1 files changed, 195 insertions, 79 deletions

diff --git a/arch/s390/lib/test_unwind.c b/arch/s390/lib/test_unwind.c
index bc7973359ae2..c01f02887de4 100644
--- a/arch/s390/lib/test_unwind.c
+++ b/arch/s390/lib/test_unwind.c
@@ -8,6 +8,7 @@
 #include <linux/completion.h>
 #include <linux/kallsyms.h>
 #include <linux/kthread.h>
+#include <linux/ftrace.h>
 #include <linux/module.h>
 #include <linux/timer.h>
 #include <linux/slab.h>
@@ -16,10 +17,14 @@
 #include <linux/wait.h>
 #include <asm/irq.h>
 
-struct kunit *current_test;
+static struct kunit *current_test;
 
 #define BT_BUF_SIZE (PAGE_SIZE * 4)
 
+static bool force_bt;
+module_param_named(backtrace, force_bt, bool, 0444);
+MODULE_PARM_DESC(backtrace, "print backtraces for all tests");
+
 /*
  * To avoid printk line limit split backtrace by lines
  */
@@ -98,7 +103,7 @@ static noinline int test_unwind(struct task_struct *task, struct pt_regs *regs,
 		kunit_err(current_test, "Maximum number of frames exceeded\n");
 		ret = -EINVAL;
 	}
-	if (ret)
+	if (ret || force_bt)
 		print_backtrace(bt);
 	kfree(bt);
 	return ret;
@@ -124,7 +129,10 @@ static struct unwindme *unwindme;
 #define UWM_CALLER		0x8	/* Unwind starting from caller. */
 #define UWM_SWITCH_STACK	0x10	/* Use call_on_stack. */
 #define UWM_IRQ			0x20	/* Unwind from irq context. */
-#define UWM_PGM			0x40	/* Unwind from program check handler. */
+#define UWM_PGM			0x40	/* Unwind from program check handler */
+#define UWM_KPROBE_ON_FTRACE	0x80	/* Unwind from kprobe handler called via ftrace. */
+#define UWM_FTRACE		0x100	/* Unwind from ftrace handler. */
+#define UWM_KRETPROBE		0x200	/* Unwind kretprobe handlers. */
 
 static __always_inline unsigned long get_psw_addr(void)
 {
@@ -136,8 +144,56 @@ static __always_inline unsigned long get_psw_addr(void)
 	return psw_addr;
 }
 
-#ifdef CONFIG_KPROBES
-static int pgm_pre_handler(struct kprobe *p, struct pt_regs *regs)
+static int kretprobe_ret_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+	struct unwindme *u = unwindme;
+
+	u->ret = test_unwind(NULL, (u->flags & UWM_REGS) ? regs : NULL,
+			     (u->flags & UWM_SP) ? u->sp : 0);
+
+	return 0;
+}
+
+static noinline notrace void test_unwind_kretprobed_func(void)
+{
+	asm volatile("	nop\n");
+}
+
+static noinline void test_unwind_kretprobed_func_caller(void)
+{
+	test_unwind_kretprobed_func();
+}
+
+static int test_unwind_kretprobe(struct unwindme *u)
+{
+	int ret;
+	struct kretprobe my_kretprobe;
+
+	if (!IS_ENABLED(CONFIG_KPROBES))
+		kunit_skip(current_test, "requires CONFIG_KPROBES");
+
+	u->ret = -1; /* make sure kprobe is called */
+	unwindme = u;
+
+	memset(&my_kretprobe, 0, sizeof(my_kretprobe));
+	my_kretprobe.handler = kretprobe_ret_handler;
+	my_kretprobe.maxactive = 1;
+	my_kretprobe.kp.addr = (kprobe_opcode_t *)test_unwind_kretprobed_func;
+
+	ret = register_kretprobe(&my_kretprobe);
+
+	if (ret < 0) {
+		kunit_err(current_test, "register_kretprobe failed %d\n", ret);
+		return -EINVAL;
+	}
+
+	test_unwind_kretprobed_func_caller();
+	unregister_kretprobe(&my_kretprobe);
+	unwindme = NULL;
+	return u->ret;
+}
+
+static int kprobe_pre_handler(struct kprobe *p, struct pt_regs *regs)
 {
 	struct unwindme *u = unwindme;
 
