Move kprobes examples to samples/ (resend)

Index: linux-2.6.23/Documentation/kprobes.txt
===================================================================
@@ -166,7 +166,8 @@ code mapping.
 The Kprobes API includes a "register" function and an "unregister"
 function for each type of probe.  Here are terse, mini-man-page
 specifications for these functions and the associated probe handlers
-that you'll write.  See the latter half of this document for examples.
+that you'll write.  See the files in the samples/kprobes/ sub-directory
+for examples.
 
 4.1 register_kprobe
 

@@ -392,220 +393,15 @@ e. Watchpoint probes (which fire on data
 
 8. Kprobes Example
 
-Here's a sample kernel module showing the use of kprobes to dump a
-stack trace and selected i386 registers when do_fork() is called.
------ cut here -----
-/*kprobe_example.c*/
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/kprobes.h>
-#include <linux/sched.h>
-
-/*For each probe you need to allocate a kprobe structure*/
-static struct kprobe kp;
-
-/*kprobe pre_handler: called just before the probed instruction is executed*/
-int handler_pre(struct kprobe *p, struct pt_regs *regs)
-{
-	printk("pre_handler: p->addr=0x%p, eip=%lx, eflags=0x%lx\n",
-		p->addr, regs->eip, regs->eflags);
-	dump_stack();
-	return 0;
-}
-
-/*kprobe post_handler: called after the probed instruction is executed*/
-void handler_post(struct kprobe *p, struct pt_regs *regs, unsigned long flags)
-{
-	printk("post_handler: p->addr=0x%p, eflags=0x%lx\n",
-		p->addr, regs->eflags);
-}
-
-/* fault_handler: this is called if an exception is generated for any
- * instruction within the pre- or post-handler, or when Kprobes
- * single-steps the probed instruction.
- */
-int handler_fault(struct kprobe *p, struct pt_regs *regs, int trapnr)
-{
-	printk("fault_handler: p->addr=0x%p, trap #%dn",
-		p->addr, trapnr);
-	/* Return 0 because we don't handle the fault. */
-	return 0;
-}
-
-static int __init kprobe_init(void)
-{
-	int ret;
-	kp.pre_handler = handler_pre;
-	kp.post_handler = handler_post;
-	kp.fault_handler = handler_fault;
-	kp.symbol_name = "do_fork";
-
-	ret = register_kprobe(&kp);
-	if (ret < 0) {
-		printk("register_kprobe failed, returned %d\n", ret);
-		return ret;
-	}
-	printk("kprobe registered\n");
-	return 0;
-}
-
-static void __exit kprobe_exit(void)
-{
-	unregister_kprobe(&kp);
-	printk("kprobe unregistered\n");
-}
-
-module_init(kprobe_init)
-module_exit(kprobe_exit)
-MODULE_LICENSE("GPL");
------ cut here -----
-
-You can build the kernel module, kprobe-example.ko, using the following
-Makefile:
------ cut here -----
-obj-m := kprobe-example.o
-KDIR := /lib/modules/$(shell uname -r)/build
-PWD := $(shell pwd)
-default:
-	$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules
-clean:
-	rm -f *.mod.c *.ko *.o
------ cut here -----
-
-$ make
-$ su -
-...
-# insmod kprobe-example.ko
-
-You will see the trace data in /var/log/messages and on the console
-whenever do_fork() is invoked to create a new process.
+See samples/kprobes/kprobe_example.c.
 
