1 files changed, 119 insertions, 4 deletions

diff --git a/tools/testing/selftests/bpf/progs/bpf_loop.c b/tools/testing/selftests/bpf/progs/bpf_loop.c
index 12349e4601e8..de1fc82d2710 100644
--- a/tools/testing/selftests/bpf/progs/bpf_loop.c
+++ b/tools/testing/selftests/bpf/progs/bpf_loop.c
@@ -3,6 +3,7 @@
 
 #include "vmlinux.h"
 #include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
 
 char _license[] SEC("license") = "GPL";
 
@@ -10,11 +11,19 @@ struct callback_ctx {
 	int output;
 };
 
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 32);
+	__type(key, int);
+	__type(value, int);
+} map1 SEC(".maps");
+
 /* These should be set by the user program */
 u32 nested_callback_nr_loops;
 u32 stop_index = -1;
 u32 nr_loops;
 int pid;
+int callback_selector;
 
 /* Making these global variables so that the userspace program
  * can verify the output through the skeleton
@@ -53,7 +62,7 @@ static int nested_callback1(__u32 index, void *data)
 	return 0;
 }
 
-SEC("fentry/__x64_sys_nanosleep")
+SEC("fentry/" SYS_PREFIX "sys_nanosleep")
 int test_prog(void *ctx)
 {
 	struct callback_ctx data = {};
@@ -71,7 +80,7 @@ int test_prog(void *ctx)
 	return 0;
 }
 
-SEC("fentry/__x64_sys_nanosleep")
+SEC("fentry/" SYS_PREFIX "sys_nanosleep")
 int prog_null_ctx(void *ctx)
 {
 	if (bpf_get_current_pid_tgid() >> 32 != pid)
@@ -82,7 +91,7 @@ int prog_null_ctx(void *ctx)
 	return 0;
 }
 
-SEC("fentry/__x64_sys_nanosleep")
+SEC("fentry/" SYS_PREFIX "sys_nanosleep")
 int prog_invalid_flags(void *ctx)
 {
 	struct callback_ctx data = {};
@@ -95,7 +104,7 @@ int prog_invalid_flags(void *ctx)
 	return 0;
 }
 
-SEC("fentry/__x64_sys_nanosleep")
+SEC("fentry/" SYS_PREFIX "sys_nanosleep")
 int prog_nested_calls(void *ctx)
 {
 	struct callback_ctx data = {};
@@ -110,3 +119,109 @@ int prog_nested_calls(void *ctx)
 
 	return 0;
 }
+
+static int callback_set_f0(int i, void *ctx)
+{
+	g_output = 0xF0;
+	return 0;
+}
+
+static int callback_set_0f(int i, void *ctx)
+{
+	g_output = 0x0F;
+	return 0;
+}
+
+/*
+ * non-constant callback is a corner case for bpf_loop inline logic
+ */
+SEC("fentry/" SYS_PREFIX "sys_nanosleep")
+int prog_non_constant_callback(void *ctx)
+{
+	struct callback_ctx data = {};
+
+	if (bpf_get_current_pid_tgid() >> 32 != pid)
+		return 0;
+
+	int (*callback)(int i, void *ctx);
+
+	g_output = 0;
+
+	if (callback_selector == 0x0F)
+		callback = callback_set_0f;
+	else
+		callback = callback_set_f0;
+
+	bpf_loop(1, callback, NULL, 0);
+
+	return 0;
+}
+
+static int stack_check_inner_callback(void *ctx)
+{
+	return 0;
+}
+
+static int map1_lookup_elem(int key)
+{
+	int *val = bpf_map_lookup_elem(&map1, &key);
+
+	return val ? *val : -1;
+}
+
+static void map1_update_elem(int key, int val)
+{
+	bpf_map_update_elem(&map1, &key, &val, BPF_ANY);
+}
+
+static int stack_check_outer_callback(void *ctx)
+{
+	int a = map1_lookup_elem(1);
+	int b = map1_lookup_elem(2);
+	int c = map1_lookup_elem(3);
+	int d = map1_lookup_elem(4);
+	int e = map1_lookup_elem(5);
+	int f = map1_lookup_elem(6);
+
+	bpf_loop(1, stack_check_inner_callback, NULL, 0);
+
+	map1_update_elem(1, a + 1);
+	map1_update_elem(2, b + 1);
+	map1_update_elem(3, c + 1);
+	map1_update_elem(4, d + 1);
+	map1_update_elem(5, e + 1);
+	map1_update_elem(6, f + 1);
+
+	return 0;
+}
+
+/* Some of the local variables in stack_check and
+ * stack_check_outer_callback would be allocated on stack by
+ * compiler. This test should verify that stack content for these
+ * variables is preserved between calls to bpf_loop (might be an issue
+ * if loop inlining allocates stack slots incorrectly).
+ */
+SEC("fentry/" SYS_PREFIX "sys_nanosleep")
+int stack_check(void *ctx)
+{
+	if (bpf_get_current_pid_tgid() >> 32 != pid)
+		return 0;
+
+	int a = map1_lookup_elem(7);
+	int b = map1_lookup_elem(8);
+	int c = map1_lookup_elem(9);
+	int d = map1_lookup_elem(10);
+	int e = map1_lookup_elem(11);
+	int f = map1_lookup_elem(12);
+
+	bpf_loop(1, stack_check_outer_callback, NULL, 0);
+
+	map1_update_elem(7,  a + 1);
+	map1_update_elem(8, b + 1);
+	map1_update_elem(9, c + 1);
+	map1_update_elem(10, d + 1);
+	map1_update_elem(11, e + 1);
+	map1_update_elem(12, f + 1);
+
+	return 0;
+}