git a/libctru/source/synchronization.c b/libctru/source/synchronization.c
index 146a539..9bc293f 100644
--- a/libctru/source/synchronization.c
+++ b/libctru/source/synchronization.c
@@ -50,7 +50,7 @@ void LightLock_Unlock(LightLock* lock)
 		// Wake up exactly one thread
 		do
 			val = __ldrex(lock);
-		while (__strex(lock, val-1));
+		while (__strex(lock, val >= 0 ? (val-1) : (val+1)));
 		svcArbitrateAddress(arbiter, (u32)lock, ARBITRATION_SIGNAL, 1, 0);
 	}
 }