kernel-fxtec-pro1x/kernel/irq/internals.h
Thomas Gleixner c1ee626428 genirq: Prevent access beyond allocated_irqs bitmap
Lars-Peter Clausen pointed out:

   I stumbled upon this while looking through the existing archs using
   SPARSE_IRQ.  Even with SPARSE_IRQ the NR_IRQS is still the upper
   limit for the number of IRQs.

   Both PXA and MMP set NR_IRQS to IRQ_BOARD_START, with
   IRQ_BOARD_START being the number of IRQs used by the core.

   In various machine files the nr_irqs field of the ARM machine
   defintion struct is then set to "IRQ_BOARD_START + NR_BOARD_IRQS".

   As a result "nr_irqs" will greater then NR_IRQS which then again
   causes the "allocated_irqs" bitmap in the core irq code to be
   accessed beyond its size overwriting unrelated data.

The core code really misses a sanity check there.

This went unnoticed so far as by chance the compiler/linker places
data behind that bitmap which gets initialized later on those affected
platforms.

So the obvious fix would be to add a sanity check in early_irq_init()
and break all affected platforms. Though that check wants to be
backported to stable as well, which will require to fix all known
problematic platforms and probably some more yet not known ones as
well. Lots of churn.

A way simpler solution is to allocate a slightly larger bitmap and
avoid the whole churn w/o breaking anything. Add a few warnings when
an arch returns utter crap.

Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org # .37
Cc: Haojian Zhuang <haojian.zhuang@marvell.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
2011-02-19 12:10:51 +01:00

112 lines
3.4 KiB
C

/*
* IRQ subsystem internal functions and variables:
*/
#include <linux/irqdesc.h>
#ifdef CONFIG_SPARSE_IRQ
# define IRQ_BITMAP_BITS (NR_IRQS + 8196)
#else
# define IRQ_BITMAP_BITS NR_IRQS
#endif
extern int noirqdebug;
#define irq_data_to_desc(data) container_of(data, struct irq_desc, irq_data)
/* Set default functions for irq_chip structures: */
extern void irq_chip_set_defaults(struct irq_chip *chip);
/* Set default handler: */
extern void compat_irq_chip_set_default_handler(struct irq_desc *desc);
extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
unsigned long flags);
extern void __disable_irq(struct irq_desc *desc, unsigned int irq, bool susp);
extern void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume);
extern void init_kstat_irqs(struct irq_desc *desc, int node, int nr);
/* Resending of interrupts :*/
void check_irq_resend(struct irq_desc *desc, unsigned int irq);
#ifdef CONFIG_PROC_FS
extern void register_irq_proc(unsigned int irq, struct irq_desc *desc);
extern void unregister_irq_proc(unsigned int irq, struct irq_desc *desc);
extern void register_handler_proc(unsigned int irq, struct irqaction *action);
extern void unregister_handler_proc(unsigned int irq, struct irqaction *action);
#else
static inline void register_irq_proc(unsigned int irq, struct irq_desc *desc) { }
static inline void unregister_irq_proc(unsigned int irq, struct irq_desc *desc) { }
static inline void register_handler_proc(unsigned int irq,
struct irqaction *action) { }
static inline void unregister_handler_proc(unsigned int irq,
struct irqaction *action) { }
#endif
extern int irq_select_affinity_usr(unsigned int irq);
extern void irq_set_thread_affinity(struct irq_desc *desc);
#ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
static inline void irq_end(unsigned int irq, struct irq_desc *desc)
{
if (desc->irq_data.chip && desc->irq_data.chip->end)
desc->irq_data.chip->end(irq);
}
#else
static inline void irq_end(unsigned int irq, struct irq_desc *desc) { }
#endif
/* Inline functions for support of irq chips on slow busses */
static inline void chip_bus_lock(struct irq_desc *desc)
{
if (unlikely(desc->irq_data.chip->irq_bus_lock))
desc->irq_data.chip->irq_bus_lock(&desc->irq_data);
}
static inline void chip_bus_sync_unlock(struct irq_desc *desc)
{
if (unlikely(desc->irq_data.chip->irq_bus_sync_unlock))
desc->irq_data.chip->irq_bus_sync_unlock(&desc->irq_data);
}
/*
* Debugging printout:
*/
#include <linux/kallsyms.h>
#define P(f) if (desc->status & f) printk("%14s set\n", #f)
static inline void print_irq_desc(unsigned int irq, struct irq_desc *desc)
{
printk("irq %d, desc: %p, depth: %d, count: %d, unhandled: %d\n",
irq, desc, desc->depth, desc->irq_count, desc->irqs_unhandled);
printk("->handle_irq(): %p, ", desc->handle_irq);
print_symbol("%s\n", (unsigned long)desc->handle_irq);
printk("->irq_data.chip(): %p, ", desc->irq_data.chip);
print_symbol("%s\n", (unsigned long)desc->irq_data.chip);
printk("->action(): %p\n", desc->action);
if (desc->action) {
printk("->action->handler(): %p, ", desc->action->handler);
print_symbol("%s\n", (unsigned long)desc->action->handler);
}
P(IRQ_INPROGRESS);
P(IRQ_DISABLED);
P(IRQ_PENDING);
P(IRQ_REPLAY);
P(IRQ_AUTODETECT);
P(IRQ_WAITING);
P(IRQ_LEVEL);
P(IRQ_MASKED);
#ifdef CONFIG_IRQ_PER_CPU
P(IRQ_PER_CPU);
#endif
P(IRQ_NOPROBE);
P(IRQ_NOREQUEST);
P(IRQ_NOAUTOEN);
}
#undef P