| Message ID | 0882a964-770e-418c-9c34-1a64195baafc@moroto.mountain (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] mm/khugepaged: Fix an uninitialized variable bug | expand |
On Fri, 20 Oct 2023 17:14:36 +0300 Dan Carpenter <dan.carpenter@linaro.org> wrote: > This was changed from find_lock_page() which returns NULL to > filemap_lock_folio() which returns error pointers. Update the > error checking to match. > > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -1508,7 +1508,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, > > folio = filemap_lock_folio(vma->vm_file->f_mapping, > linear_page_index(vma, haddr)); > - if (!folio) > + if (IS_ERR(folio)) > return SCAN_PAGE_NULL; > > if (folio_order(folio) != HPAGE_PMD_ORDER) { Also doesn't appear applicable to current kernels?
On Fri, Oct 20, 2023 at 9:36 AM Andrew Morton <akpm@linux-foundation.org> wrote: > > On Fri, 20 Oct 2023 17:14:36 +0300 Dan Carpenter <dan.carpenter@linaro.org> wrote: > > > This was changed from find_lock_page() which returns NULL to > > filemap_lock_folio() which returns error pointers. Update the > > error checking to match. > > > > --- a/mm/khugepaged.c > > +++ b/mm/khugepaged.c > > @@ -1508,7 +1508,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, > > > > folio = filemap_lock_folio(vma->vm_file->f_mapping, > > linear_page_index(vma, haddr)); > > - if (!folio) > > + if (IS_ERR(folio)) > > return SCAN_PAGE_NULL; > > > > if (folio_order(folio) != HPAGE_PMD_ORDER) { > > Also doesn't appear applicable to current kernels? Thanks for these. Both these fix patches address issues introduced by my khugepaged folio conversion patchset: https://lore.kernel.org/linux-mm/20231018203213.50224-1-vishal.moola@gmail.com/T/#t Andrew already dropped the patchset from current kernels so I can fix a couple issues, v3 will include all these fixes.
On Fri, Oct 20, 2023 at 09:49:15AM -0700, Vishal Moola wrote: > On Fri, Oct 20, 2023 at 9:36 AM Andrew Morton <akpm@linux-foundation.org> wrote: > > > > On Fri, 20 Oct 2023 17:14:36 +0300 Dan Carpenter <dan.carpenter@linaro.org> wrote: > > > > > This was changed from find_lock_page() which returns NULL to > > > filemap_lock_folio() which returns error pointers. Update the > > > error checking to match. > > > > > > --- a/mm/khugepaged.c > > > +++ b/mm/khugepaged.c > > > @@ -1508,7 +1508,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, > > > > > > folio = filemap_lock_folio(vma->vm_file->f_mapping, > > > linear_page_index(vma, haddr)); > > > - if (!folio) > > > + if (IS_ERR(folio)) > > > return SCAN_PAGE_NULL; > > > > > > if (folio_order(folio) != HPAGE_PMD_ORDER) { > > > > Also doesn't appear applicable to current kernels? > > Thanks for these. Both these fix patches address issues introduced by my > khugepaged folio conversion patchset: > https://lore.kernel.org/linux-mm/20231018203213.50224-1-vishal.moola@gmail.com/T/#t > > Andrew already dropped the patchset from current kernels so I can fix a > couple issues, v3 will include all these fixes. Only this one was introduced by your patchset. The other bug is older. I don't know why it only showed up as a new bug now. I had guessed that it was other changes I had made to Smatch which affected this. regards, dan carpenter
On Mon, Oct 23, 2023 at 07:59:12AM +0300, Dan Carpenter wrote: > On Fri, Oct 20, 2023 at 09:49:15AM -0700, Vishal Moola wrote: > > On Fri, Oct 20, 2023 at 9:36 AM Andrew Morton <akpm@linux-foundation.org> wrote: > > > > > > On Fri, 20 Oct 2023 17:14:36 +0300 Dan Carpenter <dan.carpenter@linaro.org> wrote: > > > > > > > This was changed from find_lock_page() which returns NULL to > > > > filemap_lock_folio() which returns error pointers. Update the > > > > error checking to match. > > > > > > > > --- a/mm/khugepaged.c > > > > +++ b/mm/khugepaged.c > > > > @@ -1508,7 +1508,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, > > > > > > > > folio = filemap_lock_folio(vma->vm_file->f_mapping, > > > > linear_page_index(vma, haddr)); > > > > - if (!folio) > > > > + if (IS_ERR(folio)) > > > > return SCAN_PAGE_NULL; > > > > > > > > if (folio_order(folio) != HPAGE_PMD_ORDER) { > > > > > > Also doesn't appear applicable to current kernels? > > > > Thanks for these. Both these fix patches address issues introduced by my > > khugepaged folio conversion patchset: > > https://lore.kernel.org/linux-mm/20231018203213.50224-1-vishal.moola@gmail.com/T/#t > > > > Andrew already dropped the patchset from current kernels so I can fix a > > couple issues, v3 will include all these fixes. > > > Only this one was introduced by your patchset. The other bug is older. > I don't know why it only showed up as a new bug now. I had guessed that > it was other changes I had made to Smatch which affected this. Heh. Nope. I was wrong. These were both introduces as part of the folio conversion patchset. Thanks for taking care of this, Vishal. regards, dan carpenter
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index a25f5b7c3e7e..d977eb50704a 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1508,7 +1508,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, folio = filemap_lock_folio(vma->vm_file->f_mapping, linear_page_index(vma, haddr)); - if (!folio) + if (IS_ERR(folio)) return SCAN_PAGE_NULL; if (folio_order(folio) != HPAGE_PMD_ORDER) {
This was changed from find_lock_page() which returns NULL to filemap_lock_folio() which returns error pointers. Update the error checking to match. Fixes: 8f5654d233e3 ("mm/khugepaged: convert collapse_pte_mapped_thp() to use folios") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> --- mm/khugepaged.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)