 9. Jprobes Example
 
-Here's a sample kernel module showing the use of jprobes to dump
-the arguments of do_fork().
------ cut here -----
-/*jprobe-example.c */
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/uio.h>
-#include <linux/kprobes.h>
-
-/*
- * Jumper probe for do_fork.
- * Mirror principle enables access to arguments of the probed routine
- * from the probe handler.
- */
-
-/* Proxy routine having the same arguments as actual do_fork() routine */
-long jdo_fork(unsigned long clone_flags, unsigned long stack_start,
-	      struct pt_regs *regs, unsigned long stack_size,
-	      int __user * parent_tidptr, int __user * child_tidptr)
-{
-	printk("jprobe: clone_flags=0x%lx, stack_size=0x%lx, regs=0x%p\n",
-	       clone_flags, stack_size, regs);
-	/* Always end with a call to jprobe_return(). */
-	jprobe_return();
-	/*NOTREACHED*/
-	return 0;
-}
-
-static struct jprobe my_jprobe = {
-	.entry = jdo_fork
-};
-
-static int __init jprobe_init(void)
-{
-	int ret;
-	my_jprobe.kp.symbol_name = "do_fork";
-
-	if ((ret = register_jprobe(&my_jprobe)) <0) {
-		printk("register_jprobe failed, returned %d\n", ret);
-		return -1;
-	}
-	printk("Planted jprobe at %p, handler addr %p\n",
-	       my_jprobe.kp.addr, my_jprobe.entry);
-	return 0;
-}
-
-static void __exit jprobe_exit(void)
-{
-	unregister_jprobe(&my_jprobe);
-	printk("jprobe unregistered\n");
-}
-
-module_init(jprobe_init)
-module_exit(jprobe_exit)
-MODULE_LICENSE("GPL");
------ cut here -----
-
-Build and insert the kernel module as shown in the above kprobe
-example.  You will see the trace data in /var/log/messages and on
-the console whenever do_fork() is invoked to create a new process.
-(Some messages may be suppressed if syslogd is configured to
-eliminate duplicate messages.)
+See samples/kprobes/jprobe_example.c.
 
 10. Kretprobes Example
 
-Here's a sample kernel module showing the use of return probes to
-report failed calls to sys_open().
------ cut here -----
-/*kretprobe-example.c*/
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/kprobes.h>
-
-static const char *probed_func = "sys_open";
-
-/* Return-probe handler: If the probed function fails, log the return value. */
-static int ret_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
-{
-	int retval = regs_return_value(regs);
-	if (retval < 0) {
-		printk("%s returns %d\n", probed_func, retval);
-	}
-	return 0;
-}
-
-static struct kretprobe my_kretprobe = {
-	.handler = ret_handler,
-	/* Probe up to 20 instances concurrently. */
-	.maxactive = 20
-};
-
-static int __init kretprobe_init(void)
-{
-	int ret;
-	my_kretprobe.kp.symbol_name = (char *)probed_func;
-
-	if ((ret = register_kretprobe(&my_kretprobe)) < 0) {
-		printk("register_kretprobe failed, returned %d\n", ret);
-		return -1;
-	}
-	printk("Planted return probe at %p\n", my_kretprobe.kp.addr);
-	return 0;
-}
-
-static void __exit kretprobe_exit(void)
-{
-	unregister_kretprobe(&my_kretprobe);
-	printk("kretprobe unregistered\n");
-	/* nmissed > 0 suggests that maxactive was set too low. */
-	printk("Missed probing %d instances of %s\n",
-		my_kretprobe.nmissed, probed_func);
-}
-
-module_init(kretprobe_init)
-module_exit(kretprobe_exit)
-MODULE_LICENSE("GPL");
------ cut here -----
-
-Build and insert the kernel module as shown in the above kprobe
-example.  You will see the trace data in /var/log/messages and on the
-console whenever sys_open() returns a negative value.  (Some messages
-may be suppressed if syslogd is configured to eliminate duplicate
-messages.)
+See samples/kprobes/kretprobe_example.c.
 
 For additional information on Kprobes, refer to the following URLs:
 http://www-106.ibm.com/developerworks/library/l-kprobes.html?ca=dgr-lnxw42Kprobe

Index: linux-2.6.23/samples/Kconfig
===================================================================
@@ -13,4 +13,10 @@ config SAMPLE_MARKERS
 	help
 	  This build markers example modules.
 
