When I use bpf_program__attach_kprobe_multi_opts to hook a BPF program that
contains the bpf_get_stackid function on the arm64 architecture,
I find that the stack trace cannot be obtained. The trace->nr in
__bpf_get_stackid is 0, and the function returns -EFAULT.
For example:
diff --git a/tools/testing/selftests/bpf/progs/kprobe_multi.c
b/tools/testing/selftests/bpf/progs/kprobe_multi.c
index 9e1ca8e34913..844fa88cdc4c 100644
--- a/tools/testing/selftests/bpf/progs/kprobe_multi.c
+++ b/tools/testing/selftests/bpf/progs/kprobe_multi.c
@@ -36,6 +36,15 @@ __u64 kretprobe_test6_result = 0;
__u64 kretprobe_test7_result = 0;
__u64 kretprobe_test8_result = 0;
+typedef __u64 stack_trace_t[2];
+
+struct {
+ __uint(type, BPF_MAP_TYPE_STACK_TRACE);
+ __uint(max_entries, 1024);
+ __type(key, __u32);
+ __type(value, stack_trace_t);
+} stacks SEC(".maps");
+
static void kprobe_multi_check(void *ctx, bool is_return)
{
if (bpf_get_current_pid_tgid() >> 32 != pid)
@@ -100,7 +109,9 @@ int test_kretprobe(struct pt_regs *ctx)
SEC("kprobe.multi")
int test_kprobe_manual(struct pt_regs *ctx)
{
+ int id = bpf_get_stackid(ctx, &stacks, 0);
kprobe_multi_check(ctx, false);
+ bpf_printk("stackid: %d\n", id);
return 0;
}
./test_progs -t kprobe_multi_test/attach_api_pattern
#155/4 kprobe_multi_test/attach_api_pattern:OK
#155 kprobe_multi_test:OK
#156 kprobe_multi_testmod_test:OK
Summary: 2/1 PASSED, 0 SKIPPED, 0 FAILED
cat /sys/kernel/debug/tracing/trace
test_progs-68315 [004] ...1. 13377.097527: bpf_trace_printk: stackid: -14
......
Test Version:
6ff4a0fa3e1 ("bpf, arm64: Call bpf_jit_binary_pack_finalize() in
bpf_jit_free()")
Linux localhost.localdomain 6.17.0-rc5+ #2 SMP PREEMPT_DYNAMIC Fri Sep 19
10:29:07 CST 2025 aarch64 aarch64 aarch64 GNU/Linux
clang version 17.0.6 ( 17.0.6-30.p03.ky11)
gcc (GCC) 12.3.1 (kylin 12.3.1-62.p02.ky11)
GNU Make 4.4.1
