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-rw-r--r--lib/test_kprobes.c403
1 files changed, 403 insertions, 0 deletions
diff --git a/lib/test_kprobes.c b/lib/test_kprobes.c
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index 0000000000..0648f7154f
--- /dev/null
+++ b/lib/test_kprobes.c
@@ -0,0 +1,403 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * test_kprobes.c - simple sanity test for *probes
+ *
+ * Copyright IBM Corp. 2008
+ */
+
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+#include <linux/random.h>
+#include <kunit/test.h>
+
+#define div_factor 3
+
+static u32 rand1, preh_val, posth_val;
+static u32 (*target)(u32 value);
+static u32 (*recursed_target)(u32 value);
+static u32 (*target2)(u32 value);
+static struct kunit *current_test;
+
+static unsigned long (*internal_target)(void);
+static unsigned long (*stacktrace_target)(void);
+static unsigned long (*stacktrace_driver)(void);
+static unsigned long target_return_address[2];
+
+static noinline u32 kprobe_target(u32 value)
+{
+ return (value / div_factor);
+}
+
+static noinline u32 kprobe_recursed_target(u32 value)
+{
+ return (value / div_factor);
+}
+
+static int kp_pre_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ KUNIT_EXPECT_FALSE(current_test, preemptible());
+
+ preh_val = recursed_target(rand1);
+ return 0;
+}
+
+static void kp_post_handler(struct kprobe *p, struct pt_regs *regs,
+ unsigned long flags)
+{
+ u32 expval = recursed_target(rand1);
+
+ KUNIT_EXPECT_FALSE(current_test, preemptible());
+ KUNIT_EXPECT_EQ(current_test, preh_val, expval);
+
+ 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 void test_kprobe(struct kunit *test)
+{
+ current_test = test;
+ KUNIT_EXPECT_EQ(test, 0, register_kprobe(&kp));
+ target(rand1);
+ unregister_kprobe(&kp);
+ KUNIT_EXPECT_NE(test, 0, preh_val);
+ KUNIT_EXPECT_NE(test, 0, posth_val);
+}
+
+static noinline u32 kprobe_target2(u32 value)
+{
+ return (value / div_factor) + 1;
+}
+
+static noinline unsigned long kprobe_stacktrace_internal_target(void)
+{
+ if (!target_return_address[0])
+ target_return_address[0] = (unsigned long)__builtin_return_address(0);
+ return target_return_address[0];
+}
+
+static noinline unsigned long kprobe_stacktrace_target(void)
+{
+ if (!target_return_address[1])
+ target_return_address[1] = (unsigned long)__builtin_return_address(0);
+
+ if (internal_target)
+ internal_target();
+
+ return target_return_address[1];
+}
+
+static noinline unsigned long kprobe_stacktrace_driver(void)
+{
+ if (stacktrace_target)
+ stacktrace_target();
+
+ /* This is for preventing inlining the function */
+ return (unsigned long)__builtin_return_address(0);
+}
+
+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)
+{
+ KUNIT_EXPECT_EQ(current_test, preh_val, (rand1 / div_factor) + 1);
+ 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 void test_kprobes(struct kunit *test)
+{
+ struct kprobe *kps[2] = {&kp, &kp2};
+
+ current_test = test;
+
+ /* addr and flags should be cleard for reusing kprobe. */
+ kp.addr = NULL;
+ kp.flags = 0;
+
+ KUNIT_EXPECT_EQ(test, 0, register_kprobes(kps, 2));
+ preh_val = 0;
+ posth_val = 0;
+ target(rand1);
+
+ KUNIT_EXPECT_NE(test, 0, preh_val);
+ KUNIT_EXPECT_NE(test, 0, posth_val);
+
+ preh_val = 0;
+ posth_val = 0;
+ target2(rand1);
+
+ KUNIT_EXPECT_NE(test, 0, preh_val);
+ KUNIT_EXPECT_NE(test, 0, posth_val);
+ unregister_kprobes(kps, 2);
+}
+
+static struct kprobe kp_missed = {
+ .symbol_name = "kprobe_recursed_target",
+ .pre_handler = kp_pre_handler,
+ .post_handler = kp_post_handler,
+};
+
+static void test_kprobe_missed(struct kunit *test)
+{
+ current_test = test;
+ preh_val = 0;
+ posth_val = 0;
+
