From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============6851076486495107930==" MIME-Version: 1.0 From: kernel test robot Subject: Re: [RFC][PATCH] iov_iter: Add extraction functions Date: Mon, 12 Sep 2022 08:44:39 +0800 Message-ID: <202209120843.RvCuk9sv-lkp@intel.com> List-Id: To: kbuild@lists.01.org --===============6851076486495107930== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable :::::: = :::::: Manual check reason: "low confidence bisect report" :::::: Manual check reason: "low confidence static check warning: lib/iov_i= ter_extract.c:348:21: warning: use of uninitialized value 'ret' [CWE-457] [= -Wanalyzer-use-of-uninitialized-value]" :::::: = BCC: lkp(a)intel.com CC: kbuild-all(a)lists.01.org In-Reply-To: <3750754.1662765490@warthog.procyon.org.uk> References: <3750754.1662765490@warthog.procyon.org.uk> TO: David Howells Hi David, [FYI, it's a private test report for your RFC patch.] [auto build test WARNING on linus/master] [also build test WARNING on v6.0-rc5 next-20220909] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/David-Howells/iov_it= er-Add-extraction-functions/20220910-072102 base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git = ce888220d5c7a805e0e155302a318d5d23e62950 :::::: branch date: 2 days ago :::::: commit date: 2 days ago config: arm-randconfig-c002-20220911 (https://download.01.org/0day-ci/archi= ve/20220912/202209120843.RvCuk9sv-lkp(a)intel.com/config) compiler: arm-linux-gnueabi-gcc (GCC) 12.1.0 reproduce (this is a W=3D1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/= make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/intel-lab-lkp/linux/commit/a8df8a897880379087a= 0a9fc4f6fc1391e352217 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review David-Howells/iov_iter-Add-extract= ion-functions/20220910-072102 git checkout a8df8a897880379087a0a9fc4f6fc1391e352217 # save the config file COMPILER_INSTALL_PATH=3D$HOME/0day COMPILER=3Dgcc-12.1.0 make.cross= ARCH=3Darm KBUILD_USERCFLAGS=3D'-fanalyzer -Wno-error' = If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot gcc_analyzer warnings: (new ones prefixed by >>) lib/iov_iter_extract.c: In function 'iov_iter_extract_xarray': >> lib/iov_iter_extract.c:348:21: warning: use of uninitialized value 'ret'= [CWE-457] [-Wanalyzer-use-of-uninitialized-value] 348 | ret +=3D len; | ^~ 'iov_iter_extract_pages.part.0': events 1-8 | | 363 | static ssize_t iov_iter_extract_pages(struct iov_iter *iter, | | ^~~~~~~~~~~~~~~~~~~~~~ | | | | | (1) entry to 'iov_iter_extract_pages.part.0' |...... | 371 | if (iov_iter_is_bvec(iter)) | | ~ = | | | | | (2) following 'false' branch... |...... | 374 | if (iov_iter_is_kvec(iter)) | | ~ = | | | | | (3) ...to here | | (4) following 'false' branch... |...... | 377 | if (iov_iter_is_xarray(iter)) | | ~ = | | | | | (5) ...to here | | (6) following 'true' branch... | 378 | return iov_iter_extract_xarray(iter, array,= array_max, maxsize, | | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~= ~~~~~~~~~~~~~~~~~~~~ | | | | | (7) ...to here | | (8) calling 'iov_iter_extract_xarray= ' from 'iov_iter_extract_pages.part.0' | 379 | dest); | | ~~~~~ | +--> 'iov_iter_extract_xarray': events 9-10 | | 319 | static ssize_t iov_iter_extract_xarray(struct iov_it= er *iter, | | ^~~~~~~~~~~~~~~~~~~~~~~ | | | | | (9) entry to 'iov_iter_extract_xarray' |...... | 329 | ssize_t ret; | | ~~~ | | | | | (10) region created on stack here | 'iov_iter_extract_xarray': event 11 | | 334 | xas_for_each(&xas, folio, ULONG_MAX) { | | ^~~~~ | | | | | (11) following 'true' bra= nch (when 'folio' is non-NULL)... include/linux/xarray.h:1770:42: note: in definition of macro 'xas_for_ea= ch' | 1770 | for (entry =3D xas_find(xas, max); entry; \ | | ^~~~~ | 'iov_iter_extract_xarray': event 12 | |include/linux/compiler.h:78:42: | 78 | # define unlikely(x) __builtin_expect(!!