On Tue, Feb 25, 2025 at 12:53 PM Martin KaFai Lau <martin.lau@xxxxxxxxx> wrote:
>
> On 2/21/25 8:47 AM, Amery Hung wrote:
> > +static int st_ops_gen_epilogue_with_kfunc(struct bpf_insn *insn_buf, const struct bpf_prog *prog,
> > + s16 ctx_stack_off)
> > +{
> > + struct bpf_insn *insn = insn_buf;
> > +
> > + /* r1 = 0;
> > + * r0 = bpf_cgroup_from_id(r1);
> > + * if r0 != 0 goto pc+6;
> > + * r1 = stack[ctx_stack_off]; // r1 will be "u64 *ctx"
> > + * r1 = r1[0]; // r1 will be "struct st_ops *args"
> > + * r6 = r1->a;
> > + * r6 += 10000;
> > + * r1->a = r6;
> > + * goto pc+2
> > + * r1 = r0;
> > + * bpf_cgroup_release(r1);
> > + * r0 = r6;
>
> I think r6 is not initialized on the "r0 != 0" case.
>
I will insert r6 = 0 after the first epilogue instruction.
Thanks,
Amery
> Others lgtm.
>