+ KUNIT_EXPECT_EQ(test, 0, register_kprobe(&kp_missed));
+
+ recursed_target(rand1);
+
+ KUNIT_EXPECT_EQ(test, 2, kp_missed.nmissed);
+ KUNIT_EXPECT_NE(test, 0, preh_val);
+ KUNIT_EXPECT_NE(test, 0, posth_val);
+
+ unregister_kprobe(&kp_missed);
+}
+
+#ifdef CONFIG_KRETPROBES
+static u32 krph_val;
+
+static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+ KUNIT_EXPECT_FALSE(current_test, preemptible());
+ 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);
+
+ KUNIT_EXPECT_FALSE(current_test, preemptible());
+ KUNIT_EXPECT_EQ(current_test, ret, rand1 / div_factor);
+ KUNIT_EXPECT_NE(current_test, krph_val, 0);
+ krph_val = rand1;
+ return 0;
+}
+
+static struct kretprobe rp = {
+ .handler = return_handler,
+ .entry_handler = entry_handler,
+ .kp.symbol_name = "kprobe_target"
+};
+
+static void test_kretprobe(struct kunit *test)
+{
+ current_test = test;
+ KUNIT_EXPECT_EQ(test, 0, register_kretprobe(&rp));
+ target(rand1);
+ unregister_kretprobe(&rp);
+ KUNIT_EXPECT_EQ(test, krph_val, rand1);
+}
+
+static int return_handler2(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+ unsigned long ret = regs_return_value(regs);
+
+ KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor) + 1);
+ KUNIT_EXPECT_NE(current_test, krph_val, 0);
+ krph_val = rand1;
+ return 0;
+}
+
+static struct kretprobe rp2 = {
+ .handler = return_handler2,
+ .entry_handler = entry_handler,
+ .kp.symbol_name = "kprobe_target2"
+};
+
+static void test_kretprobes(struct kunit *test)
+{
+ struct kretprobe *rps[2] = {&rp, &rp2};
+
+ current_test = test;
+ /* addr and flags should be cleard for reusing kprobe. */
+ rp.kp.addr = NULL;
+ rp.kp.flags = 0;
+ KUNIT_EXPECT_EQ(test, 0, register_kretprobes(rps, 2));
+
+ krph_val = 0;
+ target(rand1);
+ KUNIT_EXPECT_EQ(test, krph_val, rand1);
+
+ krph_val = 0;
+ target2(rand1);
+ KUNIT_EXPECT_EQ(test, krph_val, rand1);
+ unregister_kretprobes(rps, 2);
+}
+
+#ifdef CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
+#define STACK_BUF_SIZE 16
+static unsigned long stack_buf[STACK_BUF_SIZE];
+
+static int stacktrace_return_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+ unsigned long retval = regs_return_value(regs);
+ int i, ret;
+
+ KUNIT_EXPECT_FALSE(current_test, preemptible());
+ KUNIT_EXPECT_EQ(current_test, retval, target_return_address[1]);
+
+ /*
+ * Test stacktrace inside the kretprobe handler, this will involves
+ * kretprobe trampoline, but must include correct return address
+ * of the target function.
+ */
+ ret = stack_trace_save(stack_buf, STACK_BUF_SIZE, 0);
+ KUNIT_EXPECT_NE(current_test, ret, 0);
+
+ for (i = 0; i < ret; i++) {
+ if (stack_buf[i] == target_return_address[1])
+ break;
+ }
+ KUNIT_EXPECT_NE(current_test, i, ret);
+
+#if !IS_MODULE(CONFIG_KPROBES_SANITY_TEST)
+ /*
+ * Test stacktrace from pt_regs at the return address. Thus the stack
+ * trace must start from the target return address.
+ */
+ ret = stack_trace_save_regs(regs, stack_buf, STACK_BUF_SIZE, 0);
+ KUNIT_EXPECT_NE(current_test, ret, 0);
+ KUNIT_EXPECT_EQ(current_test, stack_buf[0], target_return_address[1]);
+#endif
+
+ return 0;
+}
+
+static struct kretprobe rp3 = {
+ .handler = stacktrace_return_handler,
+ .kp.symbol_name = "kprobe_stacktrace_target"
+};
+
+static void test_stacktrace_on_kretprobe(struct kunit *test)
+{
+ unsigned long myretaddr = (unsigned long)__builtin_return_address(0);
+
+ current_test = test;
+ rp3.kp.addr = NULL;
+ rp3.kp.flags = 0;
+
+ /*
+ * Run the stacktrace_driver() to record correct return address in
+ * stacktrace_target() and ensure stacktrace_driver() call is not
+ * inlined by checking the return address of stacktrace_driver()
+ * and the return address of this function is different.
