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>

2 files changed, 95 insertions, 31 deletions

diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h
index 2b1c2e58566e..74bde13224c9 100644
--- a/include/linux/irqflags.h
+++ b/include/linux/irqflags.h
@@ -11,6 +11,8 @@
 #ifndef _LINUX_TRACE_IRQFLAGS_H
 #define _LINUX_TRACE_IRQFLAGS_H
 
+#include <linux/typecheck.h>
+
 #ifdef CONFIG_TRACE_IRQFLAGS
   extern void trace_softirqs_on(unsigned long ip);
   extern void trace_softirqs_off(unsigned long ip);
@@ -58,18 +60,24 @@
         do { trace_hardirqs_on(); raw_local_irq_enable(); } while (0)
 #define local_irq_disable() \
         do { raw_local_irq_disable(); trace_hardirqs_off(); } while (0)
-#define local_irq_save(flags) \
-        do { raw_local_irq_save(flags); trace_hardirqs_off(); } while (0)
+#define local_irq_save(flags)                           \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                raw_local_irq_save(flags);              \
+                trace_hardirqs_off();                   \
+        } while (0)
 
-#define local_irq_restore(flags)                                \
-        do {                                                    \
-                if (raw_irqs_disabled_flags(flags)) {           \
-                        raw_local_irq_restore(flags);           \
-                        trace_hardirqs_off();                   \
-                } else {                                        \
-                        trace_hardirqs_on();                    \
-                        raw_local_irq_restore(flags);           \
-                }                                               \
+
+#define local_irq_restore(flags)                        \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                if (raw_irqs_disabled_flags(flags)) {   \
+                        raw_local_irq_restore(flags);   \
+                        trace_hardirqs_off();           \
+                } else {                                \
+                        trace_hardirqs_on();            \
+                        raw_local_irq_restore(flags);   \
+                }                                       \
         } while (0)
 #else /* !CONFIG_TRACE_IRQFLAGS_SUPPORT */
 /*
@@ -78,8 +86,16 @@
  */
 # define raw_local_irq_disable()        local_irq_disable()
 # define raw_local_irq_enable()         local_irq_enable()
-# define raw_local_irq_save(flags)      local_irq_save(flags)
-# define raw_local_irq_restore(flags)   local_irq_restore(flags)
+# define raw_local_irq_save(flags)                      \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                local_irq_save(flags);                  \
+        } while (0)
+# define raw_local_irq_restore(flags)                   \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                local_irq_restore(flags);               \
+        } while (0)
 #endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */
 
 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
@@ -89,7 +105,11 @@
                 raw_safe_halt();                                \
         } while (0)
 
-#define local_save_flags(flags)         raw_local_save_flags(flags)
+#define local_save_flags(flags)                         \
+        do {                                            \
+                typecheck(unsigned long, flags);        \
+                raw_local_save_flags(flags);            \
+        } while (0)
 
 #define irqs_disabled()                                         \
 ({                                                              \
@@ -99,7 +119,11 @@
         raw_irqs_disabled_flags(_flags);                        \
 })
 
-#define irqs_disabled_flags(flags)      raw_irqs_disabled_flags(flags)
+#define irqs_disabled_flags(flags)              \
+({                                              \
+        typecheck(unsigned long, flags);        \
+        raw_irqs_disabled_flags(flags);         \
+})
 #endif          /* CONFIG_X86 */
 
 #endif
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))