* [PATCH bpf-next 1/2] selftests/bpf: Add child argument to spawn_child function
2024-08-29 19:45 [PATCH bpf-next 0/2] selftests/bpf: Add uprobe pid filter test Jiri Olsa
@ 2024-08-29 19:45 ` Jiri Olsa
2024-08-29 19:45 ` [PATCH bpf-next 2/2] selftests/bpf: Add uprobe pid filter test for multiple processes Jiri Olsa
2024-08-30 17:08 ` [PATCH bpf-next 0/2] selftests/bpf: Add uprobe pid filter test Stanislav Fomichev
2 siblings, 0 replies; 5+ messages in thread
From: Jiri Olsa @ 2024-08-29 19:45 UTC (permalink / raw)
To: Oleg Nesterov, Peter Zijlstra, Andrii Nakryiko, Tianyi Liu,
Masami Hiramatsu
Cc: bpf, Steven Rostedt, linux-kernel, linux-trace-kernel
Adding child argument to spawn_child function to allow
to create multiple children in following change.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
.../bpf/prog_tests/uprobe_multi_test.c | 85 +++++++++----------
1 file changed, 39 insertions(+), 46 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
index acb62675ff65..250eb47c68f9 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
@@ -68,29 +68,27 @@ static void kick_child(struct child *child)
fflush(NULL);
}
-static struct child *spawn_child(void)
+static int spawn_child(struct child *child)
{
- static struct child child;
- int err;
- int c;
+ int err, c;
/* pipe to notify child to execute the trigger functions */
- if (pipe(child.go))
- return NULL;
+ if (pipe(child->go))
+ return -1;
- child.pid = child.tid = fork();
- if (child.pid < 0) {
- release_child(&child);
+ child->pid = child->tid = fork();
+ if (child->pid < 0) {
+ release_child(child);
errno = EINVAL;
- return NULL;
+ return -1;
}
/* child */
- if (child.pid == 0) {
- close(child.go[1]);
+ if (child->pid == 0) {
+ close(child->go[1]);
/* wait for parent's kick */
- err = read(child.go[0], &c, 1);
+ err = read(child->go[0], &c, 1);
if (err != 1)
exit(err);
@@ -102,7 +100,7 @@ static struct child *spawn_child(void)
exit(errno);
}
- return &child;
+ return 0;
}
static void *child_thread(void *ctx)
@@ -131,39 +129,38 @@ static void *child_thread(void *ctx)
pthread_exit(&err);
}
-static struct child *spawn_thread(void)
+static int spawn_thread(struct child *child)
{
- static struct child child;
int c, err;
/* pipe to notify child to execute the trigger functions */
- if (pipe(child.go))
- return NULL;
+ if (pipe(child->go))
+ return -1;
/* pipe to notify parent that child thread is ready */
- if (pipe(child.c2p)) {
- close(child.go[0]);
- close(child.go[1]);
- return NULL;
+ if (pipe(child->c2p)) {
+ close(child->go[0]);
+ close(child->go[1]);
+ return -1;
}
- child.pid = getpid();
+ child->pid = getpid();
- err = pthread_create(&child.thread, NULL, child_thread, &child);
+ err = pthread_create(&child->thread, NULL, child_thread, child);
if (err) {
err = -errno;
- close(child.go[0]);
- close(child.go[1]);
- close(child.c2p[0]);
- close(child.c2p[1]);
+ close(child->go[0]);
+ close(child->go[1]);
+ close(child->c2p[0]);
+ close(child->c2p[1]);
errno = -err;
- return NULL;
+ return -1;
}
- err = read(child.c2p[0], &c, 1);
+ err = read(child->c2p[0], &c, 1);
if (!ASSERT_EQ(err, 1, "child_thread_ready"))
- return NULL;
+ return -1;
- return &child;
+ return 0;
}
static void uprobe_multi_test_run(struct uprobe_multi *skel, struct child *child)
@@ -304,24 +301,22 @@ __test_attach_api(const char *binary, const char *pattern, struct bpf_uprobe_mul
static void
test_attach_api(const char *binary, const char *pattern, struct bpf_uprobe_multi_opts *opts)