+ */
+ KUNIT_ASSERT_NE(test, myretaddr, stacktrace_driver());
+
+ KUNIT_ASSERT_EQ(test, 0, register_kretprobe(&rp3));
+ KUNIT_ASSERT_NE(test, myretaddr, stacktrace_driver());
+ unregister_kretprobe(&rp3);
+}
+
+static int stacktrace_internal_return_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+ unsigned long retval = regs_return_value(regs);
+ int i, ret;
+
+ KUNIT_EXPECT_FALSE(current_test, preemptible());
+ KUNIT_EXPECT_EQ(current_test, retval, target_return_address[0]);
+
+ /*
+ * Test stacktrace inside the kretprobe handler for nested case.
+ * The unwinder will find the kretprobe_trampoline address on the
+ * return address, and kretprobe must solve that.
+ */
+ ret = stack_trace_save(stack_buf, STACK_BUF_SIZE, 0);
+ KUNIT_EXPECT_NE(current_test, ret, 0);
+
+ for (i = 0; i < ret - 1; i++) {
+ if (stack_buf[i] == target_return_address[0]) {
+ KUNIT_EXPECT_EQ(current_test, stack_buf[i + 1], target_return_address[1]);
+ break;
+ }
+ }
+ KUNIT_EXPECT_NE(current_test, i, ret);
+
+#if !IS_MODULE(CONFIG_KPROBES_SANITY_TEST)
+ /* Ditto for the regs version. */
+ ret = stack_trace_save_regs(regs, stack_buf, STACK_BUF_SIZE, 0);
+ KUNIT_EXPECT_NE(current_test, ret, 0);
+ KUNIT_EXPECT_EQ(current_test, stack_buf[0], target_return_address[0]);
+ KUNIT_EXPECT_EQ(current_test, stack_buf[1], target_return_address[1]);
+#endif
+
+ return 0;
+}
+
+static struct kretprobe rp4 = {
+ .handler = stacktrace_internal_return_handler,
+ .kp.symbol_name = "kprobe_stacktrace_internal_target"
+};
+
+static void test_stacktrace_on_nested_kretprobe(struct kunit *test)
+{
+ unsigned long myretaddr = (unsigned long)__builtin_return_address(0);
+ struct kretprobe *rps[2] = {&rp3, &rp4};
+
+ current_test = test;
+ rp3.kp.addr = NULL;
+ rp3.kp.flags = 0;
+
+ //KUNIT_ASSERT_NE(test, myretaddr, stacktrace_driver());
+
+ KUNIT_ASSERT_EQ(test, 0, register_kretprobes(rps, 2));
+ KUNIT_ASSERT_NE(test, myretaddr, stacktrace_driver());
+ unregister_kretprobes(rps, 2);
+}
+#endif /* CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE */
+
+#endif /* CONFIG_KRETPROBES */
+
+static int kprobes_test_init(struct kunit *test)
+{
+ target = kprobe_target;
+ target2 = kprobe_target2;
+ recursed_target = kprobe_recursed_target;
+ stacktrace_target = kprobe_stacktrace_target;
+ internal_target = kprobe_stacktrace_internal_target;
+ stacktrace_driver = kprobe_stacktrace_driver;
+ rand1 = get_random_u32_above(div_factor);
+ return 0;
+}
+
+static struct kunit_case kprobes_testcases[] = {
+ KUNIT_CASE(test_kprobe),
+ KUNIT_CASE(test_kprobes),
+ KUNIT_CASE(test_kprobe_missed),
+#ifdef CONFIG_KRETPROBES
+ KUNIT_CASE(test_kretprobe),
+ KUNIT_CASE(test_kretprobes),
+#ifdef CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
+ KUNIT_CASE(test_stacktrace_on_kretprobe),
+ KUNIT_CASE(test_stacktrace_on_nested_kretprobe),
+#endif
+#endif
+ {}
+};
+
+static struct kunit_suite kprobes_test_suite = {
+ .name = "kprobes_test",
+ .init = kprobes_test_init,
+ .test_cases = kprobes_testcases,
+};
+
+kunit_test_suites(&kprobes_test_suite);
+
+MODULE_LICENSE("GPL");