From ee3ce191e8eaa4cc15c51a28b34143b36404c4f5 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Sat, 25 Nov 2006 11:09:36 -0800 Subject: [PATCH] Enforce "unsigned long flags;" when spinlocking Make it break or warn if you pass to spin_lock_irqsave() and friends something different from "unsigned long flags;". Suprisingly large amount of these was caught by recent commit c53421b18f205c5f97c604ae55c6a921f034b0f6 and others. Idea is largely from FRV typechecking. Suggestions from Andrew Morton. All stupid typos in first version fixed. Passes allmodconfig on i386, x86_64, alpha, arm as well as my usual config. Note #1: checking with sparse is still needed, because a driver can save and pass around flags or something. So far patch is very intrusive. Note #2: techically, we should break only if sizeof(flags) < sizeof(unsigned long), however, the more pain for getting suspicious code into kernel, the better. Signed-off-by: Alexey Dobriyan Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/spinlock.h | 53 ++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 44 insertions(+), 9 deletions(-) (limited to 'include/linux/spinlock.h') diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index b800d2d68b32..54ad37089c49 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -52,6 +52,7 @@ #include #include #include +#include #include @@ -183,13 +184,37 @@ do { \ #define read_lock(lock) _read_lock(lock) #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 { \ + BUILD_CHECK_IRQ_FLAGS(flags); \ + flags = _spin_lock_irqsave(lock); \ + } while (0) +#define read_lock_irqsave(lock, flags) \ + do { \ + BUILD_CHECK_IRQ_FLAGS(flags); \ + flags = _read_lock_irqsave(lock); \ + } while (0) +#define write_lock_irqsave(lock, flags) \ + do { \ + BUILD_CHECK_IRQ_FLAGS(flags); \ + flags = _write_lock_irqsave(lock); \ + } while (0) #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 { \ + BUILD_CHECK_IRQ_FLAGS(flags); \ + _spin_lock_irqsave(lock, flags); \ + } while (0) +#define read_lock_irqsave(lock, flags) \ + do { \ + BUILD_CHECK_IRQ_FLAGS(flags); \ + _read_lock_irqsave(lock, flags); \ + } while (0) +#define write_lock_irqsave(lock, flags) \ + do { \ + BUILD_CHECK_IRQ_FLAGS(flags); \ + _write_lock_irqsave(lock, flags); \ + } while (0) #endif #define spin_lock_irq(lock) _spin_lock_irq(lock) @@ -225,15 +250,24 @@ do { \ #endif #define spin_unlock_irqrestore(lock, flags) \ - _spin_unlock_irqrestore(lock, flags) + do { \ + BUILD_CHECK_IRQ_FLAGS(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) + do { \ + BUILD_CHECK_IRQ_FLAGS(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) + do { \ + BUILD_CHECK_IRQ_FLAGS(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)) @@ -247,6 +281,7 @@ do { \ #define spin_trylock_irqsave(lock, flags) \ ({ \ + BUILD_CHECK_IRQ_FLAGS(flags); \ local_irq_save(flags); \ spin_trylock(lock) ? \ 1 : ({ local_irq_restore(flags); 0; }); \ -- cgit v1.3-8-gc7d7 From cfd3ef2346f924d6c0e82236c20fdb3a8840136a Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Sat, 25 Nov 2006 11:09:37 -0800 Subject: [PATCH] lockdep: spin_lock_irqsave_nested() Introduce spin_lock_irqsave_nested(); implementation from: http://lkml.org/lkml/2006/6/1/122 Patch from: http://lkml.org/lkml/2006/9/13/258 [akpm@osdl.org: two compile fixes] Signed-off-by: Arjan van de Ven Signed-off-by: Jiri Kosina Signed-off-by: Peter Zijlstra Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/spinlock.h | 18 ++++++++++++++++++ include/linux/spinlock_api_smp.h | 2 ++ kernel/spinlock.c | 21 +++++++++++++++++++++ 3 files changed, 41 insertions(+) (limited to 'include/linux/spinlock.h') diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 54ad37089c49..57f670d78f7c 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -199,6 +199,21 @@ do { \ BUILD_CHECK_IRQ_FLAGS(flags); \ flags = _write_lock_irqsave(lock); \ } while (0) + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +#define spin_lock_irqsave_nested(lock, flags, subclass) \ + do { \ + BUILD_CHECK_IRQ_FLAGS(flags); \ + flags = _spin_lock_irqsave_nested(lock, subclass); \ + } while (0) +#else +#define spin_lock_irqsave_nested(lock, flags, subclass) \ + do { \ + BUILD_CHECK_IRQ_FLAGS(flags); \ + flags = _spin_lock_irqsave(lock); \ + } while (0) +#endif + #else #define spin_lock_irqsave(lock, flags) \ do { \ @@ -215,6 +230,9 @@ do { \ BUILD_CHECK_IRQ_FLAGS(flags); \ _write_lock_irqsave(lock, flags); \ } while (0) +#define spin_lock_irqsave_nested(lock, flags, subclass) \ + spin_lock_irqsave(lock, flags) + #endif #define spin_lock_irq(lock) _spin_lock_irq(lock) diff --git a/include/linux/spinlock_api_smp.h b/include/linux/spinlock_api_smp.h index 8828b8155e9c..8a2307ce7296 100644 --- a/include/linux/spinlock_api_smp.h +++ b/include/linux/spinlock_api_smp.h @@ -32,6 +32,8 @@ void __lockfunc _read_lock_irq(rwlock_t *lock) __acquires(lock); void __lockfunc _write_lock_irq(rwlock_t *lock) __acquires(lock); unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock) __acquires(lock); +unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass) + __acquires(lock); unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock) __acquires(lock); unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock) diff --git a/kernel/spinlock.c b/kernel/spinlock.c index 476c3741511b..2c6c2bf85514 100644 --- a/kernel/spinlock.c +++ b/kernel/spinlock.c @@ -293,6 +293,27 @@ void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass) } EXPORT_SYMBOL(_spin_lock_nested); +unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass) +{ + unsigned long flags; + + local_irq_save(flags); + preempt_disable(); + spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_); + /* + * On lockdep we dont want the hand-coded irq-enable of + * _raw_spin_lock_flags() code, because lockdep assumes + * that interrupts are not re-enabled during lock-acquire: + */ +#ifdef CONFIG_PROVE_SPIN_LOCKING + _raw_spin_lock(lock); +#else + _raw_spin_lock_flags(lock, &flags); +#endif + return flags; +} + +EXPORT_SYMBOL(_spin_lock_irqsave_nested); #endif -- cgit v1.3-8-gc7d7 From b8e6ec865fd1d8838b6ce9516977b65e9f08f876 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 26 Nov 2006 16:27:17 -0800 Subject: Revert "[PATCH] Enforce "unsigned long flags;" when spinlocking" This reverts commit ee3ce191e8eaa4cc15c51a28b34143b36404c4f5, since it broke on at least ARM, MIPS and PA-RISC due to complicated header file dependencies. Conflicts in include/linux/spinlock.h (due to the "nested" variety fixes) fixed up by hand. Cc: Alexey Dobriyan Cc: Ralf Baechle Cc: Kyle McMartin Cc: Russell King Signed-off-by: Linus Torvalds --- include/linux/irqflags.h | 37 ++++---------------------- include/linux/spinlock.h | 69 +++++++++++------------------------------------- 2 files changed, 20 insertions(+), 86 deletions(-) (limited to 'include/linux/spinlock.h') diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h index 4fe740bf4eae..412e025bc5c7 100644 --- a/include/linux/irqflags.h +++ b/include/linux/irqflags.h @@ -11,12 +11,6 @@ #ifndef _LINUX_TRACE_IRQFLAGS_H #define _LINUX_TRACE_IRQFLAGS_H -#define BUILD_CHECK_IRQ_FLAGS(flags) \ - do { \ - BUILD_BUG_ON(sizeof(flags) != sizeof(unsigned long)); \ - typecheck(unsigned long, flags); \ - } while (0) - #ifdef CONFIG_TRACE_IRQFLAGS extern void trace_hardirqs_on(void); extern void trace_hardirqs_off(void); @@ -56,15 +50,10 @@ #define local_irq_disable() \ do { raw_local_irq_disable(); trace_hardirqs_off(); } while (0) #define local_irq_save(flags) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - raw_local_irq_save(flags); \ - trace_hardirqs_off(); \ - } while (0) + do { raw_local_irq_save(flags); trace_hardirqs_off(); } while (0) #define local_irq_restore(flags) \ do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ if (raw_irqs_disabled_flags(flags)) { \ raw_local_irq_restore(flags); \ trace_hardirqs_off(); \ @@ -80,16 +69,8 @@ */ # define raw_local_irq_disable() local_irq_disable() # define raw_local_irq_enable() local_irq_enable() -# define