Re: [PATCH v7 04/11] arm: Support restart through restart handler call chain

[Guenter Roeck <linux@roeck-us.net>]

On Fri, Aug 22, 2014 at 03:32:42AM +0200, Andreas Färber wrote:
> Hi,
> 
> Am 20.08.2014 02:45, schrieb Guenter Roeck:
> > The kernel core now supports a restart handler call chain for system
> > restart functions.
> > 
> > With this change, the arm_pm_restart callback is now optional, so
> > drop its initialization and check if it is set before calling it.
> > Only call the kernel restart handler if arm_pm_restart is not set.
> [...]
> > diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
> > index 81ef686..ea279f7 100644
> > --- a/arch/arm/kernel/process.c
> > +++ b/arch/arm/kernel/process.c
> > @@ -114,17 +114,13 @@ void soft_restart(unsigned long addr)
> >  	BUG();
> >  }
> >  
> > -static void null_restart(enum reboot_mode reboot_mode, const char *cmd)
> > -{
> > -}
> > -
> >  /*
> >   * Function pointers to optional machine specific functions
> >   */
> >  void (*pm_power_off)(void);
> >  EXPORT_SYMBOL(pm_power_off);
> >  
> > -void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd) = null_restart;
> > +void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
> 
> Stupid newbie question maybe, but isn't this variable uninitialized now,
> like any non-static variable in C99? Or does the kernel assure that all
> such "fields" are zero-initialized?
> 
It is initialized with NULL, like all other global and static variables in the
kernel (and like pm_power_off a few lines above).

Guenter