[Xen-changelog] [xen master] spinlock: ensure the flags parameter is wide enough

[patchbot@xxxxxxx]

commit 170fa9967176c8627fe2e75dbe1dc5212019afde
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Tue Oct 22 17:16:29 2013 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Oct 22 17:16:29 2013 +0200

    spinlock: ensure the flags parameter is wide enough
    
    Because of the construction of spin_lock_irq() (and varients), the flags
    parameter could be trucated.  Use a BUILD_BUG_ON() to verify the width of 
the
    parameter.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Acked-by: Keir Fraser <keir@xxxxxxx>
    Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
 xen/include/xen/spinlock.h |   18 +++++++++++++++---
 1 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/xen/include/xen/spinlock.h b/xen/include/xen/spinlock.h
index 76581c5..12b0a89 100644
--- a/xen/include/xen/spinlock.h
+++ b/xen/include/xen/spinlock.h
@@ -188,7 +188,11 @@ int _rw_is_write_locked(rwlock_t *lock);
 
 #define spin_lock(l)                  _spin_lock(l)
 #define spin_lock_irq(l)              _spin_lock_irq(l)
-#define spin_lock_irqsave(l, f)       ((f) = _spin_lock_irqsave(l))
+#define spin_lock_irqsave(l, f)                                 \
+    ({                                                          \
+        BUILD_BUG_ON(sizeof(f) != sizeof(unsigned long));       \
+        ((f) = _spin_lock_irqsave(l));                          \
+    })
 
 #define spin_unlock(l)                _spin_unlock(l)
 #define spin_unlock_irq(l)            _spin_unlock_irq(l)
@@ -220,7 +224,11 @@ int _rw_is_write_locked(rwlock_t *lock);
 
 #define read_lock(l)                  _read_lock(l)
 #define read_lock_irq(l)              _read_lock_irq(l)
-#define read_lock_irqsave(l, f)       ((f) = _read_lock_irqsave(l))
+#define read_lock_irqsave(l, f)                                 \
+    ({                                                          \
+        BUILD_BUG_ON(sizeof(f) != sizeof(unsigned long));       \
+        ((f) = _read_lock_irqsave(l));                          \
+    })
 
 #define read_unlock(l)                _read_unlock(l)
 #define read_unlock_irq(l)            _read_unlock_irq(l)
@@ -229,7 +237,11 @@ int _rw_is_write_locked(rwlock_t *lock);
 
 #define write_lock(l)                 _write_lock(l)
 #define write_lock_irq(l)             _write_lock_irq(l)
-#define write_lock_irqsave(l, f)      ((f) = _write_lock_irqsave(l))
+#define write_lock_irqsave(l, f)                                \
+    ({                                                          \
+        BUILD_BUG_ON(sizeof(f) != sizeof(unsigned long));       \
+        ((f) = _write_lock_irqsave(l));                         \
+    })
 #define write_trylock(l)              _write_trylock(l)
 
 #define write_unlock(l)               _write_unlock(l)
--
generated by git-patchbot for /home/xen/git/xen.git#master

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