Re: [PATCH v2] bpf: s390: add JIT support for multi-function programs

[Ilya Leoshkevich <iii@linux.ibm.com>]

> Am 27.08.2019 um 16:53 schrieb Yauheni Kaliuta <yauheni.kaliuta@redhat.com>:
> 
> @@ -1316,7 +1327,9 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
> {
> 	struct bpf_prog *tmp, *orig_fp = fp;
> 	struct bpf_binary_header *header;
> +	struct s390_jit_data *jit_data;
> 	bool tmp_blinded = false;
> +	bool extra_pass = false;
> 	struct bpf_jit jit;
> 	int pass;
> 
> @@ -1335,6 +1348,22 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
> 		fp = tmp;
> 	}
> 
> +	jit_data = fp->aux->jit_data;
> +	if (!jit_data) {
> +		jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL);
> +		if (!jit_data) {
> +			fp = orig_fp;
> +			goto out;
> +		}
> +		fp->aux->jit_data = jit_data;
> +	}
> +	if (jit_data->ctx.addrs) {
> +		jit = jit_data->ctx;
> +		header = jit_data->header;
> +		extra_pass = true;
> +		goto skip_init_ctx;
> +	}
> +

I've noticed that I'm getting the following warning, presumably because
of the added goto skip_init_ctx:

linux/arch/s390/net/bpf_jit_comp.c: In function 'bpf_int_jit_compile':
linux/arch/s390/net/bpf_jit_comp.c:1406:3: warning: 'pass' may be used uninitialized in this function [-Wmaybe-uninitialized]
   bpf_jit_dump(fp->len, jit.size, pass, jit.prg_buf);

Maybe set the initial value of pass to 1?