On Mon, Apr 16, 2007 at 09:24:21PM +0100, Russell King wrote: > On Fri, Apr 13, 2007 at 05:50:43PM +0400, Anton Vorontsov wrote: > > +static void (*old_apm_get_power_status)(struct apm_power_info*); > > + > > +static int __init apm_battery_init(void) > > +{ > > + printk(KERN_INFO "APM Battery Driver\n"); > > + > > + old_apm_get_power_status = apm_get_power_status; > > + apm_get_power_status = apm_battery_apm_get_power_status; > > + return 0; > > +} > > + > > +static void __exit apm_battery_exit(void) > > +{ > > + apm_get_power_status = old_apm_get_power_status; > > + return; > > +} > > Utterly unsafe. What happens if some other module gets loaded which > does this, and then this module is unloaded followed by the other > module. Result: Oops.
Right. And loading two modules which changing apm_get_power_status is a race already. Thus, APM interface needs a mutex. Or pda_power should be marked "bool" in Kconfig, as it is done in arch/arm/common/sharpsl_pm.c. Sharpsl_pm is safe only because it can't be a module. Personally I'd keep things as is for now (i.e. I'd want tristate for PDA_POWER, not bool). Later APM API can be fixed. > -- > Russell King > Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ > maintainer of: > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [EMAIL PROTECTED] > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > > Thanks, -- Anton Vorontsov email: [EMAIL PROTECTED] backup email: [EMAIL PROTECTED] irc://irc.freenode.org/bd2 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/