[PATCH v2 02/10] ARM: kprobes: Add basic API tests
Tixy
tixy at yxit.co.uk
Sat Sep 10 07:04:58 EDT 2011
From: Jon Medhurst <tixy at yxit.co.uk>
These test that the different kinds of probes can be successfully placed
into ARM and Thumb code and that the handlers are called correctly when
this code is executed.
Signed-off-by: Jon Medhurst <tixy at yxit.co.uk>
---
arch/arm/kernel/Makefile | 2 +
arch/arm/kernel/kprobes-test.c | 340 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 342 insertions(+), 0 deletions(-)
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index f7887dc..c7cbd96 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -43,6 +43,8 @@ obj-$(CONFIG_KPROBES) += kprobes-thumb.o
else
obj-$(CONFIG_KPROBES) += kprobes-arm.o
endif
+obj-$(CONFIG_ARM_KPROBES_TEST) += test-kprobes.o
+test-kprobes-objs := kprobes-test.o
obj-$(CONFIG_ATAGS_PROC) += atags.o
obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o
obj-$(CONFIG_ARM_THUMBEE) += thumbee.o
diff --git a/arch/arm/kernel/kprobes-test.c b/arch/arm/kernel/kprobes-test.c
new file mode 100644
index 0000000..9fff044
--- /dev/null
+++ b/arch/arm/kernel/kprobes-test.c
@@ -0,0 +1,340 @@
+/*
+ * arch/arm/kernel/kprobes-test.c
+ *
+ * Copyright (C) 2011 Jon Medhurst <tixy at yxit.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/kprobes.h>
+
+#include "kprobes.h"
+
+
+/*
+ * Test basic API
+ */
+
+static bool test_regs_ok;
+static int test_func_instance;
+static int pre_handler_called;
+static int post_handler_called;
+static int jprobe_func_called;
+static int kretprobe_handler_called;
+
+#define FUNC_ARG1 0x12345678
+#define FUNC_ARG2 0xabcdef
+
+
+#ifndef CONFIG_THUMB2_KERNEL
+
+long arm_func(long r0, long r1);
+
+static void __used __naked __arm_kprobes_test_func(void)
+{
+ __asm__ __volatile__ (
+ ".arm \n\t"
+ ".type arm_func, %%function \n\t"
+ "arm_func: \n\t"
+ "adds r0, r0, r1 \n\t"
+ "bx lr \n\t"
+ ".code "NORMAL_ISA /* Back to Thumb if necessary */
+ : : : "r0", "r1", "cc"
+ );
+}
+
+#else /* CONFIG_THUMB2_KERNEL */
+
+long thumb16_func(long r0, long r1);
+long thumb32even_func(long r0, long r1);
+long thumb32odd_func(long r0, long r1);
+
+static void __used __naked __thumb_kprobes_test_funcs(void)
+{
+ __asm__ __volatile__ (
+ ".type thumb16_func, %%function \n\t"
+ "thumb16_func: \n\t"
+ "adds.n r0, r0, r1 \n\t"
+ "bx lr \n\t"
+
+ ".align \n\t"
+ ".type thumb32even_func, %%function \n\t"
+ "thumb32even_func: \n\t"
+ "adds.w r0, r0, r1 \n\t"
+ "bx lr \n\t"
+
+ ".align \n\t"
+ "nop.n \n\t"
+ ".type thumb32odd_func, %%function \n\t"
+ "thumb32odd_func: \n\t"
+ "adds.w r0, r0, r1 \n\t"
+ "bx lr \n\t"
+
+ : : : "r0", "r1", "cc"
+ );
+}
+
+#endif /* CONFIG_THUMB2_KERNEL */
+
+
+static int call_test_func(long (*func)(long, long), bool check_test_regs)
+{
+ long ret;
+
+ ++test_func_instance;
+ test_regs_ok = false;
+
+ ret = (*func)(FUNC_ARG1, FUNC_ARG2);
+ if (ret != FUNC_ARG1 + FUNC_ARG2) {
+ pr_err("FAIL: call_test_func: func returned %lx\n", ret);
+ return false;
+ }
+
+ if (check_test_regs && !test_regs_ok) {
+ pr_err("FAIL: test regs not OK\n");
+ return false;
+ }
+
+ return true;
+}
+
+static int __kprobes pre_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ pre_handler_called = test_func_instance;
+ if (regs->ARM_r0 == FUNC_ARG1 && regs->ARM_r1 == FUNC_ARG2)
+ test_regs_ok = true;
+ return 0;
+}
+
+static void __kprobes post_handler(struct kprobe *p, struct pt_regs *regs,
+ unsigned long flags)
+{
+ post_handler_called = test_func_instance;
+ if (regs->ARM_r0 != FUNC_ARG1 + FUNC_ARG2 || regs->ARM_r1 != FUNC_ARG2)
+ test_regs_ok = false;
+}
+
+static struct kprobe the_kprobe = {
+ .addr = 0,
+ .pre_handler = pre_handler,
+ .post_handler = post_handler
+};
+
+static int test_kprobe(long (*func)(long, long))
+{
+ int ret;
+
+ the_kprobe.addr = (kprobe_opcode_t *)func;
+ ret = register_kprobe(&the_kprobe);
+ if (ret < 0) {
+ pr_err("FAIL: register_kprobe failed with %d\n", ret);
+ return ret;
+ }
+
+ ret = call_test_func(func, true);
+
+ unregister_kprobe(&the_kprobe);
+ the_kprobe.flags = 0; /* Clear disable flag to allow reuse */
