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charset="us-ascii" Content-ID: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: fcaeff1c-89cb-479c-a619-08d6f34eaf42 X-MS-Exchange-CrossTenant-originalarrivaltime: 17 Jun 2019 18:07:39.1712 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: songliubraving@fb.com X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR15MB1182 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-17_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906170162 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > On Jun 17, 2019, at 10:24 AM, Andrii Nakryiko = wrote: >=20 > On Sat, Jun 15, 2019 at 1:26 PM Song Liu wrote: >>=20 >> On Mon, Jun 10, 2019 at 9:49 PM Andrii Nakryiko wrote: >>>=20 >>> As a preparation for adding BTF-based BPF map loading, extract .BTF and >>> .BTF.ext loading logic. Also simplify error handling in >>> bpf_object__elf_collect() by returning early, as there is no common >>> clean up to be done. >>>=20 >>> Signed-off-by: Andrii Nakryiko >>> --- >>> tools/lib/bpf/libbpf.c | 137 ++++++++++++++++++++++------------------- >>> 1 file changed, 75 insertions(+), 62 deletions(-) >>>=20 >>> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c >>> index ba89d9727137..9e39a0a33aeb 100644 >>> --- a/tools/lib/bpf/libbpf.c >>> +++ b/tools/lib/bpf/libbpf.c >>> @@ -1078,6 +1078,58 @@ static void bpf_object__sanitize_btf_ext(struct = bpf_object *obj) >>> } >>> } >>>=20 >>> +static int bpf_object__load_btf(struct bpf_object *obj, >>> + Elf_Data *btf_data, >>> + Elf_Data *btf_ext_data) >>> +{ >>> + int err =3D 0; >>> + >>> + if (btf_data) { >>> + obj->btf =3D btf__new(btf_data->d_buf, btf_data->d_size= ); >>> + if (IS_ERR(obj->btf)) { >>> + pr_warning("Error loading ELF section %s: %d.\n= ", >>> + BTF_ELF_SEC, err); >>> + goto out; >>=20 >> If we goto out here, we will return 0. >=20 >=20 > Yes, it's intentional. BTF is treated as optional, so if we fail to > load it, libbpf will emit warning, but will proceed as nothing > happened and no BTF was supposed to be loaded. >=20 >>=20 >>> + } >>> + err =3D btf__finalize_data(obj, obj->btf); >>> + if (err) { >>> + pr_warning("Error finalizing %s: %d.\n", >>> + BTF_ELF_SEC, err); >>> + goto out; >>> + } >>> + bpf_object__sanitize_btf(obj); >>> + err =3D btf__load(obj->btf); >>> + if (err) { >>> + pr_warning("Error loading %s into kernel: %d.\n= ", >>> + BTF_ELF_SEC, err); >>> + goto out; >>> + } >>> + } >>> + if (btf_ext_data) { >>> + if (!obj->btf) { >>> + pr_debug("Ignore ELF section %s because its dep= ending ELF section %s is not found.\n", >>> + BTF_EXT_ELF_SEC, BTF_ELF_SEC); >>> + goto out; >>=20 >> We will also return 0 when goto out here. >=20 >=20 > See above, it's original behavior of libbpf. >=20 >>=20 >>> + } >>> + obj->btf_ext =3D btf_ext__new(btf_ext_data->d_buf, >>> + btf_ext_data->d_size); >>> + if (IS_ERR(obj->btf_ext)) { >>> + pr_warning("Error loading ELF section %s: %ld. = Ignored and continue.\n", >>> + BTF_EXT_ELF_SEC, PTR_ERR(obj->btf_ex= t)); >>> + obj->btf_ext =3D NULL; >>> + goto out; >> And, here. And we will not free obj->btf. >=20 > This is situation in which we successfully loaded .BTF, but failed to > load .BTF.ext. In that case we'll warn about .BTF.ext, but will drop > it and continue with .BTF only. >=20 Yeah, that makes sense.=20 Shall we let bpf_object__load_btf() return void? Since it always=20 returns 0? Thanks, Song