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Diffstat (limited to 'kernel/test_kprobes.c')
-rw-r--r--kernel/test_kprobes.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/kernel/test_kprobes.c b/kernel/test_kprobes.c
index e78f18144145..a5edc2ebc947 100644
--- a/kernel/test_kprobes.c
+++ b/kernel/test_kprobes.c
@@ -17,6 +17,11 @@ static u32 (*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);
@@ -58,6 +63,33 @@ 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;
@@ -175,12 +207,138 @@ static void test_kretprobes(struct kunit *test)
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;
+ stacktrace_target = kprobe_stacktrace_target;
+ internal_target = kprobe_stacktrace_internal_target;
+ stacktrace_driver = kprobe_stacktrace_driver;
do {
rand1 = prandom_u32();
@@ -194,6 +352,10 @@ static struct kunit_case kprobes_testcases[] = {
#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
{}
};