On Wed, Jul 13, 2022 at 7:24 AM Zach O'Keefe <zokeefe@xxxxxxxxxx> wrote: > > On Jul 12 10:02, Yang Shi wrote: > > On Tue, Jul 12, 2022 at 5:36 AM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > > > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-unstable > > > head: 0e9f775fb0b4adf1a4ef50ea156ead09a0fc5194 > > > commit: 9f626ffb1d1c5c26b4a8e0fdffec784a5f773274 [284/293] mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse > > > config: i386-randconfig-m021 (https://download.01.org/0day-ci/archive/20220710/202207100715.TBIYQ4fc-lkp@xxxxxxxxx/config) > > > compiler: gcc-11 (Debian 11.3.0-3) 11.3.0 > > > > > > If you fix the issue, kindly add following tag where applicable > > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > > > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > > > > > > smatch warnings: > > > mm/khugepaged.c:2409 madvise_collapse() warn: possible memory leak of 'cc' > > > > > > vim +/cc +2409 mm/khugepaged.c > > > > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2387 int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev, > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2388 unsigned long start, unsigned long end) > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2389 { > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2390 struct collapse_control *cc; > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2391 struct mm_struct *mm = vma->vm_mm; > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2392 unsigned long hstart, hend, addr; > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2393 int thps = 0, last_fail = SCAN_FAIL; > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2394 bool mmap_locked = true; > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2395 > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2396 BUG_ON(vma->vm_start > start); > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2397 BUG_ON(vma->vm_end < end); > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2398 > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2399 cc = kmalloc(sizeof(*cc), GFP_KERNEL); > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2400 if (!cc) > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2401 return -ENOMEM; > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2402 cc->is_khugepaged = false; > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2403 cc->last_target_node = NUMA_NO_NODE; > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2404 > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2405 *prev = vma; > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2406 > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2407 /* TODO: Support file/shmem */ > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 2408 if (!vma->anon_vma || !vma_is_anonymous(vma)) > > > 9f626ffb1d1c5c Zach O'Keefe 2022-07-06 @2409 return -EINVAL; > > > > It seems better to move the cc kmalloc after the anonymous vma check? > > > > Agreed - something I only noticed when fixing this. I've cleaned up some > ordering here, now looks like: > > ---8<--- > BUG_ON(vma->vm_start > start); > BUG_ON(vma->vm_end < end); > > *prev = vma; > > /* TODO: Support file/shmem */ > if (!vma->anon_vma || !vma_is_anonymous(vma)) > return -EINVAL; > > if (!hugepage_vma_check(vma, vma->vm_flags, false, false, false)) > return -EINVAL; > > cc = kmalloc(sizeof(*cc), GFP_KERNEL); > if (!cc) > return -ENOMEM; > cc->is_khugepaged = false; > cc->last_target_node = NUMA_NO_NODE; > > mmgrab(mm); > lru_add_drain_all(); > > hstart = (start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK; > hend = end & HPAGE_PMD_MASK; > > for (addr = hstart; addr < hend; addr += HPAGE_PMD_SIZE) { > ---8<--- > out_nolock: > mmap_assert_locked(mm); > mmdrop(mm); > kfree(cc); > ---8<--- Looks good to me. > > > > > > > kfree(cc);? > > > > > > > > > -- > > > 0-DAY CI Kernel Test Service > > > https://01.org/lkp > > > > > >
