[Fault-injection-developer] [PATCH]New Mock Interceptor

[Rusty L. <ru...@li...>]

I added a new "mock" interceptor to aid in testing fi_core.c, but 
it could also be viewed as a near minimal interceptor implementation.

If you build drivers/char/fi_mock_interceptor.c as a module you can
then control what type of interceptor it will register as with a 
'mock_type' parameter.

Once the module is loaded and a new trigger is added that uses the
interceptor, then mock will create a 'trip' file in the trigger's 
sysfs directory.  Writing anything to the 'trip' file will cause
fi_execute_trigger() to be called for that trigger.

All functions print tracing information to the log, so you should be
able to trace proper interceptor/core interactions.

In implementing this I moved the definitions for trigger and interceptor
attributes to the header file, and added the missing logic to fi_core.c
to allow any interceptor to:
* add files to the trigger directories for the triggers that arm the 
  interceptor
* add files to an interceptors own interceptor directory

Have a good holidays.

        -rustyl

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
#	           ChangeSet	1.908   -> 1.910  
#	   arch/i386/Kconfig	1.24    -> 1.25   
#	    kernel/fi_core.c	1.15    -> 1.17   
#	  include/linux/fi.h	1.3     -> 1.4    
#	drivers/char/Makefile	1.54    -> 1.55   
#	               (new)	        -> 1.1     drivers/char/fi_mock_interceptor.c
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/12/20	rusty@penguin.(none)	1.885.7.1
# * Added a new interceptor just for the purpose of testing fi_core.c
# * Added support for interceptor attributes
# * Added a new interceptor unregistration function to fi_core
# --------------------------------------------
# 02/12/20	rusty@penguin.(none)	1.909
# Fixed merge conflict
# --------------------------------------------
# 02/12/20	rusty@penguin.(none)	1.910
# fixed a mistake in last merge
# --------------------------------------------
#
diff -Nru a/arch/i386/Kconfig b/arch/i386/Kconfig
--- a/arch/i386/Kconfig	Fri Dec 20 17:43:51 2002
+++ b/arch/i386/Kconfig	Fri Dec 20 17:43:51 2002
@@ -1585,6 +1585,17 @@
 	  Unless you are intending to experiment with fault injection testing,
           just say N.
 
+config FI_MOCK_INTERCEPTOR
+	tristate "Fault Injection Mock Interceptor (EXPERIMENTAL)"
+	depends on FI
+	help
+	  This is a mock or fake fault injection interceptor created for the
+	  sole purpose of exercising the fault injection core code.  The 
+          only reason a person would want to build this component is to
+          hack fault injection.
+
+          If in doubt say N.
+
 config DEBUG_STACKOVERFLOW
 	bool "Check for stack overflows"
 	depends on DEBUG_KERNEL
diff -Nru a/drivers/char/Makefile b/drivers/char/Makefile
--- a/drivers/char/Makefile	Fri Dec 20 17:43:51 2002
+++ b/drivers/char/Makefile	Fri Dec 20 17:43:51 2002
@@ -77,6 +77,7 @@
 obj-$(CONFIG_NWFLASH) += nwflash.o
 obj-$(CONFIG_SCx200_GPIO) += scx200_gpio.o
 obj-$(CONFIG_FI_TEST) += fi_test.o
+obj-$(CONFIG_FI_MOCK_INTERCEPTOR) += fi_mock_interceptor.o
 
