On Mon, Jan 06, 2020 at 03:46:40PM -0800, Alexei Starovoitov wrote:
> On Sun, Dec 29, 2019 at 03:37:40PM +0100, Jiri Olsa wrote:
> > When unwinding the stack we need to identify each
> > address to successfully continue. Adding latch tree
> > to keep trampolines for quick lookup during the
> > unwind.
> >
> > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ...
> > +bool is_bpf_trampoline(void *addr)
> > +{
> > + return latch_tree_find(addr, &tree, &tree_ops) != NULL;
> > +}
> > +
> > struct bpf_trampoline *bpf_trampoline_lookup(u64 key)
> > {
> > struct bpf_trampoline *tr;
> > @@ -65,6 +98,7 @@ struct bpf_trampoline *bpf_trampoline_lookup(u64 key)
> > for (i = 0; i < BPF_TRAMP_MAX; i++)
> > INIT_HLIST_HEAD(&tr->progs_hlist[i]);
> > tr->image = image;
> > + latch_tree_insert(&tr->tnode, &tree, &tree_ops);
>
> Thanks for the fix. I was thinking to apply it, but then realized that bpf
> dispatcher logic has the same issue.
> Could you generalize the fix for both?
> May be bpf_jit_alloc_exec_page() can do latch_tree_insert() ?
> and new version of bpf_jit_free_exec() is needed that will do latch_tree_erase().
> Wdyt?
I need to check the dispatcher code, but seems ok.. will check
jirka
