Thread (16 messages) 16 messages, 4 authors, 2022-03-01

Re: [PATCH v3 bpf-next 4/4] selftests/bpf: add tests for u[ret]probe attach by name

From: Andrii Nakryiko <hidden>
Date: 2022-02-04 19:30:30
Also in: bpf

On Mon, Jan 31, 2022 at 8:13 AM Alan Maguire [off-list ref] wrote:
add tests that verify attaching by name for

1. local functions in a program
2. library functions in a shared object; and
3. library functions in a program

...succeed for uprobe and uretprobes using new "func_name"
option for bpf_program__attach_uprobe_opts().  Also verify
auto-attach works where uprobe, path to binary and function
name are specified, but fails with -ESRCH when the format
does not match (the latter is to support backwards-compatibility).

Signed-off-by: Alan Maguire <redacted>
---
 .../selftests/bpf/prog_tests/attach_probe.c        | 89 +++++++++++++++++++++-
 .../selftests/bpf/progs/test_attach_probe.c        | 37 +++++++++
 2 files changed, 123 insertions(+), 3 deletions(-)
[...]
quoted hunk ↗ jump to hunk
        if (CHECK(skel->bss->uprobe_res != 3, "check_uprobe_res",
                  "wrong uprobe res: %d\n", skel->bss->uprobe_res))
                goto cleanup;
@@ -110,7 +179,21 @@ void test_attach_probe(void)
                  "wrong uretprobe res: %d\n", skel->bss->uretprobe_res))
                goto cleanup;

+       if (CHECK(skel->bss->uprobe_byname_res != 5, "check_uprobe_byname_res",
+                 "wrong uprobe byname res: %d\n", skel->bss->uprobe_byname_res))
+               goto cleanup;
+       if (CHECK(skel->bss->uretprobe_byname_res != 6, "check_uretprobe_byname_res",
+                 "wrong uretprobe byname res: %d\n", skel->bss->uretprobe_byname_res))
+               goto cleanup;
+       if (CHECK(skel->bss->uprobe_byname2_res != 7, "check_uprobe_byname2_res",
+                 "wrong uprobe byname2 res: %d\n", skel->bss->uprobe_byname2_res))
+               goto cleanup;
+       if (CHECK(skel->bss->uretprobe_byname2_res != 8, "check_uretprobe_byname2_res",
+                 "wrong uretprobe byname2 res: %d\n", skel->bss->uretprobe_byname2_res))
+               goto cleanup;
+
Please don't use CHECK()s for new code, only ASSERT_xxx() for new code.
quoted hunk ↗ jump to hunk
 cleanup:
+       free(libc_path);
        test_attach_probe__destroy(skel);
        ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup");
 }
diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c
index 8056a4c..9942461c 100644
--- a/tools/testing/selftests/bpf/progs/test_attach_probe.c
+++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c
@@ -10,6 +10,10 @@
 int kretprobe_res = 0;
 int uprobe_res = 0;
 int uretprobe_res = 0;
+int uprobe_byname_res = 0;
+int uretprobe_byname_res = 0;
+int uprobe_byname2_res = 0;
+int uretprobe_byname2_res = 0;

 SEC("kprobe/sys_nanosleep")
 int handle_kprobe(struct pt_regs *ctx)
@@ -39,4 +43,37 @@ int handle_uretprobe(struct pt_regs *ctx)
        return 0;
 }

+SEC("uprobe/trigger_func_byname")
+int handle_uprobe_byname(struct pt_regs *ctx)
+{
+       uprobe_byname_res = 5;
+       return 0;
+}
+
+/* use auto-attach format for section definition. */
+SEC("uretprobe//proc/self/exe:trigger_func2")
+int handle_uretprobe_byname(struct pt_regs *ctx)
+{
+       uretprobe_byname_res = 6;
+       return 0;
+}
+
+SEC("uprobe/trigger_func_byname2")
+int handle_uprobe_byname2(struct pt_regs *ctx)
this one is for malloc, so why SEC() doesn't reflect this?

It would be great to also have (probably separate) selftest for
auto-attach logic of skeleton for uprobes.
I'd add a separate uprobe-specific selftests, there is plenty to test
without having kprobes intermingled.
+{
+       unsigned int size = PT_REGS_PARM1(ctx);
+
+       /* verify malloc size */
+       if (size == 1)
+               uprobe_byname2_res = 7;
+       return 0;
+}
+
+SEC("uretprobe/trigger_func_byname2")
+int handle_uretprobe_byname2(struct pt_regs *ctx)
+{
+       uretprobe_byname2_res = 8;
+       return 0;
+}
+
 char _license[] SEC("license") = "GPL";
--
1.8.3.1
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