<<snip>>
> > > > > > From: Evgeny Kuznetsov <[email protected]> > > > > > > Value of "isr_reg" pointer is depend on configuration and GPIO method. > > > Potentially it may have NULL value and it is dereferenced later > > > in code. If pointer is NULL there is some kernel issue. > > > > Can you elaborate? > "isr_reg" should not be NULL. But if it is NULL then there is kernel > bug. And WARN_ON() used to show it. > I did not see this bug, this is potentially may happen. > > > > > Warning and exit from function are added in this case. > > > Also compilation check is added for correct architecture > > > configuration. > > > > > > Signed-off-by: Evgeny Kuznetsov <[email protected]> > > > --- > > > arch/arm/plat-omap/gpio.c | 18 ++++++++++++++++++ > > > 1 files changed, 18 insertions(+), 0 deletions(-) > > > > > > diff --git a/arch/arm/plat-omap/gpio.c b/arch/arm/plat-omap/gpio.c > > > index c05c653..d04913c 100644 > > > --- a/arch/arm/plat-omap/gpio.c > > > +++ b/arch/arm/plat-omap/gpio.c > > > @@ -1318,6 +1318,23 @@ static void gpio_irq_handler(unsigned int irq, > > > struct irq_desc *desc) > > > if (bank->method == METHOD_GPIO_44XX) > > > isr_reg = bank->base + OMAP4_GPIO_IRQSTATUS0; > > > #endif > > > + > > > +#if !defined(CONFIG_ARCH_OMAP1) && \ > > > + !defined(CONFIG_ARCH_OMAP15XX) && \ > > > + !defined(CONFIG_ARCH_OMAP16XX) && \ > > > + !defined(CONFIG_ARCH_OMAP730) && \ > > > + !defined(CONFIG_ARCH_OMAP850) && \ > > > + !defined(CONFIG_ARCH_OMAP2) && \ > > > + !defined(CONFIG_ARCH_OMAP3) && \ > > > + !defined(CONFIG_ARCH_OMAP4) > > > + > > > +#error "Incorrect arch configuration" > > > > This is not required. If the architecture is not one of the above > > mentioned, gpio_irq_handler() will not be used/called at all. > This could be removed. > > > Also all the possible gpio methods for a given OMAP architecture are > > already considered with "#ifdef"s and (bank->method) checks in > > gpio_irq_handler(). > It is not cover all cased, e.g. for OMAP4 arch: > .... > #if defined(CONFIG_ARCH_OMAP4) > if (bank->method == METHOD_GPIO_44XX) > isr_reg = bank->base + OMAP4_GPIO_IRQSTATUS0; > #endif > ..... > > If (bank->method != METHOD_GPIO_44XX) then isr_reg will be NULL. > This should not happen, but potentially may have place. When would it fail? If it is CONFIG_ARCH_OMAP4, the gpio method can only be METHOD_GPIO_44XX. Else if it is for some other OMAP architecture, the gpio_method is similarly taken care. So this cannot happen. > > > > > > + > > > +#endif > > > + > > > + if (WARN_ON(!isr_reg)) > > > + goto exit; > > > > For the above mentioned reason, this isr_reg would be non-NULL. Have > > you observed this error anytime? > I did not see this bug, this is potentially may happen. > > > > Also, the omap-gpio code has similar code spread all over and has to be > > anyway cleaned-up. Is there any reason why gpio_irq_handler() alone is > > addressed in this patch? > Here "isr_reg" is used later in code and may cause oops if it is NULL. > > > > > + > > > while(1) { > > > u32 isr_saved, level_mask = 0; > > > u32 enabled; > > > @@ -1377,6 +1394,7 @@ static void gpio_irq_handler(unsigned int irq, > > > struct irq_desc *desc) > > > configured, we must unmask the bank interrupt only after > > > handler(s) are executed in order to avoid spurious bank > > > interrupt */ > > > +exit: > > > if (!unmasked) > > > desc->chip->unmask(irq); > > > > > > -- > > > 1.6.3.3 > > > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
