linux-kernel - Re: [PATCH bpf-next v3 2/2] selftests/bpf: Add stacktrace map lookup_and_delete

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <f1d2d0fc-c541-4acc-b5d6-34f2bba37aea@gmail.com>
Date: Mon, 22 Sep 2025 10:42:44 +0800
From: Leon Hwang <hffilwlqm@...il.com>
To: Tao Chen <chen.dylane@...ux.dev>, ast@...nel.org, daniel@...earbox.net,
 john.fastabend@...il.com, andrii@...nel.org, martin.lau@...ux.dev,
 eddyz87@...il.com, song@...nel.org, yonghong.song@...ux.dev,
 kpsingh@...nel.org, sdf@...ichev.me, haoluo@...gle.com, jolsa@...nel.org
Cc: bpf@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH bpf-next v3 2/2] selftests/bpf: Add stacktrace map
 lookup_and_delete_elem test case



On 20/9/25 23:52, Tao Chen wrote:
> ...
> test_stacktrace_map:PASS:compare_stack_ips stackmap vs. stack_amap 0 nsec
> test_stacktrace_map:PASS:stack_key_map lookup 0 nsec
> test_stacktrace_map:PASS:stackmap lookup and detele 0 nsec
> test_stacktrace_map:PASS:stackmap lookup deleted stack_id 0 nsec
>  #397     stacktrace_map:OK
> ...

As they suppose to pass, they are meaningless in the commit log.

Please describe what the test is for and what it is doing instead.

> 
> Signed-off-by: Tao Chen <chen.dylane@...ux.dev>
> ---
>  .../selftests/bpf/prog_tests/stacktrace_map.c | 22 ++++++++++++++++++-
>  .../selftests/bpf/progs/test_stacktrace_map.c |  8 +++++++
>  2 files changed, 29 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/bpf/prog_tests/stacktrace_map.c b/tools/testing/selftests/bpf/prog_tests/stacktrace_map.c
> index 84a7e405e91..7d38afe5cfc 100644
> --- a/tools/testing/selftests/bpf/prog_tests/stacktrace_map.c
> +++ b/tools/testing/selftests/bpf/prog_tests/stacktrace_map.c
> @@ -3,7 +3,7 @@
>  
>  void test_stacktrace_map(void)
>  {
> -	int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd;
> +	int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd, stack_key_map_fd;
>  	const char *prog_name = "oncpu";
>  	int err, prog_fd, stack_trace_len;
>  	const char *file = "./test_stacktrace_map.bpf.o";
> @@ -11,6 +11,9 @@ void test_stacktrace_map(void)
>  	struct bpf_program *prog;
>  	struct bpf_object *obj;
>  	struct bpf_link *link;
> +	__u32 stack_id;
> +	char val_buf[PERF_MAX_STACK_DEPTH *
> +		sizeof(struct bpf_stack_build_id)];

Nit: minor indentation issue here.

'val_buf' should stay on a single line, since up to 100 characters per
line are allowed.

NOTE: keep inverted Christmas tree style.

Thanks,
Leon

>  
>  	err = bpf_prog_test_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
>  	if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno))
> @@ -41,6 +44,10 @@ void test_stacktrace_map(void)
>  	if (CHECK_FAIL(stack_amap_fd < 0))
>  		goto disable_pmu;
>  
> +	stack_key_map_fd = bpf_find_map(__func__, obj, "stack_key_map");
> +	if (CHECK_FAIL(stack_key_map_fd < 0))
> +		goto disable_pmu;
> +
>  	/* give some time for bpf program run */
>  	sleep(1);
>  

[...]