Re: [PATCH 3/4] perf c2c: Add stdio support for the function view

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [Medium] Memory leak: L2 and L3 function-view child entries are not freed on cleanup because `perf c2c` does not set `symbol_conf.report_hierarchy`, bypassing the recursive deletion in `hist_entry__delete()`.
--

--- Patch [3]: [PATCH 3/4] perf c2c: Add stdio support for the function view ---
commit e1f0ed49bafb9da749fbfa14e02ab8497ae9d5d4
Author: Jiebin Sun <jiebin.sun@intel.com>

perf c2c: Add stdio support for the function view

This commit adds a --function option to perf c2c to print the fully expanded
three-level hierarchy to stdout, allowing its use without SLANG support,
when piped, or in scripts. It reuses the common function-view model while
preserving the boundary between utilities and the UI.

> diff --git a/tools/perf/util/c2c-function.c b/tools/perf/util/c2c-function.c
> --- a/tools/perf/util/c2c-function.c
> +++ b/tools/perf/util/c2c-function.c

[ ... ]

> @@ -1519,7 +1516,7 @@ void c2c_function__reset(void)
>  	symbol_conf.use_callchain = saved_use_callchain;
>  }

[Severity: Medium]
This is a pre-existing issue, but does this teardown logic in
c2c_function__reset() leak the L2 and L3 function-view child entries?

When cleaning up the hierarchy, hists__delete_all_entries() relies on
hist_entry__delete() for each node. However, in tools/perf/util/hist.c,
hist_entry__delete() only recursively deletes the child entries in hroot_out
if the hierarchy flag is set:

tools/perf/util/hist.c:hist_entry__delete() {
    ...
    if (symbol_conf.report_hierarchy) {
        struct rb_root *root = &he->hroot_out.rb_root;
        struct hist_entry *child, *tmp;

        rbtree_postorder_for_each_entry_safe(child, tmp, root, rb_node)
            hist_entry__delete(child);

        *root = RB_ROOT;
    }
    ...
}

Since perf c2c does not appear to set symbol_conf.report_hierarchy, won't
these child entries be orphaned and skipped during cleanup?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/cover.1787283281.git.jiebin.sun@intel.com?part=3