 obj-$(CONFIG_WATCHDOG)	+= watchdog/
 obj-$(CONFIG_MWAVE) += mwave/
diff -Nru a/drivers/char/fi_mock_interceptor.c b/drivers/char/fi_mock_interceptor.c
--- /dev/null	Wed Dec 31 16:00:00 1969
+++ b/drivers/char/fi_mock_interceptor.c	Fri Dec 20 17:43:51 2002
@@ -0,0 +1,148 @@
+/*
+ * Fault Injection Mock Interceptor Driver
+ * ---------------------------------------
+ * 
+ * This is a fault injection interceptor interceptor created
+ * for the sole purpose of testing the core fault injection code. 
+ * By loading this driver a new interceptor named 'mock_interceptor' 
+ * will appear in the list of available interceptors.
+ * 
+ * When a trigger is loaded that utilizes this interceptor:
+ * - you should be able to trace of the interceptor <==> core
+ *   by looking at dmesg
+ * - a new file called 'trip' will created in the trigger directory
+ *   that when written to will trip the trigger
+ *
+ * In addition to this, the type of intercepor (interceptor_type_t)
+ * that this moc implementation claims to be when it registers
+ * with the fault injection core can be controled with the
+ * 'mock_type' parameter.
+ * 
+ * For example, to pretend to be a a INTERCEPTOR_TYPE_PIO 
+ * interceptor (which is really just the number '2' as defined
+ * in the fi.h enum declaration), you would load:
+ * $ insmod fi_mock_interceptor mod_type=2
+ *
+ * You can find out what the current type is by reading the
+ * 'type' file in the mock_interceptor directory.
+ * (i.e. 'cat fault_injection/interceptors/mock_interceptor/type')
+ *
+ * Copyright (C) 2002 Rusty Lynch <ru...@li...>
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/kobject.h>
+#include <linux/fi.h>
+
+#define DRIVER_AUTHOR	"Rusty Lynch <ru...@li...>"
+#define DRIVER_DESC	"Fault Injection Mock Interceptor"
+
+#define dbg(format, arg...) \
+		printk (KERN_DEBUG "%s: " format "\n",__FUNCTION__, ## arg);
+#define trace(format, arg...) \
+                printk(KERN_INFO "%s(" format ")\n", __FUNCTION__ , ## arg)
+
+extern int fi_register_interceptor(struct interceptor *);
+extern int fi_unregister_interceptor(struct interceptor *);
+extern void fi_execute_trigger(struct trigger*,struct interceptor*,
+			       __u32,int,int,void*);
+
+static struct interceptor mock_interceptor;
+
+/* local variables */
+static int mock_type = INTERCEPTOR_TYPE_MMIO;
+
+static ssize_t trip_store(struct trigger * p, const char * page, 
+			     size_t count, loff_t off)
+{
+	trace("%s, %p, %i, %i", p ? p->kobj.name:"NULL",page,count,(int)off);
+	fi_execute_trigger(p, &mock_interceptor, 0, 0, 0, 0);
+	return count;
+}
+static struct trigger_attribute attr_trip = {
+	.attr	= { .name = "trip", .mode = 0644 },
+	.store  = &trip_store,
+};
+
+static ssize_t type_show(struct interceptor * p, char * page, 
+			 size_t count, loff_t off)
+{
+	trace("%s, %p, %i, %i", p ? p->kobj.name:"NULL",page,count,(int)off);
+	return off ? 0 : snprintf(page,count,"%i\n",mock_type);
+}
+static struct interceptor_attribute attr_type = {
+	.attr  = { .name = "type", .mode = 0644 },
+	.show  = &type_show,
+};
+
+static int arm(struct trigger *t)
+{
+	trace("%s", t ? t->kobj.name : "NULL");
+	if (!t) {
+		dbg("Null trigger passed into arming function!");
+		return -EINVAL;
+	}
+
+	sysfs_create_file(&t->kobj, &attr_trip.attr);
+	return 0;
+};
+
+static void disarm(struct trigger *t) 
+{
+	trace("%s", t ? t->kobj.name : "NULL");
+	if (!t) {
+		dbg("Null trigger passed into disarming function!");
+		return;
+	}
+
+	sysfs_remove_file(&t->kobj, &attr_trip.attr);	
+	return;
+};
+
+static void corrupt(__u32 dirty, void *data)
+{
+	trace("%ul, %p", dirty, data);
+	return;
+};
+
+static struct interceptor mock_interceptor = {
+	.kobj    = {.name = "mock"},
+	.arm     = &arm,
+	.disarm  = &disarm,
+	.corrupt = &corrupt
+};
+
+static int __init mock_init(void)
+{
+	trace();
+
+	mock_interceptor.type = mock_type;
+	kobject_init(&mock_interceptor.kobj);
+	if (!fi_register_interceptor(&mock_interceptor)) {
+		dbg("Failed to register Mock Interceptor");
+
+		/* FIXME!! For some reason kobject_register */
+		/* is returning an error when none occured */
+		/*return -EINVAL;*/
+	}
+	
+	sysfs_create_file(&mock_interceptor.kobj, &attr_type.attr);
+	return 0;
+}
+
+static void __exit mock_exit (void)
+{
+	trace();
+	fi_unregister_interceptor(&mock_interceptor);
+}
+
+module_init(mock_init);
+module_exit(mock_exit);
+
+MODULE_PARM(mock_type, "i");
+MODULE_PARM_DESC(mock_type, "(interceptor_type_t) Type of interceptor");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
diff -Nru a/include/linux/fi.h b/include/linux/fi.h
--- a/include/linux/fi.h	Fri Dec 20 17:43:51 2002
+++ b/include/linux/fi.h	Fri Dec 20 17:43:51 2002
@@ -25,7 +25,8 @@
 typedef enum
 {
 	INTERCEPTOR_TYPE_UNKNOWN=0,
-	INTERCEPTOR_TYPE_MMIO=1
+	INTERCEPTOR_TYPE_MMIO=1,
+	INTERCEPTOR_TYPE_PIO=2,
 } interceptor_type_t;
 
