Re: [patch 1/2] spinlocks: check spinlock_t/rwlock_t argument typeon non-SMP builds

[Ingo Molnar]

* akpm@xxxxxxxxxxxxxxxxxxxx <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> From: David Kilroy <kilroyd@xxxxxxxxxxxxxx>
> 
> When writing code for UP without CONFIG_DEBUG_SPINLOCK it's easy to get
> the first argument to the spinlock/rwlock functions wrong.  This is
> because the parameter is not actually used in this configuration.
> 
> Typically you will only find out it's wrong
>  * by rebuilding with CONFIG_SMP or CONFIG_DEBUG_SPINLOCK
>  * after you've submitted your beautiful patch series.
> 
> The first means a long wait, and the latter is a bit late.
> 
> Change the intermediate macros into inline functions.
> 
> Signed-off-by: David Kilroy <kilroyd@xxxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxx>
> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> ---
> 
>  include/linux/spinlock.h        |    6 -
>  include/linux/spinlock_api_up.h |  118 ++++++++++++++++++++++--------
>  2 files changed, 92 insertions(+), 32 deletions(-)
> 
> diff -puN include/linux/spinlock.h~spinlocks-check-spinlock_t-rwlock_t-argument-type-on-non-smp-builds include/linux/spinlock.h
> --- a/include/linux/spinlock.h~spinlocks-check-spinlock_t-rwlock_t-argument-type-on-non-smp-builds
> +++ a/include/linux/spinlock.h
> @@ -240,17 +240,17 @@ static inline void smp_mb__after_lock(vo
>  #define spin_lock_irqsave(lock, flags)			\
>  	do {						\
>  		typecheck(unsigned long, flags);	\
> -		_spin_lock_irqsave(lock, flags);	\
> +		_spin_lock_irqsave(lock, &flags);	\
>  	} while (0)
>  #define read_lock_irqsave(lock, flags)			\
>  	do {						\
>  		typecheck(unsigned long, flags);	\
> -		_read_lock_irqsave(lock, flags);	\
> +		_read_lock_irqsave(lock, &flags);	\
>  	} while (0)

these bits broke the Alpha build:

/home/mingo/tip/arch/alpha/include/asm/core_t2.h: In function 't2_readb':
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:451: error: '_spin_lock_irqsave' is static but used in inline function 't2_readb' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:456: error: '_spin_unlock_irqrestore' is static but used in inline function 't2_readb' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h: In function 't2_readw':
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:465: error: '_spin_lock_irqsave' is static but used in inline function 't2_readw' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:470: error: '_spin_unlock_irqrestore' is static but used in inline function 't2_readw' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h: In function 't2_readl':
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:483: error: '_spin_lock_irqsave' is static but used in inline function 't2_readl' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:488: error: '_spin_unlock_irqrestore' is static but used in inline function 't2_readl' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h: In function 't2_readq':
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:497: error: '_spin_lock_irqsave' is static but used in inline function 't2_readq' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:504: error: '_spin_unlock_irqrestore' is static but used in inline function 't2_readq' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h: In function 't2_writeb':
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:513: error: '_spin_lock_irqsave' is static but used in inline function 't2_writeb' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:519: error: '_spin_unlock_irqrestore' is static but used in inline function 't2_writeb' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h: In function 't2_writew':
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:527: error: '_spin_lock_irqsave' is static but used in inline function 't2_writew' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:533: error: '_spin_unlock_irqrestore' is static but used in inline function 't2_writew' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h: In function 't2_writel':
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:545: error: '_spin_lock_irqsave' is static but used in inline function 't2_writel' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:550: error: '_spin_unlock_irqrestore' is static but used in inline function 't2_writel' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h: In function 't2_writeq':
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:558: error: '_spin_lock_irqsave' is static but used in inline function 't2_writeq' which is not static
/home/mingo/tip/arch/alpha/include/asm/core_t2.h:565: error: '_spin_unlock_irqrestore' is static but used in inline function 't2_writeq' which is not static
make[2]: *** [arch/alpha/kernel/sys_sable.o] Error 1
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [arch/alpha/kernel] Error 2
make[1]: *** Waiting for unfinished jobs....

so i've dropped them for now.

	Ingo
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