locking: add typecheck on irqsave and friends for correct flags

There haave been several areas in the kernel where an int has been used for
flags in local_irq_save() and friends instead of a long.  This can cause some
hard to debug problems on some architectures.

This patch adds a typecheck inside the irqsave and restore functions to flag
these cases.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 56 insertions, 16 deletions

diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index d311a090fae7..61e5610ad165 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -46,6 +46,7 @@
  *  linux/spinlock.h:     builds the final spin_*() APIs.
  */
 
+#include <linux/typecheck.h>
 #include <linux/preempt.h>
 #include <linux/linkage.h>
 #include <linux/compiler.h>
@@ -191,23 +192,53 @@ do {								\
 
 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
 
-#define spin_lock_irqsave(lock, flags)  flags = _spin_lock_irqsave(lock)
-#define read_lock_irqsave(lock, flags)  flags = _read_lock_irqsave(lock)
-#define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock)
+#define spin_lock_irqsave(lock, flags)                  \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                flags = _spin_lock_irqsave(lock);       \
+        } while (0)
+#define read_lock_irqsave(lock, flags)                  \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                flags = _read_lock_irqsave(lock);       \
+        } while (0)
+#define write_lock_irqsave(lock, flags)                 \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                flags = _write_lock_irqsave(lock);      \
+        } while (0)
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
-#define spin_lock_irqsave_nested(lock, flags, subclass) \
-        flags = _spin_lock_irqsave_nested(lock, subclass)
+#define spin_lock_irqsave_nested(lock, flags, subclass)                 \
+        do {                                                            \
+                typecheck(unsigned long, flags);                        \
+                flags = _spin_lock_irqsave_nested(lock, subclass);      \
+        } while (0)
 #else
-#define spin_lock_irqsave_nested(lock, flags, subclass) \
-        flags = _spin_lock_irqsave(lock)
+#define spin_lock_irqsave_nested(lock, flags, subclass)                 \
+        do {                                                            \
+                typecheck(unsigned long, flags);                        \
+                flags = _spin_lock_irqsave(lock);                       \
+        } while (0)
 #endif
 
 #else
 
-#define spin_lock_irqsave(lock, flags)  _spin_lock_irqsave(lock, flags)
-#define read_lock_irqsave(lock, flags)  _read_lock_irqsave(lock, flags)
-#define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags)
+#define spin_lock_irqsave(lock, flags)                  \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                _spin_lock_irqsave(lock, flags);        \
+        } while (0)
+#define read_lock_irqsave(lock, flags)                  \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                _read_lock_irqsave(lock, flags);        \
+        } while (0)
+#define write_lock_irqsave(lock, flags)                 \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                _write_lock_irqsave(lock, flags);       \
+        } while (0)
 #define spin_lock_irqsave_nested(lock, flags, subclass) \
         spin_lock_irqsave(lock, flags)
 
@@ -260,16 +291,25 @@ do {						\
 } while (0)
 #endif
 
-#define spin_unlock_irqrestore(lock, flags) \
-                                        _spin_unlock_irqrestore(lock, flags)
+#define spin_unlock_irqrestore(lock, flags)             \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                _spin_unlock_irqrestore(lock, flags);   \
+        } while (0)
 #define spin_unlock_bh(lock)            _spin_unlock_bh(lock)
 
-#define read_unlock_irqrestore(lock, flags) \
-                                        _read_unlock_irqrestore(lock, flags)
+#define read_unlock_irqrestore(lock, flags)             \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                _read_unlock_irqrestore(lock, flags);   \
+        } while (0)
 #define read_unlock_bh(lock)            _read_unlock_bh(lock)
 
-#define write_unlock_irqrestore(lock, flags) \
-                                        _write_unlock_irqrestore(lock, flags)
+#define write_unlock_irqrestore(lock, flags)            \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                _write_unlock_irqrestore(lock, flags);  \
+        } while (0)
 #define write_unlock_bh(lock)           _write_unlock_bh(lock)
 
 #define spin_trylock_bh(lock)   __cond_lock(lock, _spin_trylock_bh(lock))