From ac6c4682f3df6e5069f5c0aed02a7e60eea834f8 Mon Sep 17 00:00:00 2001
From: Christian Prochaska <christian.prochaska@genode-labs.com>
Date: Tue, 18 Nov 2014 14:51:54 +0100
Subject: [PATCH] okl4: declare read-write-lock as volatile

GCC 4.7.4 and newer seems to optimize the lock-variable accesses more
radically, which uncovered the missing volatile qualifier and resulted
in:

Assertion "(int)locked >= 0" failed in file '.../okl4_x86/kernel/include/kernel/read_write_lock.h', line 151 (fn=f0104771)
--- "KD# assert" ---
---
 .../patches/read_write_lock_volatile.patch          | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 repos/base-okl4/patches/read_write_lock_volatile.patch

diff --git a/repos/base-okl4/patches/read_write_lock_volatile.patch b/repos/base-okl4/patches/read_write_lock_volatile.patch
new file mode 100644
index 000000000..c4dde6180
--- /dev/null
+++ b/repos/base-okl4/patches/read_write_lock_volatile.patch
@@ -0,0 +1,13 @@
+diff --git a/pistachio/include/read_write_lock.h b/pistachio/include/read_write_lock.h
+index d667451..49f7f30 100644
+--- a/pistachio/include/read_write_lock.h
++++ b/pistachio/include/read_write_lock.h
+@@ -123,7 +123,7 @@ struct read_write_lock_t
+     bool is_locked(void);
+ 
+ #if defined(CONFIG_DEBUG)
+-    word_t locked;
++    word_t volatile locked;
+ #endif
+ };
+