(x), 0) | | ^~~~~ | | | | | (12) ...to = here include/linux/xarray.h:187:16: note: in expansion of macro 'unlikely' | 187 | return unlikely(entry =3D=3D XA_ZERO_ENTRY); | | ^~~~~~~~ | 'iov_iter_extract_xarray': event 13 | | 1506 | if (xa_is_zero(entry)) | | ^ | | | | | (13) following 'false' branch... | 'iov_iter_extract_xarray': event 14 | |include/linux/compiler.h:78:42: | 78 | # define unlikely(x) __builtin_expect(!!(x), 0) | | ^~~~~ | | | | | (14) ...to = here include/linux/xarray.h:1279:16: note: in expansion of macro 'unlikely' | 1279 | return unlikely(entry =3D=3D XA_RETRY_ENTRY); | | ^~~~~~~~ | 'iov_iter_extract_xarray': events 15-16 | | 81 | return (unsigned long)entry & 1; | | ~~~~~~~~~~~~~~~~~~~~ | | | | | (16) ...to here |...... | 1508 | if (!xa_is_retry(entry)) | | ^ | | | | | (15) following 'true' branch... | 'iov_iter_extract_xarray': event 17 | |lib/iov_iter_extract.c:337:20: | 337 | if (WARN_ON(xa_is_value(folio))) | | ^ | | | | | (17) following 'false' branch... | 'iov_iter_extract_xarray': event 18 | |include/linux/mm.h:1771:36: | 1771 | #define offset_in_folio(folio, p) ((unsigned long)(p= ) & (folio_size(folio) - 1)) | | ^~~~~~~~~~~~~~~~~~ | | | | | (18) ...to here lib/iov_iter_extract.c:342:26: note: in expansion of macro 'offset_in_fo= lio' | 342 | offset =3D offset_in_folio(folio, st= art); | | ^~~~~~~~~~~~~~~ | 'iov_iter_extract_xarray': event 19 | | 348 | ret +=3D len; | | ^~ | | | | | (19) use of uninitialized value = 'ret' here | >> lib/iov_iter_extract.c:348:21: warning: use of uninitialized value 'ret'= [CWE-457] [-Wanalyzer-use-of-uninitialized-value] 'extract_iter_to_sg': events 1-2 | | 477 | ssize_t extract_iter_to_sg(struct iov_iter *iter, size_t le= n, | | ^~~~~~~~~~~~~~~~~~ | | | | | (1) entry to 'extract_iter_to_sg' |...... | 504 | if (!sg) | | ~ | | | | | (2) following 'false' branch... | 'extract_iter_to_sg': event 3 | |include/linux/fortify-string.h:280:9: | 280 | fortify_memset_chk(__fortify_size, p_size, p_size_f= ield), \ | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~= ~~~~~ | | | | | (3) ...to here include/linux/fortify-string.h:288:25: note: in expansion of macro '__fo= rtify_memset_chk' | 288 | #define memset(p, c, s) __fortify_memset_chk(p, c, s, = \ | | ^~~~~~~~~~~~~~~~~~~~ lib/iov_iter_extract.c:506:9: note: in expansion of macro 'memset' | 506 | memset(sg, 0, sg_size); | | ^~~~~~ | 'extract_iter_to_sg': event 4 | | 511 | ret =3D iov_iter_extract_pages(iter, sgtable, sg_ma= x, len, | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~= ~~~~~ | | | | | (4) calling 'iov_iter_extract_pages' from 'ex= tract_iter_to_sg' | 512 | EXTRACT_TO_SGLIST); | | ~~~~~~~~~~~~~~~~~~ | +--> 'iov_iter_extract_pages': events 5-6 | | 363 | static ssize_t iov_iter_extract_pages(struct iov_ite= r *iter, | | ^~~~~~~~~~~~~~~~~~~~~~ | | | | | (5) entry to 'iov_iter_extract_pages' |...... | 368 | if (likely(user_backed_iter(iter))) | | ~ = | | | | | (6) following 'false' branch... | 'iov_iter_extract_pages': event 7 | |cc1: | (7): ...to here | 'iov_iter_extract_pages': event 8 | |cc1: | (8): calling 'iov_iter_extract_pages.part.0' from 'iov_iter= _extract_pages' | +--> 'iov_iter_extract_pages.part.0': events 9-16 | | 363 | static ssize_t iov_iter_extract_pages(struct = iov_iter *iter, | | ^~~~~~~~~~~~~~~~~~~~~~ | | | | | (9) entry to 'iov_iter_extract= _pages.part.0' |...... | 371 | if (iov_iter_is_bvec(iter)) | | ~ = | | | | | (10) following 'false' branch... |...... | 374 | if (iov_iter_is_kvec(iter)) | | ~ = | | | | | (11) ...to here | | (12) following 'false' branch... |...... | 377 | if (iov_iter_is_xarray(iter)) | | ~ = | | | | | (13) ...to here | | (14) following 'true' branch... | 378 | return iov_iter_extract_xarra= y(iter, array, array_max, maxsize, | | ~~~~~~~~~~~~~~~~~~~~~~= ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | | | | | (15) ...to here | | (16) calling 'iov_iter= _extract_xarray' from 'iov_iter_extract_pages.part.0' | 379 | = dest); | | = ~~~~~ | +--> 'iov_iter_extract_xarray': events 17-18 | | 319 | static ssize_t iov_iter_extract_xarray= (struct iov_iter *iter, | | ^~~~~~~~~~~~~~~~~~~~~~~ | | | | | (17) entry to 'iov_iter= _extract_xarray' |...... | 329 | ssize_t ret; | | ~~~ | | | | | (18) region created on= stack here | vim +/ret +348 lib/iov_iter_extract.c a8df8a89788037 David Howells 2022-09-10 314 = a8df8a89788037 David Howells 2022-09-10 315 /* a8df8a89788037 David Howells 2022-09-10 316 * Extract the pages from an = XARRAY-class iterator and add them to the a8df8a89788037 David Howells 2022-09-10 317 * destination buffer. The p= ages are not pinned. a8df8a89788037 David Howells 2022-09-10 318 */ a8df8a89788037 David Howells 2022-09-10 319 static ssize_t iov_iter_extra= ct_xarray(struct iov_iter *iter, a8df8a89788037 David Howells 2022-09-10 320 void *array, unsig= ned int array_max, a8df8a89788037 David Howells 2022-09-10 321 ssize_t maxsize, a8df8a89788037 David Howells 2022-09-10 322 enum iter_extract_= dest dest) a8df8a89788037 David Howells 2022-09-10 323 { a8df8a89788037 David Howells 2022-09-10 324 struct xarray *xa =3D iter->= xarray; a8df8a89788037 David Howells 2022-09-10 325 struct folio *folio; a8df8a89788037 David Howells 2022-09-10 326 unsigned int ix; a8df8a89788037 David Howells 2022-09-10 327 loff_t start =3D iter->xarra= y_start + iter->iov_offset; a8df8a89788037 David Howells 2022-09-10 328 pgoff_t index =3D start / PA= GE_SIZE; a8df8a89788037 David Howells 2022-09-10 329 ssize_t ret; a8df8a89788037 David Howells 2022-09-10 330 size_t offset, len; a8df8a89788037 David Howells 2022-09-10 331 XA_STATE(xas, xa, index); a8df8a89788037 David Howells 2022-09-10 332 = a8df8a89788037 David Howells 2022-09-10 333 rcu_read_lock(); a8df8a89788037 David Howells 2022-09-10 334 xas_for_each(&xas, folio, UL= ONG_MAX) { a8df8a89788037 David Howells 2022-09-10 335 if (xas_retry(&xas, folio)) a8df8a89788037 David Howells 2022-09-10 336 continue; a8df8a89788037 David Howells 2022-09-10 337 if (WARN_ON(xa_is_value(fol= io))) a8df8a89788037 David Howells 2022-09-10 338 break; a8df8a89788037 David Howells 2022-09-10 339 if (WARN_ON(folio_test_huge= tlb(folio))) a8df8a89788037 David Howells 2022-09-10 340 break; a8df8a89788037 David Howells 2022-09-10 341 = a8df8a89788037 David Howells 2022-09-10 342 offset =3D offset_in_folio(= folio, start); a8df8a89788037 David Howells 2022-09-10 343 len =3D min_t(size_t, maxsi= ze, folio_size(folio) - offset); a8df8a89788037 David Howells 2022-09-10 344 = a8df8a89788037 David Howells 2022-09-10 345 ix =3D extract_contig_pages= (array, folio_page(folio, 0), a8df8a89788037 David Howells 2022-09-10 346 offset, len, dest); a8df8a89788037 David Howells 2022-09-10 347 maxsize -=3D len; a8df8a89788037 David Howells 2022-09-10 @348 ret +=3D len; a8df8a89788037 David Howells 2022-09-10 349 if (ix >=3D array_max) { a8df8a89788037 David Howells 2022-09-10 350 WARN_ON_ONCE(ix > array_ma= x); a8df8a89788037 David Howells 2022-09-10 351 break; a8df8a89788037 David Howells 2022-09-10 352 } a8df8a89788037 David Howells 2022-09-10 353 = a8df8a89788037 David Howells 2022-09-10 354 if (maxsize <=3D 0) a8df8a89788037 David Howells 2022-09-10 355 break; a8df8a89788037 David Howells 2022-09-10 356 } a8df8a89788037 David Howells 2022-09-10 357 = a8df8a89788037 David Howells 2022-09-10 358 rcu_read_unlock(); a8df8a89788037 David Howells 2022-09-10 359 terminate_array(array, dest); a8df8a89788037 David Howells 2022-09-10 360 return ret; a8df8a89788037 David Howells 2022-09-10 361 } a8df8a89788037 David Howells 2022-09-10 362 = -- = 0-DAY CI Kernel Test Service https://01.org/lkp --===============6851076486495107930==--