@@ -145,8 +201,97 @@ static int pgm_pre_handler(struct kprobe *p, struct pt_regs *regs)
 			     (u->flags & UWM_SP) ? u->sp : 0);
 	return 0;
 }
+
+extern const char test_unwind_kprobed_insn[];
+
+static noinline void test_unwind_kprobed_func(void)
+{
+	asm volatile(
+		"	nopr	%%r7\n"
+		"test_unwind_kprobed_insn:\n"
+		"	nopr	%%r7\n"
+		:);
+}
+
+static int test_unwind_kprobe(struct unwindme *u)
+{
+	struct kprobe kp;
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_KPROBES))
+		kunit_skip(current_test, "requires CONFIG_KPROBES");
+	if (!IS_ENABLED(CONFIG_KPROBES_ON_FTRACE) && u->flags & UWM_KPROBE_ON_FTRACE)
+		kunit_skip(current_test, "requires CONFIG_KPROBES_ON_FTRACE");
+
+	u->ret = -1; /* make sure kprobe is called */
+	unwindme = u;
+	memset(&kp, 0, sizeof(kp));
+	kp.pre_handler = kprobe_pre_handler;
+	kp.addr = u->flags & UWM_KPROBE_ON_FTRACE ?
+				(kprobe_opcode_t *)test_unwind_kprobed_func :
+				(kprobe_opcode_t *)test_unwind_kprobed_insn;
+	ret = register_kprobe(&kp);
+	if (ret < 0) {
+		kunit_err(current_test, "register_kprobe failed %d\n", ret);
+		return -EINVAL;
+	}
+
+	test_unwind_kprobed_func();
+	unregister_kprobe(&kp);
+	unwindme = NULL;
+	return u->ret;
+}
+
+static void notrace __used test_unwind_ftrace_handler(unsigned long ip,
+						      unsigned long parent_ip,
+						      struct ftrace_ops *fops,
+						      struct ftrace_regs *fregs)
+{
+	struct unwindme *u = (struct unwindme *)fregs->regs.gprs[2];
+
+	u->ret = test_unwind(NULL, (u->flags & UWM_REGS) ? &fregs->regs : NULL,
+			     (u->flags & UWM_SP) ? u->sp : 0);
+}
+
+static noinline int test_unwind_ftraced_func(struct unwindme *u)
+{
+	return READ_ONCE(u)->ret;
+}
+
+static int test_unwind_ftrace(struct unwindme *u)
+{
+	int ret;
+#ifdef CONFIG_DYNAMIC_FTRACE
+	struct ftrace_ops *fops;
+
+	fops = kunit_kzalloc(current_test, sizeof(*fops), GFP_KERNEL);
+	fops->func = test_unwind_ftrace_handler;
+	fops->flags = FTRACE_OPS_FL_DYNAMIC |
+		     FTRACE_OPS_FL_RECURSION |
+		     FTRACE_OPS_FL_SAVE_REGS |
+		     FTRACE_OPS_FL_PERMANENT;
+#else
+	kunit_skip(current_test, "requires CONFIG_DYNAMIC_FTRACE");
 #endif
 
+	ret = ftrace_set_filter_ip(fops, (unsigned long)test_unwind_ftraced_func, 0, 0);
+	if (ret) {
+		kunit_err(current_test, "failed to set ftrace filter (%d)\n", ret);
+		return -1;
+	}
+
+	ret = register_ftrace_function(fops);
+	if (!ret) {
+		ret = test_unwind_ftraced_func(u);
+		unregister_ftrace_function(fops);
+	} else {
+		kunit_err(current_test, "failed to register ftrace handler (%d)\n", ret);
+	}
+
+	ftrace_set_filter_ip(fops, (unsigned long)test_unwind_ftraced_func, 1, 0);
+	return ret;
+}
+
 /* This function may or may not appear in the backtrace. */
 static noinline int unwindme_func4(struct unwindme *u)
 {
@@ -157,35 +302,12 @@ static noinline int unwindme_func4(struct unwindme *u)
 		wait_event(u->task_wq, kthread_should_park());
 		kthread_parkme();
 		return 0;
-#ifdef CONFIG_KPROBES
-	} else if (u->flags & UWM_PGM) {
-		struct kprobe kp;
-		int ret;
-
-		unwindme = u;
-		memset(&kp, 0, sizeof(kp));
-		kp.symbol_name = "do_report_trap";
-		kp.pre_handler = pgm_pre_handler;
-		ret = register_kprobe(&kp);
-		if (ret < 0) {
-			kunit_err(current_test, "register_kprobe failed %d\n", ret);
-			return -EINVAL;
-		}
-
-		/*
-		 * Trigger operation exception; use insn notation to bypass
-		 * llvm's integrated assembler sanity checks.
-		 */
-		asm volatile(
-			"	.insn	e,0x0000\n"	/* illegal opcode */
-			"0:	nopr	%%r7\n"
-			EX_TABLE(0b, 0b)
-			:);
-
-		unregister_kprobe(&kp);
-		unwindme = NULL;
-		return u->ret;
-#endif
+	} else if (u->flags & (UWM_PGM | UWM_KPROBE_ON_FTRACE)) {
+		return test_unwind_kprobe(u);
+	} else if (u->flags & (UWM_KRETPROBE)) {
+		return test_unwind_kretprobe(u);
+	} else if (u->flags & UWM_FTRACE) {
+		return test_unwind_ftrace(u);
 	} else {
 		struct pt_regs regs;
 
