/* * test_kprobes.c - simple sanity test for *probes * * Copyright IBM Corp. 2008 * * This program is free software;  you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it would be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See * the GNU General Public License for more details. */ #define pr_fmt(fmt) "Kprobe smoke test: " fmt #include <linux/kernel.h>#include <linux/kprobes.h>#include <linux/random.h> #define div_factor 3 static u32 rand1, preh_val, posth_val, jph_val;static int errors, handler_errors, num_tests;static u32 (*target)(u32 value);static u32 (*target2)(u32 value); static noinline u32 kprobe_target(u32 value){	return (value / div_factor);} static int kp_pre_handler(struct kprobe *p, struct pt_regs *regs){	preh_val = (rand1 / div_factor);	return 0;} static void kp_post_handler(struct kprobe *p, struct pt_regs *regs,		unsigned long flags){	if (preh_val != (rand1 / div_factor)) {		handler_errors++;		pr_err("incorrect value in post_handler\n");	}	posth_val = preh_val + div_factor;} static struct kprobe kp = {	.symbol_name = "kprobe_target",	.pre_handler = kp_pre_handler,	.post_handler = kp_post_handler}; static int test_kprobe(void){	int ret; 	ret = register_kprobe(&kp);	if (ret < 0) {		pr_err("register_kprobe returned %d\n", ret);		return ret;	} 	ret = target(rand1);	unregister_kprobe(&kp); 	if (preh_val == 0) {		pr_err("kprobe pre_handler not called\n");		handler_errors++;	} 	if (posth_val == 0) {		pr_err("kprobe post_handler not called\n");		handler_errors++;	} 	return 0;} static noinline u32 kprobe_target2(u32 value){	return (value / div_factor) + 1;} static int kp_pre_handler2(struct kprobe *p, struct pt_regs *regs){	preh_val = (rand1 / div_factor) + 1;	return 0;} static void kp_post_handler2(struct kprobe *p, struct pt_regs *regs,		unsigned long flags){	if (preh_val != (rand1 / div_factor) + 1) {		handler_errors++;		pr_err("incorrect value in post_handler2\n");	}	posth_val = preh_val + div_factor;} static struct kprobe kp2 = {	.symbol_name = "kprobe_target2",	.pre_handler = kp_pre_handler2,	.post_handler = kp_post_handler2}; static int test_kprobes(void){	int ret;	struct kprobe *kps[2] = {&kp, &kp2}; 	/* addr and flags should be cleard for reusing kprobe. */	kp.addr = NULL;	kp.flags = 0;	ret = register_kprobes(kps, 2);	if (ret < 0) {		pr_err("register_kprobes returned %d\n", ret);		return ret;	} 	preh_val = 0;	posth_val = 0;	ret = target(rand1); 	if (preh_val == 0) {		pr_err("kprobe pre_handler not called\n");		handler_errors++;	} 	if (posth_val == 0) {		pr_err("kprobe post_handler not called\n");		handler_errors++;	} 	preh_val = 0;	posth_val = 0;	ret = target2(rand1); 	if (preh_val == 0) {		pr_err("kprobe pre_handler2 not called\n");		handler_errors++;	} 	if (posth_val == 0) {		pr_err("kprobe post_handler2 not called\n");		handler_errors++;	} 	unregister_kprobes(kps, 2);	return 0; } static u32 j_kprobe_target(u32 value){	if (value != rand1) {		handler_errors++;		pr_err("incorrect value in jprobe handler\n");	} 	jph_val = rand1;	jprobe_return();	return 0;} static struct jprobe jp = {	.entry		= j_kprobe_target,	.kp.symbol_name = "kprobe_target"}; static int test_jprobe(void){	int ret; 	ret = register_jprobe(&jp);	if (ret < 0) {		pr_err("register_jprobe returned %d\n", ret);		return ret;	} 	ret = target(rand1);	unregister_jprobe(&jp);	if (jph_val == 0) {		pr_err("jprobe handler not called\n");		handler_errors++;	} 	return 0;} static struct jprobe jp2 = {	.entry          = j_kprobe_target,	.kp.symbol_name = "kprobe_target2"}; static int test_jprobes(void){	int ret;	struct jprobe *jps[2] = {&jp, &jp2}; 	/* addr and flags should be cleard for reusing kprobe. */	jp.kp.addr = NULL;	jp.kp.flags = 0;	ret = register_jprobes(jps, 2);	if (ret < 0) {		pr_err("register_jprobes returned %d\n", ret);		return ret;	} 	jph_val = 0;	ret = target(rand1);	if (jph_val == 0) {		pr_err("jprobe handler not called\n");		handler_errors++;	} 	jph_val = 0;	ret = target2(rand1);	if (jph_val == 0) {		pr_err("jprobe handler2 not called\n");		handler_errors++;	}	unregister_jprobes(jps, 2); 	return 0;}#ifdef CONFIG_KRETPROBESstatic u32 krph_val; static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs){	krph_val = (rand1 / div_factor);	return 0;} static int return_handler(struct kretprobe_instance *ri, struct pt_regs *regs){	unsigned long ret = regs_return_value(regs); 	if (ret != (rand1 / div_factor)) {		handler_errors++;		pr_err("incorrect value in kretprobe handler\n");	}	if (krph_val == 0) {		handler_errors++;		pr_err("call to kretprobe entry handler failed\n");	} 	krph_val = rand1;	return 0;} static struct kretprobe rp = {	.handler	= return_handler,	.entry_handler  = entry_handler,	.kp.symbol_name = "kprobe_target"}; static int test_kretprobe(void){	int ret; 	ret = register_kretprobe(&rp);	if (ret < 0) {		pr_err("register_kretprobe returned %d\n", ret);		return ret;	} 	ret = target(rand1);	unregister_kretprobe(&rp);	if (krph_val != rand1) {		pr_err("kretprobe handler not called\n");		handler_errors++;	} 	return 0;} static int return_handler2(struct kretprobe_instance *ri, struct pt_regs *regs){	unsigned long ret = regs_return_value(regs); 	if (ret != (rand1 / div_factor) + 1) {		handler_errors++;		pr_err("incorrect value in kretprobe handler2\n");	}	if (krph_val == 0) {		handler_errors++;		pr_err("call to kretprobe entry handler failed\n");	} 	krph_val = rand1;	return 0;} static struct kretprobe rp2 = {	.handler	= return_handler2,	.entry_handler  = entry_handler,	.kp.symbol_name = "kprobe_target2"}; static int test_kretprobes(void){	int ret;	struct kretprobe *rps[2] = {&rp, &rp2}; 	/* addr and flags should be cleard for reusing kprobe. */	rp.kp.addr = NULL;	rp.kp.flags = 0;	ret = register_kretprobes(rps, 2);	if (ret < 0) {		pr_err("register_kretprobe returned %d\n", ret);		return ret;	} 	krph_val = 0;	ret = target(rand1);	if (krph_val != rand1) {		pr_err("kretprobe handler not called\n");		handler_errors++;	} 	krph_val = 0;	ret = target2(rand1);	if (krph_val != rand1) {		pr_err("kretprobe handler2 not called\n");		handler_errors++;	}	unregister_kretprobes(rps, 2);	return 0;}#endif /* CONFIG_KRETPROBES */ int init_test_probes(void){	int ret; 	target = kprobe_target;	target2 = kprobe_target2; 	do {		rand1 = prandom_u32();	} while (rand1 <= div_factor); 	pr_info("started\n");	num_tests++;	ret = test_kprobe();	if (ret < 0)		errors++; 	num_tests++;	ret = test_kprobes();	if (ret < 0)		errors++; 	num_tests++;	ret = test_jprobe();	if (ret < 0)		errors++; 	num_tests++;	ret = test_jprobes();	if (ret < 0)		errors++; #ifdef CONFIG_KRETPROBES	num_tests++;	ret = test_kretprobe();	if (ret < 0)		errors++; 	num_tests++;	ret = test_kretprobes();	if (ret < 0)		errors++;#endif /* CONFIG_KRETPROBES */ 	if (errors)		pr_err("BUG: %d out of %d tests failed\n", errors, num_tests);	else if (handler_errors)		pr_err("BUG: %d error(s) running handlers\n", handler_errors);	else		pr_info("passed successfully\n"); 	return 0;}