RE: [Fault-injection-developer] RFC: KIRQ

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Thanks for your careful review and helpful comments :)
I will apply your comments to the code:)

-Stan


> -----Original Message-----
> From: Rusty Lynch [mailto:ru...@li...]
> Sent: 2002=C4=EA12=D4=C221=C8=D5 1:31
> To: Wang, Stanley; fau...@li...
> Subject: Re: [Fault-injection-developer] RFC: KIRQ
>=20
>=20
> > Hi, folks
> > I revised the KIRQ according to Rusty's comment.
> >=20
> > # This is a BitKeeper generated patch for the following project:
> > # Project Name: Linux kernel tree
> > # This patch format is intended for GNU patch command=20
> version 2.5 or higher.
> > # This patch includes the following deltas:
> > #            ChangeSet 1.901   -> 1.902 =20
> > #    arch/i386/Kconfig 1.14    -> 1.16  =20
> > # arch/i386/kernel/Makefile 1.31    -> 1.32  =20
> > #                (new)         -> 1.4     arch/i386/kernel/kirq.c
> > #                (new)         -> 1.3     include/asm-i386/kirq.h
> > #
> > # The following is the BitKeeper ChangeSet Log
> > # --------------------------------------------
> > # 02/12/20 st...@ma... 1.892.1.3
> > # Refine config file.
> > # --------------------------------------------
> > # 02/12/20 st...@ma... 1.902
> > # Merge manticore.sh.intel.com:/home/stanley/linux-2.5
> > # into manticore.sh.intel.com:/home/stanley/work/2.5-kirq
> > # --------------------------------------------
> > #
> > diff -Nru a/arch/i386/Kconfig b/arch/i386/Kconfig
> > --- a/arch/i386/Kconfig Fri Dec 20 14:24:01 2002
> > +++ b/arch/i386/Kconfig Fri Dec 20 14:24:01 2002
> > @@ -1544,6 +1544,14 @@
> >     best used in conjunction with the NMI watchdog so that spinlock
> >     deadlocks are also debuggable.
> > =20
> > +config KIRQ
> > + bool "Kernel Irq interceptor for X86(experimental)"
> > + depends on DEBUG_KERNEL && EXPERIMENTAL
> > + help
> > +   This option enable an IRQ interceptor. You can get the control
> > +   before any specified ISR is executing and decide whether it
> > +   should be executing through "register_kirq/unregister_kirq".
> > +
> >  config DEBUG_HIGHMEM
> >   bool "Highmem debugging"
> >   depends on DEBUG_KERNEL && HIGHMEM
> > diff -Nru a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile
> > --- a/arch/i386/kernel/Makefile Fri Dec 20 14:24:01 2002
> > +++ b/arch/i386/kernel/Makefile Fri Dec 20 14:24:01 2002
> > @@ -4,7 +4,7 @@
> > =20
> >  EXTRA_TARGETS :=3D head.o init_task.o
> > =20
> > -export-objs     :=3D mca.o i386_ksyms.o time.o
> > +export-objs     :=3D mca.o i386_ksyms.o time.o kirq.o
> > =20
> >  obj-y :=3D process.o semaphore.o signal.o entry.o traps.o=20
> irq.o vm86.o \
> >   ptrace.o i8259.o ioport.o ldt.o setup.o time.o sys_i386.o \
> > @@ -29,6 +29,7 @@
> >  obj-$(CONFIG_PROFILING) +=3D profile.o
> >  obj-$(CONFIG_EDD)             +=3D edd.o
> >  obj-$(CONFIG_MODULES) +=3D module.o
> > +obj-$(CONFIG_KIRQ) +=3D kirq.o
> >  obj-y +=3D sysenter.o
> > =20
> >  EXTRA_AFLAGS   :=3D -traditional
> > diff -Nru a/arch/i386/kernel/kirq.c b/arch/i386/kernel/kirq.c
> > --- /dev/null Wed Dec 31 16:00:00 1969
> > +++ b/arch/i386/kernel/kirq.c Fri Dec 20 14:24:01 2002
> > @@ -0,0 +1,103 @@
> > +/* Support for kernel irq interceptor.
> > +   (C) 2002 Stanley Wang <sta...@in...>.
> > +*/
> > +
> > +#include <linux/config.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/mm.h>
> > +#include <linux/slab.h>
> > +#include <linux/irq.h>
> > +#include <linux/interrupt.h>
> > +#include <asm/kirq.h>
> > +
> > +void kirq_handler(int irq, void *dev_id, struct pt_regs *regs)
> > +{
> > + int i;
> > + struct kirq *p =3D kirq_list + irq;
> > + if (p->handler !=3D NULL){
> > + i =3D (*(p->handler))(p, irq, dev_id, regs);
> > + if ( i =3D=3D 0 )
> > + (*(p->isr))(irq, dev_id, regs);