+
+ if (!ret)
+ return -EINVAL;
+ if (pre_handler_called != test_func_instance) {
+ pr_err("FAIL: kprobe pre_handler not called\n");
+ return -EINVAL;
+ }
+ if (post_handler_called != test_func_instance) {
+ pr_err("FAIL: kprobe post_handler not called\n");
+ return -EINVAL;
+ }
+ if (!call_test_func(func, false))
+ return -EINVAL;
+ if (pre_handler_called == test_func_instance ||
+ post_handler_called == test_func_instance) {
+ pr_err("FAIL: probe called after unregistering\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void __kprobes jprobe_func(long r0, long r1)
+{
+ jprobe_func_called = test_func_instance;
+ if (r0 == FUNC_ARG1 && r1 == FUNC_ARG2)
+ test_regs_ok = true;
+ jprobe_return();
+}
+
+static struct jprobe the_jprobe = {
+ .entry = jprobe_func,
+};
+
+static int test_jprobe(long (*func)(long, long))
+{
+ int ret;
+
+ the_jprobe.kp.addr = (kprobe_opcode_t *)func;
+ ret = register_jprobe(&the_jprobe);
+ if (ret < 0) {
+ pr_err("FAIL: register_jprobe failed with %d\n", ret);
+ return ret;
+ }
+
+ ret = call_test_func(func, true);
+
+ unregister_jprobe(&the_jprobe);
+ the_jprobe.kp.flags = 0; /* Clear disable flag to allow reuse */
+
+ if (!ret)
+ return -EINVAL;
+ if (jprobe_func_called != test_func_instance) {
+ pr_err("FAIL: jprobe handler function not called\n");
+ return -EINVAL;
+ }
+ if (!call_test_func(func, false))
+ return -EINVAL;
+ if (jprobe_func_called == test_func_instance) {
+ pr_err("FAIL: probe called after unregistering\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int __kprobes
+kretprobe_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+ kretprobe_handler_called = test_func_instance;
+ if (regs_return_value(regs) == FUNC_ARG1 + FUNC_ARG2)
+ test_regs_ok = true;
+ return 0;
+}
+
+static struct kretprobe the_kretprobe = {
+ .handler = kretprobe_handler,
+};
+
+static int test_kretprobe(long (*func)(long, long))
+{
+ int ret;
+
+ the_kretprobe.kp.addr = (kprobe_opcode_t *)func;
+ ret = register_kretprobe(&the_kretprobe);
+ if (ret < 0) {
+ pr_err("FAIL: register_kretprobe failed with %d\n", ret);
+ return ret;
+ }
+
+ ret = call_test_func(func, true);
+
+ unregister_kretprobe(&the_kretprobe);
+ the_kretprobe.kp.flags = 0; /* Clear disable flag to allow reuse */
+
+ if (!ret)
+ return -EINVAL;
+ if (kretprobe_handler_called != test_func_instance) {
+ pr_err("FAIL: kretprobe handler not called\n");
+ return -EINVAL;
+ }
+ if (!call_test_func(func, false))
+ return -EINVAL;
+ if (jprobe_func_called == test_func_instance) {
+ pr_err("FAIL: kretprobe called after unregistering\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int run_api_tests(long (*func)(long, long))
+{
+ int ret;
+
+ pr_info(" kprobe\n");
+ ret = test_kprobe(func);
+ if (ret < 0)
+ return ret;
+
+ pr_info(" jprobe\n");
+ ret = test_jprobe(func);
+ if (ret < 0)
+ return ret;
+
+ pr_info(" kretprobe\n");
+ ret = test_kretprobe(func);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+
+/*
+ * Top level test functions
+ */
+
+static int __init run_all_tests(void)
+{
+ int ret = 0;
+
+ pr_info("Begining kprobe tests...\n");
+
+#ifndef CONFIG_THUMB2_KERNEL
+
+ pr_info("Probe ARM code\n");
+ ret = run_api_tests(arm_func);
+ if (ret)
+ goto out;
+
+#else /* CONFIG_THUMB2_KERNEL */
+
+ pr_info("Probe 16-bit Thumb code\n");
+ ret = run_api_tests(thumb16_func);
+ if (ret)
+ goto out;
+
+ pr_info("Probe 32-bit Thumb code, even halfword\n");
+ ret = run_api_tests(thumb32even_func);
+ if (ret)
+ goto out;
+
+ pr_info("Probe 32-bit Thumb code, odd halfword\n");
+ ret = run_api_tests(thumb32odd_func);
+ if (ret)
+ goto out;
+
+#endif
+
+out:
+ if (ret == 0)
+ pr_info("Finished kprobe tests OK\n");
+ else
+ pr_err("kprobe tests failed\n");
+
+ return ret;
+}
+
+
+/*
+ * Module setup
+ */
+
+#ifdef MODULE
+
+static void __exit kprobe_test_exit(void)
+{
+}
+
+module_init(run_all_tests)
+module_exit(kprobe_test_exit)
+MODULE_LICENSE("GPL");
+
+#else /* !MODULE */
+
+late_initcall(run_all_tests);
+
+#endif
--
1.7.2.5
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