Re: [PATCH next v2 11/11] minmax: min() and max() don't need to return constant expressions

kernel test robot
2024-02-26T10:57:07Z

Hi David,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on linux/master mkl-can-next/testing kdave/for-next akpm-mm/mm-nonmm-unstable linus/master v6.8-rc6]
[cannot apply to next-20240223 dtor-input/next dtor-input/for-linus axboe-block/for-next horms-ipvs/master next-20240223]
[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-Laight/minmax-Put-all-the-clamp-definitions-together/20240226-005902
base: git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link: https://lore.kernel.org/r/a18dcae310f74dcb9c6fc01d5bdc0568%40AcuMS.aculab.com
patch subject: [PATCH next v2 11/11] minmax: min() and max() don't need to return constant expressions
config: i386-randconfig-011-20240226 (https://download.01.org/0day-ci/archive/20240226/202402261802.9ShoXRwY-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240226/202402261802.9ShoXRwY-lkp@intel.com/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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202402261802.9ShoXRwY-lkp@intel.com/

All warnings (new ones prefixed by >>):

arch/x86/mm/pgtable.c: In function 'pgd_alloc':
>> arch/x86/mm/pgtable.c:437:9: warning: ISO C90 forbids variable length array 'pmds' [-Wvla]
437 | pmd_t *pmds[MAX_PREALLOCATED_PMDS];
| ^~~~~

vim +/pmds +437 arch/x86/mm/pgtable.c

1db491f77b6ed0 Fenghua Yu 2015-01-15 432
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 433 pgd_t *pgd_alloc(struct mm_struct *mm)
1ec1fe73dfb711 Ingo Molnar 2008-03-19 434 {
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 435 pgd_t *pgd;
184d47f0fd3651 Kees Cook 2018-10-08 436 pmd_t *u_pmds[MAX_PREALLOCATED_USER_PMDS];
184d47f0fd3651 Kees Cook 2018-10-08 @437 pmd_t *pmds[MAX_PREALLOCATED_PMDS];
1ec1fe73dfb711 Ingo Molnar 2008-03-19 438
1db491f77b6ed0 Fenghua Yu 2015-01-15 439 pgd = _pgd_alloc();
1ec1fe73dfb711 Ingo Molnar 2008-03-19 440
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 441 if (pgd == NULL)
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 442 goto out;
4f76cd382213b2 Jeremy Fitzhardinge 2008-03-17 443
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 444 mm->pgd = pgd;
4f76cd382213b2 Jeremy Fitzhardinge 2008-03-17 445
25226df4b9be7f Gustavo A. R. Silva 2022-09-21 446 if (sizeof(pmds) != 0 &&
25226df4b9be7f Gustavo A. R. Silva 2022-09-21 447 preallocate_pmds(mm, pmds, PREALLOCATED_PMDS) != 0)
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 448 goto out_free_pgd;
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 449
25226df4b9be7f Gustavo A. R. Silva 2022-09-21 450 if (sizeof(u_pmds) != 0 &&
25226df4b9be7f Gustavo A. R. Silva 2022-09-21 451 preallocate_pmds(mm, u_pmds, PREALLOCATED_USER_PMDS) != 0)
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 452 goto out_free_pmds;
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 453
f59dbe9ca6707e Joerg Roedel 2018-07-18 454 if (paravirt_pgd_alloc(mm) != 0)
f59dbe9ca6707e Joerg Roedel 2018-07-18 455 goto out_free_user_pmds;
f59dbe9ca6707e Joerg Roedel 2018-07-18 456
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 457 /*
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 458 * Make sure that pre-populating the pmds is atomic with
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 459 * respect to anything walking the pgd_list, so that they
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 460 * never see a partially populated pgd.
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 461 */
a79e53d85683c6 Andrea Arcangeli 2011-02-16 462 spin_lock(&pgd_lock);
4f76cd382213b2 Jeremy Fitzhardinge 2008-03-17 463
617d34d9e5d832 Jeremy Fitzhardinge 2010-09-21 464 pgd_ctor(mm, pgd);
25226df4b9be7f Gustavo A. R. Silva 2022-09-21 465 if (sizeof(pmds) != 0)
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 466 pgd_prepopulate_pmd(mm, pgd, pmds);
25226df4b9be7f Gustavo A. R. Silva 2022-09-21 467
25226df4b9be7f Gustavo A. R. Silva 2022-09-21 468 if (sizeof(u_pmds) != 0)
f59dbe9ca6707e Joerg Roedel 2018-07-18 469 pgd_prepopulate_user_pmd(mm, pgd, u_pmds);
4f76cd382213b2 Jeremy Fitzhardinge 2008-03-17 470
a79e53d85683c6 Andrea Arcangeli 2011-02-16 471 spin_unlock(&pgd_lock);
4f76cd382213b2 Jeremy Fitzhardinge 2008-03-17 472
4f76cd382213b2 Jeremy Fitzhardinge 2008-03-17 473 return pgd;
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 474
f59dbe9ca6707e Joerg Roedel 2018-07-18 475 out_free_user_pmds:
25226df4b9be7f Gustavo A. R. Silva 2022-09-21 476 if (sizeof(u_pmds) != 0)
f59dbe9ca6707e Joerg Roedel 2018-07-18 477 free_pmds(mm, u_pmds, PREALLOCATED_USER_PMDS);
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 478 out_free_pmds:
25226df4b9be7f Gustavo A. R. Silva 2022-09-21 479 if (sizeof(pmds) != 0)
f59dbe9ca6707e Joerg Roedel 2018-07-18 480 free_pmds(mm, pmds, PREALLOCATED_PMDS);
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 481 out_free_pgd:
1db491f77b6ed0 Fenghua Yu 2015-01-15 482 _pgd_free(pgd);
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 483 out:
d8d5900ef8afc5 Jeremy Fitzhardinge 2008-06-25 484 return NULL;
4f76cd382213b2 Jeremy Fitzhardinge 2008-03-17 485 }
4f76cd382213b2 Jeremy Fitzhardinge 2008-03-17 486

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