Hi Omar, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on linus/master] [also build test WARNING on v4.18-rc3 next-20180706] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Omar-Sandoval/proc-kcore-improvements/20180707-052548 reproduce: # apt-get install sparse make ARCH=x86_64 allmodconfig make C=1 CF=-D__CHECK_ENDIAN__ sparse warnings: (new ones prefixed by >>) include/linux/nodemask.h:265:16: sparse: expression using sizeof(void) include/linux/nodemask.h:271:16: sparse: expression using sizeof(void) >> fs//proc/kcore.c:328:23: sparse: expression using sizeof(void) >> fs//proc/kcore.c:328:23: sparse: expression using sizeof(void) fs//proc/kcore.c:368:23: sparse: expression using sizeof(void) fs//proc/kcore.c:368:23: sparse: expression using sizeof(void) >> fs//proc/kcore.c:384:49: sparse: missing braces around initializer fs//proc/kcore.c:408:23: sparse: expression using sizeof(void) fs//proc/kcore.c:408:23: sparse: expression using sizeof(void) vim +328 fs//proc/kcore.c 285 286 static ssize_t 287 read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) 288 { 289 char *buf = file->private_data; 290 size_t phdrs_offset, notes_offset, data_offset; 291 size_t phdrs_len, notes_len; 292 struct kcore_list *m; 293 size_t tsz; 294 int nphdr; 295 unsigned long start; 296 size_t orig_buflen = buflen; 297 int ret = 0; 298 299 down_read(&kclist_lock); 300 301 get_kcore_size(&nphdr, &phdrs_len, ¬es_len, &data_offset); 302 phdrs_offset = sizeof(struct elfhdr); 303 notes_offset = phdrs_offset + phdrs_len; 304 305 /* ELF file header. */ 306 if (buflen && *fpos < sizeof(struct elfhdr)) { 307 struct elfhdr ehdr = { 308 .e_ident = { 309 [EI_MAG0] = ELFMAG0, 310 [EI_MAG1] = ELFMAG1, 311 [EI_MAG2] = ELFMAG2, 312 [EI_MAG3] = ELFMAG3, 313 [EI_CLASS] = ELF_CLASS, 314 [EI_DATA] = ELF_DATA, 315 [EI_VERSION] = EV_CURRENT, 316 [EI_OSABI] = ELF_OSABI, 317 }, 318 .e_type = ET_CORE, 319 .e_machine = ELF_ARCH, 320 .e_version = EV_CURRENT, 321 .e_phoff = sizeof(struct elfhdr), 322 .e_flags = ELF_CORE_EFLAGS, 323 .e_ehsize = sizeof(struct elfhdr), 324 .e_phentsize = sizeof(struct elf_phdr), 325 .e_phnum = nphdr, 326 }; 327 > 328 tsz = min_t(size_t, buflen, sizeof(struct elfhdr) - *fpos); 329 if (copy_to_user(buffer, (char *)&ehdr + *fpos, tsz)) { 330 ret = -EFAULT; 331 goto out; 332 } 333 334 buffer += tsz; 335 buflen -= tsz; 336 *fpos += tsz; 337 } 338 339 /* ELF program headers. */ 340 if (buflen && *fpos < phdrs_offset + phdrs_len) { 341 struct elf_phdr *phdrs, *phdr; 342 343 phdrs = kzalloc(phdrs_len, GFP_KERNEL); 344 if (!phdrs) { 345 ret = -ENOMEM; 346 goto out; 347 } 348 349 phdrs[0].p_type = PT_NOTE; 350 phdrs[0].p_offset = notes_offset; 351 phdrs[0].p_filesz = notes_len; 352 353 phdr = &phdrs[1]; 354 list_for_each_entry(m, &kclist_head, list) { 355 phdr->p_type = PT_LOAD; 356 phdr->p_flags = PF_R | PF_W | PF_X; 357 phdr->p_offset = kc_vaddr_to_offset(m->addr) + data_offset; 358 phdr->p_vaddr = (size_t)m->addr; 359 if (m->type == KCORE_RAM || m->type == KCORE_TEXT) 360 phdr->p_paddr = __pa(m->addr); 361 else 362 phdr->p_paddr = (elf_addr_t)-1; 363 