Re: [PATCH bpf-next 6/9] bpf: Factor callchain_store function from __bpf_get_stack

[Jiri Olsa <olsajiri@gmail.com>]

On Mon, Jul 20, 2026 at 09:07:20AM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Low] The 'size' parameter in callchain_store() is unused.
> --
> 
> --- Patch [6]: [PATCH bpf-next 6/9] bpf: Factor callchain_store function from __bpf_get_stack ---
> commit aee65ba10526fcf4c6320ea660fc50a555551cc1
> Author: Jiri Olsa <jolsa@kernel.org>
> 
> bpf: Factor callchain_store function from __bpf_get_stack
> 
> This commit extracts the logic for storing trace entries into a user-supplied
> buffer from __bpf_get_stack() and places it into a new helper function named
> callchain_store().
> 
> > diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
> > index a64b14ffd1e8e..b990643f25cd8 100644
> > --- a/kernel/bpf/stackmap.c
> > +++ b/kernel/bpf/stackmap.c
> [ ... ]
> > @@ -747,6 +747,29 @@ const struct bpf_func_proto bpf_get_stackid_proto_pe = {
> >  	.arg3_type	= ARG_ANYTHING,
> >  };
> >  
> > +static u32 callchain_store(struct perf_callchain_entry *trace, void *buf, u32 size,
> > +			   u32 elem_size, u64 flags)
> 
> [Severity: Low]
> This isn't a bug, but the 'size' parameter doesn't appear to be used anywhere
> within callchain_store() in kernel/bpf/stackmap.c. Could it be safely removed
> from the function signature since the bounds checking is handled in the caller?

true, will remove

jirka