Commit c65f677b authored by Tobias Huschle's avatar Tobias Huschle Committed by Vasily Gorbik
Browse files

s390/test_unwind: add kretprobe tests 



Add tests to verify that s390 kretprobes maintain a correct stack
chain and ensure their proper function.

Reviewed-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarTobias Huschle <huschle@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 63bf38ff

arch/s390/lib/test_unwind.c

+56 −0
Original line number Diff line number Diff line
@@ -132,6 +132,7 @@ static struct unwindme *unwindme; 
#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)

{
@@ -143,6 +144,55 @@ static __always_inline unsigned long get_psw_addr(void) 
	return psw_addr;

}



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;
@@ -254,6 +304,8 @@ static noinline int unwindme_func4(struct unwindme *u) 
		return 0;

	} 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 {
@@ -396,6 +448,10 @@ static const struct test_params param_list[] = { 
	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),

};



/*