+config SAMPLE_KPROBES
+	tristate "Build kprobes examples -- loadable modules only"
+	depends on KPROBES && m
+	help
+	  This build several kprobes example modules.
+
 endif # SAMPLES

Index: linux-2.6.23/samples/Makefile
===================================================================
@@ -1,3 +1,3 @@
 # Makefile for Linux samples code
 
-obj-$(CONFIG_SAMPLES)	+= markers/
+obj-$(CONFIG_SAMPLES)	+= markers/ kprobes/

Index: linux-2.6.23/samples/kprobes/Makefile
===================================================================
@@ -0,0 +1,5 @@
+# builds the kprobes example kernel modules;
+# then to use one (as root):  insmod <module_name.ko>
+
+obj-$(CONFIG_SAMPLE_KPROBES) += kprobe_example.o jprobe_example.o \
+		kretprobe_example.o

Index: kernel-13nov/arch/avr32/Kconfig
===================================================================
@@ -73,6 +73,11 @@ config GENERIC_BUG
 config ARCH_SUPPORTS_KPROBES
 	def_bool y
 
+config ARCH_SUPPORTS_KRETPROBES
+	bool
+	depends on ARCH_SUPPORTS_KPROBES
+	default n
+
 source "init/Kconfig"
 
 menu "System Type and features"

Index: kernel-13nov/arch/ia64/Kconfig
===================================================================
@@ -105,6 +105,11 @@ config ARCH_SUPPORTS_OPROFILE
 config ARCH_SUPPORTS_KPROBES
 	def_bool y
 
+config ARCH_SUPPORTS_KRETPROBES
+	bool
+	depends on ARCH_SUPPORTS_KPROBES
+	default y
+
 choice
 	prompt "System type"
 	default IA64_GENERIC

Index: kernel-13nov/arch/powerpc/Kconfig
===================================================================
@@ -169,6 +169,11 @@ config ARCH_SUPPORTS_OPROFILE
 config ARCH_SUPPORTS_KPROBES
 	def_bool y
 
+config ARCH_SUPPORTS_KRETPROBES
+	bool
+	depends on ARCH_SUPPORTS_KPROBES
+	default y
+
 source "init/Kconfig"
 
 source "arch/powerpc/platforms/Kconfig"

Index: kernel-13nov/arch/s390/Kconfig
===================================================================
@@ -58,6 +58,11 @@ config ARCH_SUPPORTS_OPROFILE
 config ARCH_SUPPORTS_KPROBES
 	def_bool y
 
+config ARCH_SUPPORTS_KRETPROBES
+	bool
+	depends on ARCH_SUPPORTS_KPROBES
+	default y
+
 source "init/Kconfig"
 
 menu "Base setup"

Index: kernel-13nov/arch/sparc64/Kconfig
===================================================================
@@ -82,6 +82,11 @@ config ARCH_SUPPORTS_OPROFILE
 config ARCH_SUPPORTS_KPROBES
 	def_bool y
 
+config ARCH_SUPPORTS_KRETPROBES
+	bool
+	depends on ARCH_SUPPORTS_KPROBES
+	default n
+
 choice
 	prompt "Kernel page size"
 	default SPARC64_PAGE_SIZE_8KB

Index: kernel-13nov/arch/x86/Kconfig.i386
===================================================================
@@ -97,6 +97,11 @@ config ARCH_SUPPORTS_OPROFILE
 config ARCH_SUPPORTS_KPROBES
 	def_bool y
 
+config ARCH_SUPPORTS_KRETPROBES
+	bool
+	depends on ARCH_SUPPORTS_KPROBES
+	default y
+
 source "init/Kconfig"
 
 menu "Processor type and features"

Index: kernel-13nov/arch/x86/Kconfig.x86_64
===================================================================
@@ -139,6 +139,11 @@ config ARCH_SUPPORTS_OPROFILE
 config ARCH_SUPPORTS_KPROBES
 	def_bool y
 
+config ARCH_SUPPORTS_KRETPROBES
+	bool
+	depends on ARCH_SUPPORTS_KPROBES
+	default y
+
 source "init/Kconfig"
 
 

Index: kernel-13nov/samples/kprobes/Makefile
===================================================================
@@ -1,5 +1,8 @@
 # builds the kprobes example kernel modules;
 # then to use one (as root):  insmod <module_name.ko>
 
-obj-$(CONFIG_SAMPLE_KPROBES) += kprobe_example.o jprobe_example.o \
-		kretprobe_example.o
+obj-$(CONFIG_SAMPLE_KPROBES) += kprobe_example.o jprobe_example.o
+
+ifeq ($(CONFIG_ARCH_SUPPORTS_KRETPROBES),y)
+obj-$(CONFIG_SAMPLE_KPROBES) += kretprobe_example.o
+endif