raw_local_irq_save(flags) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - local_irq_save(flags); \ - } while (0) -# define raw_local_irq_restore(flags) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - local_irq_restore(flags); \ - } while (0) +# define raw_local_irq_save(flags) local_irq_save(flags) +# define raw_local_irq_restore(flags) local_irq_restore(flags) #endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */ #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT @@ -99,11 +80,7 @@ raw_safe_halt(); \ } while (0) -#define local_save_flags(flags) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - raw_local_save_flags(flags); \ - } while (0) +#define local_save_flags(flags) raw_local_save_flags(flags) #define irqs_disabled() \ ({ \ @@ -113,11 +90,7 @@ raw_irqs_disabled_flags(flags); \ }) -#define irqs_disabled_flags(flags) \ -({ \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - raw_irqs_disabled_flags(flags); \ -}) +#define irqs_disabled_flags(flags) raw_irqs_disabled_flags(flags) #endif /* CONFIG_X86 */ #endif diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 57f670d78f7c..8451052ca66f 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -52,7 +52,6 @@ #include #include #include -#include #include @@ -184,52 +183,24 @@ do { \ #define read_lock(lock) _read_lock(lock) #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) -#define spin_lock_irqsave(lock, flags) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - flags = _spin_lock_irqsave(lock); \ - } while (0) -#define read_lock_irqsave(lock, flags) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - flags = _read_lock_irqsave(lock); \ - } while (0) -#define write_lock_irqsave(lock, flags) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - flags = _write_lock_irqsave(lock); \ - } while (0) + +#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) #ifdef CONFIG_DEBUG_LOCK_ALLOC -#define spin_lock_irqsave_nested(lock, flags, subclass) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - flags = _spin_lock_irqsave_nested(lock, subclass); \ - } while (0) +#define spin_lock_irqsave_nested(lock, flags, subclass) \ + flags = _spin_lock_irqsave_nested(lock, subclass) #else -#define spin_lock_irqsave_nested(lock, flags, subclass) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - flags = _spin_lock_irqsave(lock); \ - } while (0) +#define spin_lock_irqsave_nested(lock, flags, subclass) \ + flags = _spin_lock_irqsave(lock) #endif #else -#define spin_lock_irqsave(lock, flags) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - _spin_lock_irqsave(lock, flags); \ - } while (0) -#define read_lock_irqsave(lock, flags) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - _read_lock_irqsave(lock, flags); \ - } while (0) -#define write_lock_irqsave(lock, flags) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - _write_lock_irqsave(lock, flags); \ - } while (0) + +#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_nested(lock, flags, subclass) \ spin_lock_irqsave(lock, flags) @@ -268,24 +239,15 @@ do { \ #endif #define spin_unlock_irqrestore(lock, flags) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - _spin_unlock_irqrestore(lock, flags); \ - } while (0) + _spin_unlock_irqrestore(lock, flags) #define spin_unlock_bh(lock) _spin_unlock_bh(lock) #define read_unlock_irqrestore(lock, flags) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - _read_unlock_irqrestore(lock, flags); \ - } while (0) + _read_unlock_irqrestore(lock, flags) #define read_unlock_bh(lock) _read_unlock_bh(lock) #define write_unlock_irqrestore(lock, flags) \ - do { \ - BUILD_CHECK_IRQ_FLAGS(flags); \ - _write_unlock_irqrestore(lock, flags); \ - } while (0) + _write_unlock_irqrestore(lock, flags) #define write_unlock_bh(lock) _write_unlock_bh(lock) #define spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock)) @@ -299,7 +261,6 @@ do { \ #define spin_trylock_irqsave(lock, flags) \ ({ \ - BUILD_CHECK_IRQ_FLAGS(flags); \ local_irq_save(flags); \ spin_trylock(lock) ? \ 1 : ({ local_irq_restore(flags); 0; }); \ -- cgit v1.3-8-gc7d7