| Message ID | 20201210194042.703779349@linutronix.de |
|---|---|
| State | New |
| Headers | show |
| Series | genirq: Treewide hunt for irq descriptor abuse and assorted fixes | expand |
On Thu, Dec 10, 2020 at 08:25:38PM +0100, Thomas Gleixner wrote: > These checks are used by modules and prevent the removal of the export of > irq_to_desc(). Move the accessor into the core. > > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Yes, but that means that irq_check_status_bit() may be called from modules, but it is not exported, resulting in build errors such as the following. arm64:allmodconfig: ERROR: modpost: "irq_check_status_bit" [drivers/perf/arm_spe_pmu.ko] undefined! Guenter > --- > include/linux/irqdesc.h | 17 +++++------------ > kernel/irq/manage.c | 17 +++++++++++++++++ > 2 files changed, 22 insertions(+), 12 deletions(-) > > --- a/include/linux/irqdesc.h > +++ b/include/linux/irqdesc.h > @@ -223,28 +223,21 @@ irq_set_chip_handler_name_locked(struct > data->chip = chip; > } > > +bool irq_check_status_bit(unsigned int irq, unsigned int bitmask); > + > static inline bool irq_balancing_disabled(unsigned int irq) > { > - struct irq_desc *desc; > - > - desc = irq_to_desc(irq); > - return desc->status_use_accessors & IRQ_NO_BALANCING_MASK; > + return irq_check_status_bit(irq, IRQ_NO_BALANCING_MASK); > } > > static inline bool irq_is_percpu(unsigned int irq) > { > - struct irq_desc *desc; > - > - desc = irq_to_desc(irq); > - return desc->status_use_accessors & IRQ_PER_CPU; > + return irq_check_status_bit(irq, IRQ_PER_CPU); > } > > static inline bool irq_is_percpu_devid(unsigned int irq) > { > - struct irq_desc *desc; > - > - desc = irq_to_desc(irq); > - return desc->status_use_accessors & IRQ_PER_CPU_DEVID; > + return irq_check_status_bit(irq, IRQ_PER_CPU_DEVID); > } > > static inline void > --- a/kernel/irq/manage.c > +++ b/kernel/irq/manage.c > @@ -2769,3 +2769,23 @@ bool irq_has_action(unsigned int irq) > return res; > } > EXPORT_SYMBOL_GPL(irq_has_action); > + > +/** > + * irq_check_status_bit - Check whether bits in the irq descriptor status are set > + * @irq: The linux irq number > + * @bitmask: The bitmask to evaluate > + * > + * Returns: True if one of the bits in @bitmask is set > + */ > +bool irq_check_status_bit(unsigned int irq, unsigned int bitmask) > +{ > + struct irq_desc *desc; > + bool res = false; > + > + rcu_read_lock(); > + desc = irq_to_desc(irq); > + if (desc) > + res = !!(desc->status_use_accessors & bitmask); > + rcu_read_unlock(); > + return res; > +}
On Sun, Dec 27 2020 at 11:20, Guenter Roeck wrote: > On Thu, Dec 10, 2020 at 08:25:38PM +0100, Thomas Gleixner wrote: > Yes, but that means that irq_check_status_bit() may be called from modules, > but it is not exported, resulting in build errors such as the following. > > arm64:allmodconfig: > > ERROR: modpost: "irq_check_status_bit" [drivers/perf/arm_spe_pmu.ko] undefined! Duh. Yes, that lacks an export obviously. Thanks, tglx
--- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -223,28 +223,21 @@ irq_set_chip_handler_name_locked(struct data->chip = chip; } +bool irq_check_status_bit(unsigned int irq, unsigned int bitmask); + static inline bool irq_balancing_disabled(unsigned int irq) { - struct irq_desc *desc; - - desc = irq_to_desc(irq); - return desc->status_use_accessors & IRQ_NO_BALANCING_MASK; + return irq_check_status_bit(irq, IRQ_NO_BALANCING_MASK); } static inline bool irq_is_percpu(unsigned int irq) { - struct irq_desc *desc; - - desc = irq_to_desc(irq); - return desc->status_use_accessors & IRQ_PER_CPU; + return irq_check_status_bit(irq, IRQ_PER_CPU); } static inline bool irq_is_percpu_devid(unsigned int irq) { - struct irq_desc *desc; - - desc = irq_to_desc(irq); - return desc->status_use_accessors & IRQ_PER_CPU_DEVID; + return irq_check_status_bit(irq, IRQ_PER_CPU_DEVID); } static inline void --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -2769,3 +2769,23 @@ bool irq_has_action(unsigned int irq) return res; } EXPORT_SYMBOL_GPL(irq_has_action); + +/** + * irq_check_status_bit - Check whether bits in the irq descriptor status are set + * @irq: The linux irq number + * @bitmask: The bitmask to evaluate + * + * Returns: True if one of the bits in @bitmask is set + */ +bool irq_check_status_bit(unsigned int irq, unsigned int bitmask) +{ + struct irq_desc *desc; + bool res = false; + + rcu_read_lock(); + desc = irq_to_desc(irq); + if (desc) + res = !!(desc->status_use_accessors & bitmask); + rcu_read_unlock(); + return res; +}
These checks are used by modules and prevent the removal of the export of irq_to_desc(). Move the accessor into the core. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- include/linux/irqdesc.h | 17 +++++------------ kernel/irq/manage.c | 17 +++++++++++++++++ 2 files changed, 22 insertions(+), 12 deletions(-)