[PATCH] add typecheck on irqsave and friends for correct flags

From: Steven Rostedt
Date: Thu May 01 2008 - 19:51:42 EST



There has 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.

Signed-off-by: Steven Rostedt <srostedt@xxxxxxxxxx>
---
include/linux/irqflags.h | 52 ++++++++++++++++++++++++----------
include/linux/spinlock.h | 71 ++++++++++++++++++++++++++++++++++++-----------
2 files changed, 92 insertions(+), 31 deletions(-)

Index: linux-compile.git/include/linux/irqflags.h
===================================================================
--- linux-compile.git.orig/include/linux/irqflags.h 2008-05-01 18:52:52.000000000 -0400
+++ linux-compile.git/include/linux/irqflags.h 2008-05-01 19:21:05.000000000 -0400
@@ -49,18 +49,24 @@
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 */
/*
@@ -69,8 +75,16 @@
*/
# 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
@@ -80,7 +94,11 @@
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() \
({ \
@@ -90,7 +108,11 @@
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
Index: linux-compile.git/include/linux/spinlock.h
===================================================================
--- linux-compile.git.orig/include/linux/spinlock.h 2008-05-01 16:58:58.000000000 -0400
+++ linux-compile.git/include/linux/spinlock.h 2008-05-01 19:16:21.000000000 -0400
@@ -191,23 +191,53 @@ 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 +290,25 @@ 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))

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