diff options
| author | Chuang Wang <nashuiliang@gmail.com> | 2022-06-29 18:18:47 +0300 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2022-07-06 07:23:03 +0300 |
| commit | 2655144fb49bae26eae038c6d056f824a7db2726 (patch) | |
| tree | 777cb0284845c78e21a0d861a5b1eab6e54f73c2 /tools/lib/bpf/libbpf.c | |
| parent | 5666fc997ccb93859ea1d4437936c64c6d75c060 (diff) | |
| download | linux-2655144fb49bae26eae038c6d056f824a7db2726.tar.xz | |
libbpf: Cleanup the legacy uprobe_event on failed add/attach_event()
A potential scenario, when an error is returned after
add_uprobe_event_legacy() in perf_event_uprobe_open_legacy(), or
bpf_program__attach_perf_event_opts() in
bpf_program__attach_uprobe_opts() returns an error, the uprobe_event
that was previously created is not cleaned.
So, with this patch, when an error is returned, fix this by adding
remove_uprobe_event_legacy()
Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220629151848.65587-4-nashuiliang@gmail.com
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 571acd614dce..cb49408eb298 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -10248,9 +10248,10 @@ static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe, } type = determine_uprobe_perf_type_legacy(probe_name, retprobe); if (type < 0) { + err = type; pr_warn("failed to determine legacy uprobe event id for %s:0x%zx: %d\n", - binary_path, offset, type); - return type; + binary_path, offset, err); + goto err_clean_legacy; } memset(&attr, 0, sizeof(attr)); @@ -10265,9 +10266,14 @@ static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe, if (pfd < 0) { err = -errno; pr_warn("legacy uprobe perf_event_open() failed: %d\n", err); - return err; + goto err_clean_legacy; } return pfd; + +err_clean_legacy: + /* Clear the newly added legacy uprobe_event */ + remove_uprobe_event_legacy(probe_name, retprobe); + return err; } /* Return next ELF section of sh_type after scn, or first of that type if scn is NULL. */ @@ -10601,7 +10607,7 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, prog->name, retprobe ? "uretprobe" : "uprobe", binary_path, func_offset, libbpf_strerror_r(err, errmsg, sizeof(errmsg))); - goto err_out; + goto err_clean_legacy; } if (legacy) { struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link); @@ -10611,10 +10617,13 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, perf_link->legacy_is_retprobe = retprobe; } return link; + +err_clean_legacy: + if (legacy) + remove_uprobe_event_legacy(legacy_probe, retprobe); err_out: free(legacy_probe); return libbpf_err_ptr(err); - } /* Format of u[ret]probe section definition supporting auto-attach: |