{
- struct child *child;
+ static struct child child;
/* no pid filter */
__test_attach_api(binary, pattern, opts, NULL);
/* pid filter */
- child = spawn_child();
- if (!ASSERT_OK_PTR(child, "spawn_child"))
+ if (!ASSERT_OK(spawn_child(&child), "spawn_child"))
return;
- __test_attach_api(binary, pattern, opts, child);
+ __test_attach_api(binary, pattern, opts, &child);
/* pid filter (thread) */
- child = spawn_thread();
- if (!ASSERT_OK_PTR(child, "spawn_thread"))
+ if (!ASSERT_OK(spawn_thread(&child), "spawn_thread"))
return;
- __test_attach_api(binary, pattern, opts, child);
+ __test_attach_api(binary, pattern, opts, &child);
}
static void test_attach_api_pattern(void)
@@ -712,24 +707,22 @@ static void __test_link_api(struct child *child)
static void test_link_api(void)
{
- struct child *child;
+ static struct child child;
/* no pid filter */
__test_link_api(NULL);
/* pid filter */
- child = spawn_child();
- if (!ASSERT_OK_PTR(child, "spawn_child"))
+ if (!ASSERT_OK(spawn_child(&child), "spawn_child"))
return;
- __test_link_api(child);
+ __test_link_api(&child);
/* pid filter (thread) */
- child = spawn_thread();
- if (!ASSERT_OK_PTR(child, "spawn_thread"))
+ if (!ASSERT_OK(spawn_thread(&child), "spawn_thread"))
return;
- __test_link_api(child);
+ __test_link_api(&child);
}
static struct bpf_program *
--
2.46.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH bpf-next 2/2] selftests/bpf: Add uprobe pid filter test for multiple processes
2024-08-29 19:45 [PATCH bpf-next 0/2] selftests/bpf: Add uprobe pid filter test Jiri Olsa
2024-08-29 19:45 ` [PATCH bpf-next 1/2] selftests/bpf: Add child argument to spawn_child function Jiri Olsa
@ 2024-08-29 19:45 ` Jiri Olsa
2024-08-30 20:51 ` Andrii Nakryiko
2024-08-30 17:08 ` [PATCH bpf-next 0/2] selftests/bpf: Add uprobe pid filter test Stanislav Fomichev
2 siblings, 1 reply; 5+ messages in thread
From: Jiri Olsa @ 2024-08-29 19:45 UTC (permalink / raw)
To: Oleg Nesterov, Peter Zijlstra, Andrii Nakryiko, Tianyi Liu,
Masami Hiramatsu
Cc: bpf, Steven Rostedt, linux-kernel, linux-trace-kernel
The idea is to create and monitor 3 uprobes, each trigered in separate
process and make sure the bpf program gets executed just for the proper
PID specified via pid filter.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
.../bpf/prog_tests/uprobe_multi_test.c | 103 ++++++++++++++++++
.../bpf/progs/uprobe_multi_pid_filter.c | 61 +++++++++++
2 files changed, 164 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/uprobe_multi_pid_filter.c
diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
index 250eb47c68f9..59c460675af9 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
@@ -7,6 +7,7 @@
#include "uprobe_multi_bench.skel.h"
#include "uprobe_multi_usdt.skel.h"
#include "uprobe_multi_consumers.skel.h"
+#include "uprobe_multi_pid_filter.skel.h"
#include "bpf/libbpf_internal.h"
#include "testing_helpers.h"
#include "../sdt.h"
@@ -935,6 +936,106 @@ static void test_consumers(void)
uprobe_multi_consumers__destroy(skel);
}
+typedef struct bpf_link *(create_link_t)(struct uprobe_multi_pid_filter *, int, int, bool);
+
+static struct bpf_program *uprobe_program(struct uprobe_multi_pid_filter *skel, int idx)
+{
+ switch (idx) {
+ case 0: return skel->progs.uprobe_0;
+ case 1: return skel->progs.uprobe_1;
+ case 2: return skel->progs.uprobe_2;
+ }
+ return NULL;
+}
+
+static struct bpf_link *create_link_uprobe(struct uprobe_multi_pid_filter *skel,
