| Message ID | 20250416202441.3911142-1-alex.williamson@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [stable,6.1] mm: Fix is_zero_page() usage in try_grab_page() | expand |
Hi Alex, On Wed, Apr 16, 2025 at 02:24:39PM -0600, Alex Williamson wrote: > The backport of upstream commit c8070b787519 ("mm: Don't pin ZERO_PAGE > in pin_user_pages()") into v6.1.130 noted below in Fixes does not > account for commit 0f0892356fa1 ("mm: allow multiple error returns in > try_grab_page()"), which changed the return value of try_grab_page() > from bool to int. Therefore returning 0, success in the upstream > version, becomes an error here. Fix the return value. > > Fixes: 476c1dfefab8 ("mm: Don't pin ZERO_PAGE in pin_user_pages()") > Link: https://lore.kernel.org/all/Z_6uhLQjJ7SSzI13@eldamar.lan > Reported-by: Salvatore Bonaccorso <carnil@debian.org> > Reported-by: Milan Broz <gmazyland@gmail.com> > Cc: stable@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: linux-mm@kvack.org > Cc: Sasha Levin <sashal@kernel.org> > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > --- > mm/gup.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/gup.c b/mm/gup.c > index b1daaa9d89aa..76a2b0943e2d 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -232,7 +232,7 @@ bool __must_check try_grab_page(struct page *page, unsigned int flags) > * and it is used in a *lot* of places. > */ > if (is_zero_page(page)) > - return 0; > + return true; > > /* > * Similar to try_grab_folio(): be sure to *also* > -- > 2.48.1 Thank you, with your patch applied one test VM with a PCI passhtrough configuration start again. Tested-by: Salvatore Bonaccorso <carnil@debian.org> Regards, Salvatore
On 16.04.25 22:24, Alex Williamson wrote: > The backport of upstream commit c8070b787519 ("mm: Don't pin ZERO_PAGE > in pin_user_pages()") into v6.1.130 noted below in Fixes does not > account for commit 0f0892356fa1 ("mm: allow multiple error returns in > try_grab_page()"), which changed the return value of try_grab_page() > from bool to int. Therefore returning 0, success in the upstream > version, becomes an error here. Fix the return value. > > Fixes: 476c1dfefab8 ("mm: Don't pin ZERO_PAGE in pin_user_pages()") > Link: https://lore.kernel.org/all/Z_6uhLQjJ7SSzI13@eldamar.lan > Reported-by: Salvatore Bonaccorso <carnil@debian.org> > Reported-by: Milan Broz <gmazyland@gmail.com> > Cc: stable@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: linux-mm@kvack.org > Cc: Sasha Levin <sashal@kernel.org> > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > --- > mm/gup.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/gup.c b/mm/gup.c > index b1daaa9d89aa..76a2b0943e2d 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -232,7 +232,7 @@ bool __must_check try_grab_page(struct page *page, unsigned int flags) > * and it is used in a *lot* of places. > */ > if (is_zero_page(page)) > - return 0; > + return true; > > /* > * Similar to try_grab_folio(): be sure to *also* Reviewed-by: David Hildenbrand <david@redhat.com>
diff --git a/mm/gup.c b/mm/gup.c index b1daaa9d89aa..76a2b0943e2d 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -232,7 +232,7 @@ bool __must_check try_grab_page(struct page *page, unsigned int flags) * and it is used in a *lot* of places. */ if (is_zero_page(page)) - return 0; + return true; /* * Similar to try_grab_folio(): be sure to *also*
The backport of upstream commit c8070b787519 ("mm: Don't pin ZERO_PAGE in pin_user_pages()") into v6.1.130 noted below in Fixes does not account for commit 0f0892356fa1 ("mm: allow multiple error returns in try_grab_page()"), which changed the return value of try_grab_page() from bool to int. Therefore returning 0, success in the upstream version, becomes an error here. Fix the return value. Fixes: 476c1dfefab8 ("mm: Don't pin ZERO_PAGE in pin_user_pages()") Link: https://lore.kernel.org/all/Z_6uhLQjJ7SSzI13@eldamar.lan Reported-by: Salvatore Bonaccorso <carnil@debian.org> Reported-by: Milan Broz <gmazyland@gmail.com> Cc: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Sasha Levin <sashal@kernel.org> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- mm/gup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)