 struct trigger {
@@ -54,6 +55,18 @@
 	void (*disarm) (struct trigger *);
 	void (*corrupt)(__u32, void *);
 	struct kobject kobj;
+};
+
+struct interceptor_attribute {
+	struct attribute attr;
+	ssize_t (*show) (struct interceptor *,char *,size_t,loff_t);
+	ssize_t (*store)(struct interceptor *,const char *,size_t, loff_t);
+};
+
+struct trigger_attribute {
+	struct attribute attr;
+	ssize_t (*show) (struct trigger *,char *,size_t,loff_t);
+	ssize_t (*store)(struct trigger *,const char *,size_t,loff_t);
 };
 
 #endif	/* __KERNEL__ */
diff -Nru a/kernel/fi_core.c b/kernel/fi_core.c
--- a/kernel/fi_core.c	Fri Dec 20 17:43:51 2002
+++ b/kernel/fi_core.c	Fri Dec 20 17:43:51 2002
@@ -51,16 +51,10 @@
 static struct subsystem interceptor_subsys;
 
 static int is_initialized = 0;
-
 int fi_debug = 1;
 
 int fi_register_interceptor(struct interceptor *);
 
-struct trigger_attribute {
-	struct attribute attr;
-	ssize_t (*show)(struct trigger *,char *,size_t,loff_t);
-};
-
 static struct trigger_attribute trigger_attr_wp;
 static struct trigger_attribute trigger_attr_bitmask;
 static struct trigger_attribute trigger_attr_min;
@@ -247,9 +241,42 @@
  * ---------------------------------------------------------------
  */
 
+static ssize_t interceptor_attr_show(struct kobject * kobj, 
+				     struct attribute * attr,
+				     char * page, size_t count, 
+				     loff_t off)
+{
+	struct interceptor * i = container_of(kobj,struct interceptor,kobj);
+	struct interceptor_attribute * a = 
+		container_of(attr,struct interceptor_attribute,attr);
+
+	dbg("about to call show function for %s", a->attr.name);
+	return a->show ? a->show(i,page,count,off) : 0;
+}
+
+static ssize_t interceptor_attr_store(struct kobject * kobj, 
+				      struct attribute * attr,
+				      const char * page, 
+				      size_t count, 
+				      loff_t off)
+{
+	struct interceptor * i = container_of(kobj,struct interceptor,kobj);
+	struct interceptor_attribute * a = 
+		container_of(attr,struct interceptor_attribute,attr);
+
+	dbg("about to call store function for %s", a->attr.name);
+	return a->store ? a->store(i,page,count,off) : 0;
+};
+
+static struct sysfs_ops interceptor_sysfs_ops = {
+	.show	= interceptor_attr_show,
+	.store  = interceptor_attr_store,
+};
+
 static struct subsystem interceptor_subsys = {
-	.kobj	= { .name = "interceptors" },
-	.parent = &fi_subsys,	
+	.kobj	   = { .name = "interceptors" },
+	.sysfs_ops = &interceptor_sysfs_ops,
+	.parent    = &fi_subsys,	
 };
 
 /*
@@ -271,6 +298,19 @@
 	return trigger_attr->show ? trigger_attr->show(n,page,count,off) : 0;
 }
 
+static ssize_t trigger_attr_store(struct kobject * kobj, 
+				  struct attribute * attr,
+				  const char * page, size_t count, 
+				  loff_t off)
+{
+	struct trigger * n = container_of(kobj,struct trigger,kobj);
+	struct trigger_attribute * trigger_attr = 
+		container_of(attr,struct trigger_attribute,attr);
+
+	dbg("about to call store function for %s", trigger_attr->attr.name);
+	return trigger_attr->store ? trigger_attr->store(n,page,count,off) : 0;
+}
+
 static ssize_t trigger_wp_read(struct trigger * p, char * page, 
 			       size_t count, loff_t off)
 {
@@ -497,6 +537,7 @@
 
 static struct sysfs_ops trigger_sysfs_ops = {
 	.show	= trigger_attr_show,
+	.store  = trigger_attr_store,
 };
 
 static struct subsystem trigger_subsys = {