Hi Eric, kernel test robot noticed the following build warnings: https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Eric-W-Biederman/binfmt_elf-Support-segments-with-0-filesz-and-misaligned-starts/20230925-210022 base: https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git for-next/execve patch link: https://lore.kernel.org/r/87jzsemmsd.fsf_-_%40email.froward.int.ebiederm.org patch subject: [PATCH] binfmt_elf: Support segments with 0 filesz and misaligned starts config: i386-randconfig-141-20230926 (https://download.01.org/0day-ci/archive/20230926/202309261925.QvgPAYL7-lkp@xxxxxxxxx/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce: (https://download.01.org/0day-ci/archive/20230926/202309261925.QvgPAYL7-lkp@xxxxxxxxx/reproduce) 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/202309261925.QvgPAYL7-lkp@xxxxxxxxx/ smatch warnings: fs/binfmt_elf.c:431 elf_load() error: uninitialized symbol 'map_addr'. vim +/map_addr +431 fs/binfmt_elf.c a6409120b31666 Eric W. Biederman 2023-09-25 390 static unsigned long elf_load(struct file *filep, unsigned long addr, a6409120b31666 Eric W. Biederman 2023-09-25 391 const struct elf_phdr *eppnt, int prot, int type, a6409120b31666 Eric W. Biederman 2023-09-25 392 unsigned long total_size) a6409120b31666 Eric W. Biederman 2023-09-25 393 { a6409120b31666 Eric W. Biederman 2023-09-25 394 unsigned long zero_start, zero_end; a6409120b31666 Eric W. Biederman 2023-09-25 395 unsigned long map_addr; a6409120b31666 Eric W. Biederman 2023-09-25 396 a6409120b31666 Eric W. Biederman 2023-09-25 397 if (eppnt->p_filesz) { a6409120b31666 Eric W. Biederman 2023-09-25 398 map_addr = elf_map(filep, addr, eppnt, prot, type, total_size); a6409120b31666 Eric W. Biederman 2023-09-25 399 if (BAD_ADDR(map_addr)) a6409120b31666 Eric W. Biederman 2023-09-25 400 return map_addr; a6409120b31666 Eric W. Biederman 2023-09-25 401 if (eppnt->p_memsz > eppnt->p_filesz) { a6409120b31666 Eric W. Biederman 2023-09-25 402 zero_start = map_addr + ELF_PAGEOFFSET(eppnt->p_vaddr) + a6409120b31666 Eric W. Biederman 2023-09-25 403 eppnt->p_filesz; a6409120b31666 Eric W. Biederman 2023-09-25 404 zero_end = map_addr + ELF_PAGEOFFSET(eppnt->p_vaddr) + a6409120b31666 Eric W. Biederman 2023-09-25 405 eppnt->p_memsz; a6409120b31666 Eric W. Biederman 2023-09-25 406 a6409120b31666 Eric W. Biederman 2023-09-25 407 /* Zero the end of the last mapped page */ a6409120b31666 Eric W. Biederman 2023-09-25 408 padzero(zero_start); a6409120b31666 Eric W. Biederman 2023-09-25 409 } a6409120b31666 Eric W. Biederman 2023-09-25 410 } else { a6409120b31666 Eric W. Biederman 2023-09-25 411 zero_start = ELF_PAGESTART(addr); a6409120b31666 Eric W. Biederman 2023-09-25 412 zero_end = zero_start + ELF_PAGEOFFSET(eppnt->p_vaddr) + a6409120b31666 Eric W. Biederman 2023-09-25 413 eppnt->p_memsz; For this else path, map_addr is only set if there is an error. a6409120b31666 Eric W. Biederman 2023-09-25 414 } a6409120b31666 Eric W. Biederman 2023-09-25 415 if (eppnt->p_memsz > eppnt->p_filesz) { a6409120b31666 Eric W. Biederman 2023-09-25 416 /* a6409120b31666 Eric W. Biederman 2023-09-25 417 * Map the last of the segment. a6409120b31666 Eric W. Biederman 2023-09-25 418 * If the header is requesting these pages to be a6409120b31666 Eric W. Biederman 2023-09-25 419 * executable, honour that (ppc32 needs this). a6409120b31666 Eric W. Biederman 2023-09-25 420 */ a6409120b31666 Eric W. Biederman 2023-09-25 421 int error; a6409120b31666 Eric W. Biederman 2023-09-25 422 a6409120b31666 Eric W. Biederman 2023-09-25 423 zero_start = ELF_PAGEALIGN(zero_start); a6409120b31666 Eric W. Biederman 2023-09-25 424 zero_end = ELF_PAGEALIGN(zero_end); a6409120b31666 Eric W. Biederman 2023-09-25 425 a6409120b31666 Eric W. Biederman 2023-09-25 426 error = vm_brk_flags(zero_start, zero_end - zero_start, a6409120b31666 Eric W. Biederman 2023-09-25 427 prot & PROT_EXEC ? VM_EXEC : 0); a6409120b31666 Eric W. Biederman 2023-09-25 428 if (error) a6409120b31666 Eric W. Biederman 2023-09-25 429 map_addr = error; a6409120b31666 Eric W. Biederman 2023-09-25 430 } a6409120b31666 Eric W. Biederman 2023-09-25 @431 return map_addr; a6409120b31666 Eric W. Biederman 2023-09-25 432 } -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
