On Apr 24 2024, Benjamin Tissoires wrote: > On Apr 23 2024, Dan Carpenter wrote: > > Hi Benjamin, > > > > kernel test robot noticed the following build warnings: > > > > url: https://github.com/intel-lab-lkp/linux/commits/Benjamin-Tissoires/HID-bpf-fix-a-comment-in-a-define/20240419-225110 > > base: b912cf042072e12e93faa874265b30cc0aa521b9 > > patch link: https://lore.kernel.org/r/20240419-hid_bpf_lazy_skel-v1-3-9210bcd4b61c%40kernel.org > > patch subject: [PATCH 3/3] HID: bpf: lazy load the hid_tail_call entrypoint > > config: i386-randconfig-141-20240423 (https://download.01.org/0day-ci/archive/20240423/202404231109.h2IRrMMD-lkp@xxxxxxxxx/config) > > compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18) > > > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > > the same patch/commit), kindly add following tags > > | Reported-by: kernel test robot <lkp@xxxxxxxxx> > > | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > > | Closes: https://lore.kernel.org/r/202404231109.h2IRrMMD-lkp@xxxxxxxxx/ > > > > smatch warnings: > > drivers/hid/bpf/hid_bpf_jmp_table.c:478 __hid_bpf_attach_prog() error: uninitialized symbol 'link'. > > > > vim +/link +478 drivers/hid/bpf/hid_bpf_jmp_table.c > > > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 396 noinline int > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 397 __hid_bpf_attach_prog(struct hid_device *hdev, enum hid_bpf_prog_type prog_type, > > 7cdd2108903a4e3 Benjamin Tissoires 2024-01-24 398 int prog_fd, struct bpf_prog *prog, __u32 flags) > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 399 { > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 400 struct bpf_link_primer link_primer; > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 401 struct hid_bpf_link *link; > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 402 struct hid_bpf_prog_entry *prog_entry; > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 403 int cnt, err = -EINVAL, prog_table_idx = -1; > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 404 > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 405 mutex_lock(&hid_bpf_attach_lock); > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 406 > > 60caa381da7dc38 Benjamin Tissoires 2024-04-19 407 if (!jmp_table.map) { > > 60caa381da7dc38 Benjamin Tissoires 2024-04-19 408 err = hid_bpf_preload_skel(); > > 60caa381da7dc38 Benjamin Tissoires 2024-04-19 409 WARN_ONCE(err, "error while preloading HID BPF dispatcher: %d", err); > > 60caa381da7dc38 Benjamin Tissoires 2024-04-19 410 if (err) > > 60caa381da7dc38 Benjamin Tissoires 2024-04-19 411 goto err_unlock; > > ^^^^^^^^^^^^^^^^ > > link isn't initialized. > > Well spotted! Thanks > I'll send a v2 soon. FWIW, this patch prevents the proper unloading of the HID-BPF programs. So not sure we'll want it as such just now. Cheers, Benjamin > > > > 60caa381da7dc38 Benjamin Tissoires 2024-04-19 412 } > > 60caa381da7dc38 Benjamin Tissoires 2024-04-19 413 > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 414 link = kzalloc(sizeof(*link), GFP_USER); > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 415 if (!link) { > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 416 err = -ENOMEM; > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 417 goto err_unlock; > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 418 } > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 419 > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 420 bpf_link_init(&link->link, BPF_LINK_TYPE_UNSPEC, > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 421 &hid_bpf_link_lops, prog); > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 422 > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 423 /* do not attach too many programs to a given HID device */ > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 424 cnt = hid_bpf_program_count(hdev, NULL, prog_type); > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 425 if (cnt < 0) { > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 426 err = cnt; > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 427 goto err_unlock; > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 428 } > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 429 > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 430 if (cnt >= hid_bpf_max_programs(prog_type)) { > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 431 err = -E2BIG; > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 432 goto err_unlock; > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 433 } > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 434 > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 435 prog_table_idx = hid_bpf_insert_prog(prog_fd, prog); > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 436 /* if the jmp table is full, abort */ > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 437 if (prog_table_idx < 0) { > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 438 err = prog_table_idx; > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 439 goto err_unlock; > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 440 } > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 441 > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 442 if (flags & HID_BPF_FLAG_INSERT_HEAD) { > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 443 /* take the previous prog_entry slot */ > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 444 jmp_table.tail = PREV(jmp_table.tail); > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 445 prog_entry = &jmp_table.entries[jmp_table.tail]; > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 446 } else { > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 447 /* take the next prog_entry slot */ > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 448 prog_entry = &jmp_table.entries[jmp_table.head]; > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 449 jmp_table.head = NEXT(jmp_table.head); > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 450 } > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 451 > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 452 /* we steal the ref here */ > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 453 prog_entry->prog = prog; > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 454 prog_entry->idx = prog_table_idx; > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 455 prog_entry->hdev = hdev; > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 456 prog_entry->type = prog_type; > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 457 > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 458 /* finally store the index in the device list */ > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 459 err = hid_bpf_populate_hdev(hdev, prog_type); > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 460 if (err) { > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 461 hid_bpf_release_prog_at(prog_table_idx); > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 462 goto err_unlock; > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 463 } > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 464 > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 465 link->hid_table_index = prog_table_idx; > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 466 > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 467 err = bpf_link_prime(&link->link, &link_primer); > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 468 if (err) > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 469 goto err_unlock; > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 470 > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 471 mutex_unlock(&hid_bpf_attach_lock); > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 472 > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 473 return bpf_link_settle(&link_primer); > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 474 > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 475 err_unlock: > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 476 mutex_unlock(&hid_bpf_attach_lock); > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 477 > > 4b9a3f49f02bf68 Benjamin Tissoires 2023-01-13 @478 kfree(link); > > ^^^^ > > > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 479 > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 480 return err; > > f5c27da4e3c8a2e Benjamin Tissoires 2022-11-03 481 } > > > > -- > > 0-DAY CI Kernel Test Service > > https://github.com/intel/lkp-tests/wiki > >