phdr->p_filesz = phdr->p_memsz = m->size; 364 phdr->p_align = PAGE_SIZE; 365 phdr++; 366 } 367 368 tsz = min_t(size_t, buflen, phdrs_offset + phdrs_len - *fpos); 369 if (copy_to_user(buffer, (char *)phdrs + *fpos - phdrs_offset, 370 tsz)) { 371 kfree(phdrs); 372 ret = -EFAULT; 373 goto out; 374 } 375 kfree(phdrs); 376 377 buffer += tsz; 378 buflen -= tsz; 379 *fpos += tsz; 380 } 381 382 /* ELF note segment. */ 383 if (buflen && *fpos < notes_offset + notes_len) { > 384 struct elf_prstatus prstatus = {0}; 385 struct elf_prpsinfo prpsinfo = { 386 .pr_sname = 'R', 387 .pr_fname = "vmlinux", 388 }; 389 char *notes; 390 size_t i = 0; 391 392 strlcpy(prpsinfo.pr_psargs, saved_command_line, 393 sizeof(prpsinfo.pr_psargs)); 394 395 notes = kzalloc(notes_len, GFP_KERNEL); 396 if (!notes) { 397 ret = -ENOMEM; 398 goto out; 399 } 400 401 append_kcore_note(notes, &i, CORE_STR, NT_PRSTATUS, &prstatus, 402 sizeof(prstatus)); 403 append_kcore_note(notes, &i, CORE_STR, NT_PRPSINFO, &prpsinfo, 404 sizeof(prpsinfo)); 405 append_kcore_note(notes, &i, CORE_STR, NT_TASKSTRUCT, current, 406 arch_task_struct_size); 407 408 tsz = min_t(size_t, buflen, notes_offset + notes_len - *fpos); 409 if (copy_to_user(buffer, notes + *fpos - notes_offset, tsz)) { 410 kfree(notes); 411 ret = -EFAULT; 412 goto out; 413 } 414 kfree(notes); 415 416 buffer += tsz; 417 buflen -= tsz; 418 *fpos += tsz; 419 } 420 421 /* 422 * Check to see if our file offset matches with any of 423 * the addresses in the elf_phdr on our list. 424 */ 425 start = kc_offset_to_vaddr(*fpos - data_offset); 426 if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen) 427 tsz = buflen; 428 429 while (buflen) { 430 list_for_each_entry(m, &kclist_head, list) { 431 if (start >= m->addr && start < (m->addr+m->size)) 432 break; 433 } 434 435 if (&m->list == &kclist_head) { 436 if (clear_user(buffer, tsz)) { 437 ret = -EFAULT; 438 goto out; 439 } 440 } else if (m->type == KCORE_VMALLOC) { 441 vread(buf, (char *)start, tsz); 442 /* we have to zero-fill user buffer even if no read */ 443 if (copy_to_user(buffer, buf, tsz)) { 444 ret = -EFAULT; 445 goto out; 446 } 447 } else if (m->type == KCORE_USER) { 448 /* User page is handled prior to normal kernel page: */ 449 if (copy_to_user(buffer, (char *)start, tsz)) { 450 ret = -EFAULT; 451 goto out; 452 } 453 } else { 454 if (kern_addr_valid(start)) { 455 /* 456 * Using bounce buffer to bypass the 457 * hardened user copy kernel text checks. 458 */ 459 if (probe_kernel_read(buf, (void *) start, tsz)) { 460 if (clear_user(buffer, tsz)) { 461 ret = -EFAULT; 462 goto out; 463 } 464 } else { 465 if (copy_to_user(buffer, buf, tsz)) { 466 ret = -EFAULT; 467 goto out; 468 } 469 } 470 } else { 471 if (clear_user(buffer, tsz)) { 472 ret = -EFAULT; 473 goto out; 474 } 475 } 476 } 477 buflen -= tsz; 478 *fpos += tsz; 479 buffer += tsz; 480 start += tsz; 481 tsz = (buflen > PAGE_SIZE ? PAGE_SIZE : buflen); 482 } 483 484 out: 485 up_write(&kclist_lock); 486 if (ret) 487 return ret; 488 return orig_buflen - buflen; 489 } 490 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
