diff options
Diffstat (limited to 'tools/perf/util/unwind-libdw.c')
| -rw-r--r-- | tools/perf/util/unwind-libdw.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c index 05e8e68bd49c..7f35042be567 100644 --- a/tools/perf/util/unwind-libdw.c +++ b/tools/perf/util/unwind-libdw.c @@ -339,7 +339,7 @@ frame_callback(Dwfl_Frame *state, void *arg) DWARF_CB_ABORT : DWARF_CB_OK; } -int unwind__get_entries(unwind_entry_cb_t cb, void *arg, +int libdw__get_entries(unwind_entry_cb_t cb, void *arg, struct thread *thread, struct perf_sample *data, int max_stack, @@ -353,10 +353,10 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg, static struct unwind_info *ui; Dwfl *dwfl; Dwarf_Word ip; - int err = -EINVAL, i; + int err = -EINVAL, i, entries; if (!data->user_regs || !data->user_regs->regs) - return -EINVAL; + return 0; ui = zalloc(sizeof(*ui) + sizeof(ui->entries[0]) * max_stack); if (!ui) @@ -430,6 +430,18 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg, map_symbol__exit(&ui->entries[i].ms); dwfl_ui_ti->ui = NULL; + entries = (int)ui->idx; free(ui); - return 0; + /* + * Unwinder return contract: + * > 0 : unwinding succeeded (stops fallback). If we found frames but hit an error + * (e.g. truncated stack), report success to preserve existing frames. + * 0 : unwinding failed without yielding frames. Ignore non-fatal errors + * (e.g. missing debug info, DWARF corruption) to allow fallback unwinder or + * kernel callchain resolution to proceed. + * < 0 : fatal error (e.g. -ENOMEM). Aborts unwinding entirely. + */ + if (err) + return (err == -ENOMEM) ? -ENOMEM : (entries > 0 ? 1 : 0); + return entries; } |