@@ -255,7 +377,7 @@ static int test_unwind_irq(struct unwindme *u)
 }
 
 /* Spawns a task and passes it to test_unwind(). */
-static int test_unwind_task(struct kunit *test, struct unwindme *u)
+static int test_unwind_task(struct unwindme *u)
 {
 	struct task_struct *task;
 	int ret;
@@ -270,7 +392,7 @@ static int test_unwind_task(struct kunit *test, struct unwindme *u)
 	 */
 	task = kthread_run(unwindme_func1, u, "%s", __func__);
 	if (IS_ERR(task)) {
-		kunit_err(test, "kthread_run() failed\n");
+		kunit_err(current_test, "kthread_run() failed\n");
 		return PTR_ERR(task);
 	}
 	/*
@@ -293,49 +415,43 @@ struct test_params {
 /*
  * Create required parameter list for tests
  */
+#define TEST_WITH_FLAGS(f) { .flags = f, .name = #f }
 static const struct test_params param_list[] = {
-	{.flags = UWM_DEFAULT, .name = "UWM_DEFAULT"},
-	{.flags = UWM_SP, .name = "UWM_SP"},
-	{.flags = UWM_REGS, .name = "UWM_REGS"},
-	{.flags = UWM_SWITCH_STACK,
-		.name = "UWM_SWITCH_STACK"},
-	{.flags = UWM_SP | UWM_REGS,
-		.name = "UWM_SP | UWM_REGS"},
-	{.flags = UWM_CALLER | UWM_SP,
-		.name = "WM_CALLER | UWM_SP"},
-	{.flags = UWM_CALLER | UWM_SP | UWM_REGS,
-		.name = "UWM_CALLER | UWM_SP | UWM_REGS"},
-	{.flags = UWM_CALLER | UWM_SP | UWM_REGS | UWM_SWITCH_STACK,
-		.name = "UWM_CALLER | UWM_SP | UWM_REGS | UWM_SWITCH_STACK"},
-	{.flags = UWM_THREAD, .name = "UWM_THREAD"},
-	{.flags = UWM_THREAD | UWM_SP,
-		.name = "UWM_THREAD | UWM_SP"},
-	{.flags = UWM_THREAD | UWM_CALLER | UWM_SP,
-		.name = "UWM_THREAD | UWM_CALLER | UWM_SP"},
-	{.flags = UWM_IRQ, .name = "UWM_IRQ"},
-	{.flags = UWM_IRQ | UWM_SWITCH_STACK,
-		.name = "UWM_IRQ | UWM_SWITCH_STACK"},
-	{.flags = UWM_IRQ | UWM_SP,
-		.name = "UWM_IRQ | UWM_SP"},
-	{.flags = UWM_IRQ | UWM_REGS,
-		.name = "UWM_IRQ | UWM_REGS"},
-	{.flags = UWM_IRQ | UWM_SP | UWM_REGS,
-		.name = "UWM_IRQ | UWM_SP | UWM_REGS"},
-	{.flags = UWM_IRQ | UWM_CALLER | UWM_SP,
-		.name = "UWM_IRQ | UWM_CALLER | UWM_SP"},
-	{.flags = UWM_IRQ | UWM_CALLER | UWM_SP | UWM_REGS,
-		.name = "UWM_IRQ | UWM_CALLER | UWM_SP | UWM_REGS"},
-	{.flags = UWM_IRQ | UWM_CALLER | UWM_SP | UWM_REGS | UWM_SWITCH_STACK,
-		.name = "UWM_IRQ | UWM_CALLER | UWM_SP | UWM_REGS | UWM_SWITCH_STACK"},