+ int idx, int pid, bool retprobe)
+{
+ LIBBPF_OPTS(bpf_uprobe_opts, opts,
+ .retprobe = retprobe,
+ .func_name = "uprobe_multi_func_1",
+ );
+
+ return bpf_program__attach_uprobe_opts(uprobe_program(skel, idx), pid,
+ "/proc/self/exe", 0, &opts);
+}
+
+static struct bpf_program *uprobe_multi_program(struct uprobe_multi_pid_filter *skel, int idx)
+{
+ switch (idx) {
+ case 0: return skel->progs.uprobe_multi_0;
+ case 1: return skel->progs.uprobe_multi_1;
+ case 2: return skel->progs.uprobe_multi_2;
+ }
+ return NULL;
+}
+
+static struct bpf_link *create_link_uprobe_multi(struct uprobe_multi_pid_filter *skel,
+ int idx, int pid, bool retprobe)
+{
+ LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, .retprobe = retprobe);
+
+ return bpf_program__attach_uprobe_multi(uprobe_multi_program(skel, idx), pid,
+ "/proc/self/exe", "uprobe_multi_func_1", &opts);
+}
+
+#define TASKS 3
+
+static void run_pid_filter(struct uprobe_multi_pid_filter *skel,
+ create_link_t create_link, bool retprobe)
+{
+ struct bpf_link *link[TASKS] = {};
+ struct child child[TASKS] = {};
+ int i;
+
+ printf("%s retprobe %d\n", create_link == create_link_uprobe ? "uprobe" : "uprobe_multi",
+ retprobe);
+
+ memset(skel->bss->test, 0, sizeof(skel->bss->test));
+
+ for (i = 0; i < TASKS; i++) {
+ if (!ASSERT_OK(spawn_child(&child[i]), "spawn_child"))
+ goto cleanup;
+ skel->bss->pids[i] = child[i].pid;
+ }
+
+ for (i = 0; i < TASKS; i++) {
+ link[i] = create_link(skel, i, child[i].pid, retprobe);
+ if (!ASSERT_OK_PTR(link[i], "create_link"))
+ goto cleanup;
+ }
+
+ for (i = 0; i < TASKS; i++)
+ kick_child(&child[i]);
+
+ for (i = 0; i < TASKS; i++) {
+ ASSERT_EQ(skel->bss->test[i][0], 1, "pid");
+ ASSERT_EQ(skel->bss->test[i][1], 0, "unknown");
+ }
+
+cleanup:
+ for (i = 0; i < TASKS; i++)
+ bpf_link__destroy(link[i]);
+ for (i = 0; i < TASKS; i++)
+ release_child(&child[i]);
+}
+
+static void test_pid_filter_process(void)
+{
+ struct uprobe_multi_pid_filter *skel;
+
+ skel = uprobe_multi_pid_filter__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "uprobe_multi_pid_filter__open_and_load"))
+ return;
+
+ run_pid_filter(skel, create_link_uprobe, false);
+ run_pid_filter(skel, create_link_uprobe, true);
+ run_pid_filter(skel, create_link_uprobe_multi, false);
+ run_pid_filter(skel, create_link_uprobe_multi, true);
+
+ uprobe_multi_pid_filter__destroy(skel);
+}
+
static void test_bench_attach_uprobe(void)
{
long attach_start_ns = 0, attach_end_ns = 0;
@@ -1027,4 +1128,6 @@ void test_uprobe_multi_test(void)
test_attach_uprobe_fails();
if (test__start_subtest("consumers"))
test_consumers();
+ if (test__start_subtest("filter_process"))
+ test_pid_filter_process();
}
diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi_pid_filter.c b/tools/testing/selftests/bpf/progs/uprobe_multi_pid_filter.c
new file mode 100644
index 000000000000..260d46406e47
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/uprobe_multi_pid_filter.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+char _license[] SEC("license") = "GPL";
+
+__u32 pids[3];
+__u32 test[3][2];
+
+static void update_pid(int idx)
+{
+ __u32 pid = bpf_get_current_pid_tgid() >> 32;
+
+ if (pid == pids[idx])
+ test[idx][0]++;
+ else
+ test[idx][1]++;
+}
+
+SEC("uprobe.multi")
+int uprobe_multi_0(struct pt_regs *ctx)
+{
+ update_pid(0);
+ return 0;
+}
+
+SEC("uprobe.multi")
+int uprobe_multi_1(struct pt_regs *ctx)
+{
+ update_pid(1);
+ return 0;
+}
+
+SEC("uprobe.multi")
+int uprobe_multi_2(struct pt_regs *ctx)
