Re: [PATCH bpf-next 3/3] bpf: Force cookies array to follow symbols sorting

[Song Liu]

> On May 27, 2022, at 1:56 PM, Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> 
> When user specifies symbols and cookies for kprobe_multi link
> interface it's very likely the cookies will be misplaced and
> returned to wrong functions (via get_attach_cookie helper).
> 
> The reason is that to resolve the provided functions we sort
> them before passing them to ftrace_lookup_symbols, but we do
> not do the same sort on the cookie values.
> 
> Fixing this by using sort_r function with custom swap callback
> that swaps cookie values as well.
> 
> Fixes: 0236fec57a15 ("bpf: Resolve symbols with ftrace_lookup_symbols for kprobe multi link")
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx

Acked-by: Song Liu <songliubraving@xxxxxx>