-	#ifdef CONFIG_KPROBES
-	{.flags = UWM_PGM, .name = "UWM_PGM"},
-	{.flags = UWM_PGM | UWM_SP,
-		.name = "UWM_PGM | UWM_SP"},
-	{.flags = UWM_PGM | UWM_REGS,
-		.name = "UWM_PGM | UWM_REGS"},
-	{.flags = UWM_PGM | UWM_SP | UWM_REGS,
-		.name = "UWM_PGM | UWM_SP | UWM_REGS"},
-	#endif
+	TEST_WITH_FLAGS(UWM_DEFAULT),
+	TEST_WITH_FLAGS(UWM_SP),
+	TEST_WITH_FLAGS(UWM_REGS),
+	TEST_WITH_FLAGS(UWM_SWITCH_STACK),
+	TEST_WITH_FLAGS(UWM_SP | UWM_REGS),
+	TEST_WITH_FLAGS(UWM_CALLER | UWM_SP),
+	TEST_WITH_FLAGS(UWM_CALLER | UWM_SP | UWM_REGS),
+	TEST_WITH_FLAGS(UWM_CALLER | UWM_SP | UWM_REGS | UWM_SWITCH_STACK),
+	TEST_WITH_FLAGS(UWM_THREAD),
+	TEST_WITH_FLAGS(UWM_THREAD | UWM_SP),
+	TEST_WITH_FLAGS(UWM_THREAD | UWM_CALLER | UWM_SP),
+	TEST_WITH_FLAGS(UWM_IRQ),
+	TEST_WITH_FLAGS(UWM_IRQ | UWM_SWITCH_STACK),
+	TEST_WITH_FLAGS(UWM_IRQ | UWM_SP),
+	TEST_WITH_FLAGS(UWM_IRQ | UWM_REGS),
+	TEST_WITH_FLAGS(UWM_IRQ | UWM_SP | UWM_REGS),
+	TEST_WITH_FLAGS(UWM_IRQ | UWM_CALLER | UWM_SP),
+	TEST_WITH_FLAGS(UWM_IRQ | UWM_CALLER | UWM_SP | UWM_REGS),
+	TEST_WITH_FLAGS(UWM_IRQ | UWM_CALLER | UWM_SP | UWM_REGS | UWM_SWITCH_STACK),
+	TEST_WITH_FLAGS(UWM_PGM),
+	TEST_WITH_FLAGS(UWM_PGM | UWM_SP),
+	TEST_WITH_FLAGS(UWM_PGM | UWM_REGS),
+	TEST_WITH_FLAGS(UWM_PGM | UWM_SP | UWM_REGS),
+	TEST_WITH_FLAGS(UWM_KPROBE_ON_FTRACE),
+	TEST_WITH_FLAGS(UWM_KPROBE_ON_FTRACE | UWM_SP),
+	TEST_WITH_FLAGS(UWM_KPROBE_ON_FTRACE | UWM_REGS),
+	TEST_WITH_FLAGS(UWM_KPROBE_ON_FTRACE | UWM_SP | UWM_REGS),
+	TEST_WITH_FLAGS(UWM_FTRACE),
+	TEST_WITH_FLAGS(UWM_FTRACE | UWM_SP),
+	TEST_WITH_FLAGS(UWM_FTRACE | UWM_REGS),
+	TEST_WITH_FLAGS(UWM_FTRACE | UWM_SP | UWM_REGS),
+	TEST_WITH_FLAGS(UWM_KRETPROBE),
+	TEST_WITH_FLAGS(UWM_KRETPROBE | UWM_SP),
+	TEST_WITH_FLAGS(UWM_KRETPROBE | UWM_REGS),
+	TEST_WITH_FLAGS(UWM_KRETPROBE | UWM_SP | UWM_REGS),
 };
 
 /*
@@ -360,7 +476,7 @@ static void test_unwind_flags(struct kunit *test)
 	params = (const struct test_params *)test->param_value;
 	u.flags = params->flags;
 	if (u.flags & UWM_THREAD)
-		KUNIT_EXPECT_EQ(test, 0, test_unwind_task(test, &u));
+		KUNIT_EXPECT_EQ(test, 0, test_unwind_task(&u));
 	else if (u.flags & UWM_IRQ)
 		KUNIT_EXPECT_EQ(test, 0, test_unwind_irq(&u));
 	else