+{
+ update_pid(2);
+ return 0;
+}
+
+SEC("uprobe")
+int uprobe_0(struct pt_regs *ctx)
+{
+ update_pid(0);
+ return 0;
+}
+
+SEC("uprobe")
+int uprobe_1(struct pt_regs *ctx)
+{
+ update_pid(1);
+ return 0;
+}
+
+SEC("uprobe")
+int uprobe_2(struct pt_regs *ctx)
+{
+ update_pid(2);
+ return 0;
+}
--
2.46.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH bpf-next 2/2] selftests/bpf: Add uprobe pid filter test for multiple processes
2024-08-29 19:45 ` [PATCH bpf-next 2/2] selftests/bpf: Add uprobe pid filter test for multiple processes Jiri Olsa
@ 2024-08-30 20:51 ` Andrii Nakryiko
0 siblings, 0 replies; 5+ messages in thread
From: Andrii Nakryiko @ 2024-08-30 20:51 UTC (permalink / raw)
To: Jiri Olsa
Cc: Oleg Nesterov, Peter Zijlstra, Andrii Nakryiko, Tianyi Liu,
Masami Hiramatsu, bpf, Steven Rostedt, linux-kernel,
linux-trace-kernel
On Thu, Aug 29, 2024 at 12:45 PM Jiri Olsa <jolsa@kernel.org> wrote:
>
> The idea is to create and monitor 3 uprobes, each trigered in separate
typo: triggered
> process and make sure the bpf program gets executed just for the proper
> PID specified via pid filter.
>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
> .../bpf/prog_tests/uprobe_multi_test.c | 103 ++++++++++++++++++
> .../bpf/progs/uprobe_multi_pid_filter.c | 61 +++++++++++
> 2 files changed, 164 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/progs/uprobe_multi_pid_filter.c
>
It's good to have a test, thanks for adding it! But we should couple
it with the fix in multi-uprobe and land together, right? I'm not
exactly sure why we can't just use task->signal-based check, but let's
try to converge on something and fix it.
pw-bot: cr
[...]
> +#define TASKS 3
> +
> +static void run_pid_filter(struct uprobe_multi_pid_filter *skel,
> + create_link_t create_link, bool retprobe)
> +{
> + struct bpf_link *link[TASKS] = {};
> + struct child child[TASKS] = {};
> + int i;
> +
> + printf("%s retprobe %d\n", create_link == create_link_uprobe ? "uprobe" : "uprobe_multi",
> + retprobe);
leftovers
> +
> + memset(skel->bss->test, 0, sizeof(skel->bss->test));
> +
> + for (i = 0; i < TASKS; i++) {
> + if (!ASSERT_OK(spawn_child(&child[i]), "spawn_child"))
> + goto cleanup;
> + skel->bss->pids[i] = child[i].pid;
> + }
[...]
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH bpf-next 0/2] selftests/bpf: Add uprobe pid filter test
2024-08-29 19:45 [PATCH bpf-next 0/2] selftests/bpf: Add uprobe pid filter test Jiri Olsa
2024-08-29 19:45 ` [PATCH bpf-next 1/2] selftests/bpf: Add child argument to spawn_child function Jiri Olsa
2024-08-29 19:45 ` [PATCH bpf-next 2/2] selftests/bpf: Add uprobe pid filter test for multiple processes Jiri Olsa
@ 2024-08-30 17:08 ` Stanislav Fomichev
2 siblings, 0 replies; 5+ messages in thread
From: Stanislav Fomichev @ 2024-08-30 17:08 UTC (permalink / raw)
To: Jiri Olsa
Cc: Oleg Nesterov, Peter Zijlstra, Andrii Nakryiko, Tianyi Liu,
Masami Hiramatsu, bpf, Steven Rostedt, linux-kernel,
linux-trace-kernel
On 08/29, Jiri Olsa wrote:
> hi,
> in response to [1] patch, I'm adding bpf selftest that confirms the
> change fixes problem for bpf programs trigered by return uprobe created
> over perf event.
>
> Oleg pointed out other issues with uprobe_multi pid filter,
> I plan to send another patchset for that.
Not sure whether Oleg or Andrii plan to take a look, but LGTM:
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
^ permalink raw reply [flat|nested] 5+ messages in thread