> > + }else{
> > + printk(KERN_ERR "Miss KIRQ handler!\n");
>=20
> This might be a little too cryptic for a system admin
> to figure out what is happening from the system log file.
>=20
> How about:
> printk(KERN_ERR "%s: Dropping unexpected interrupt #%i\n",=20
> __FUNCTION__, irq);=20
>=20
> > + }
> > + return;
> > +}
> > +
> > +int register_kirq(int irq, char *devname, kirq_handler_t handler)
> > +{
> > + struct irqaction *action;
> > + irq_desc_t *desc =3D irq_desc + irq;
> > + struct kirq *p =3D kirq_list + irq;
> > + unsigned long flags;
> > +=20
> > + if (handler =3D=3D NULL) {
> > + printk(KERN_ERR "Register KIRQ failed: Missing handler!\n");
> > + }
> > +
> > + if (p->handler) {
> > + printk(KERN_ERR "Register KIRQ failed: KIRQ already
> > exist!\n");
> > + }
>=20
> Did you mean to return an error on the conditions above?
>=20
> > +=20
> > + spin_lock_irqsave(&desc->lock,flags);
> > +=20
> > + action =3D desc->action;
> > + while (action) {
> > + if (strcmp(action->name,devname)) {
> > + action =3D action->next;
> > + }else{
> > + break;
> > + }
> > + }
> > +
> > + if (!action) {
> > + spin_unlock_irqrestore(&desc->lock,flags);
> > + return -1;=20
> > + }
> > +
> > + p->isr =3D action->handler;
> > + p->handler =3D handler;
> > + p->dev_id =3D action->dev_id;
> > +=20
> > + action->handler =3D kirq_handler;
> > +=20
> > + spin_unlock_irqrestore(&desc->lock,flags);
> > +
> > + return 0;
> > +}
> > +
> > +int unregister_kirq(int irq)
> > +{
> > + struct irqaction *action;
> > + irq_desc_t *desc =3D irq_desc + irq;
> > + struct kirq *p =3D kirq_list + irq;
> > + unsigned long flags;
> > +=20
> > + spin_lock_irqsave(&desc->lock,flags);
> > +=20
> > + action =3D desc->action;
> > + while ( action && action->dev_id !=3D p->dev_id) {
> > + action =3D action->next;
> > + }
> > +
> > + if (!action) {
> > + printk(KERN_ERR "Unregister KIRQ failed!\n");
> > + spin_unlock_irqrestore(&desc->lock,flags);
> > + return -1;
> > + }
> > +
> > + action->handler =3D p->isr;
> > +=20
> > + p->isr =3D NULL;
> > + p->handler =3D NULL;
> > + p->dev_id =3D NULL;
> > +=20
> > + spin_unlock_irqrestore(&desc->lock,flags);
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(register_kirq);
> > +EXPORT_SYMBOL_GPL(unregister_kirq);
> > +
> > diff -Nru a/include/asm-i386/kirq.h b/include/asm-i386/kirq.h
> > --- /dev/null Wed Dec 31 16:00:00 1969
> > +++ b/include/asm-i386/kirq.h Fri Dec 20 14:24:01 2002
> > @@ -0,0 +1,28 @@
> > +#ifndef _ASM_KIRQ_H
> > +#define _ASM_KIRQ_H
> > +
> > +#include <linux/errno.h>
> > +
> > +/* Define return value for kirq handler. */
> > +#define KIRQ_CONTINUE 0
> > +#define KIRQ_SKIP 1
> > +
> > +struct kirq;
> > +typedef int (*kirq_handler_t)(struct kirq *, int, void *,=20
> struct pt_regs
> > *);
> > +struct kirq {
> > + void *dev_id;
> > + void (*isr)(int, void *, struct pt_regs *);
> > + kirq_handler_t handler;
> > +};
> > +
> > +struct kirq kirq_list[NR_IRQS] =3D
> > + { [0 ... NR_IRQS-1] =3D { NULL, NULL, NULL}};
> > +
> > +#ifdef CONFIG_KIRQ
> > +extern int register_kirq(int irq, char *devname,=20
> kirq_handler_t handler);
> > +extern int unregister_kirq(int irq);
> > +#else
> > +int register_kirq(int irq, char *devname, kirq_handler_t=20
> handler) { return
> > -ENOSYS; }
> > +int unregister_kirq(int irq) {}
> > +#endif /*CONFIG_KIRQ*/
> > +#endif /*_ASM_KIRQ_H*/
> >=20
> > Your Sincerely,
> > Stanley Wang=20
> >=20
> > SW Engineer, Intel Corporation.
> > Intel China Software Lab.=20
> > Tel: 021-52574545 ext. 1171=20
> > iNet: 8-752-1171=20
> > =20
> > Opinions expressed are those of the author and do not=20
> represent Intel
> > Corporation
> >=20
> >=20
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> >=20
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