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: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
diff --git a/arch/s390/lib/test_unwind.c b/arch/s390/lib/test_unwind.c
index 07ef89e..c01f028 100644
--- a/arch/s390/lib/test_unwind.c
+++ b/arch/s390/lib/test_unwind.c
@@ -132,6 +132,7 @@
#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 @@
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 @@
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 @@
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),
};
/*
