Messages in this thread | | | Date | Mon, 2 Oct 2023 13:00:23 +0200 | Subject | Re: [PATCH 2/4] mm/gup: explicitly define and check internal GUP flags, disallow FOLL_TOUCH | From | David Hildenbrand <> |
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On 01.10.23 18:00, Lorenzo Stoakes wrote: > Rather than open-coding a list of internal GUP flags in > is_valid_gup_args(), define which ones are internal. > > In addition, we were not explicitly checking to see if the user passed in > FOLL_TOUCH somehow, this patch fixes that. > > Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> > --- > mm/gup.c | 5 ++--- > mm/internal.h | 3 +++ > 2 files changed, 5 insertions(+), 3 deletions(-) > > diff --git a/mm/gup.c b/mm/gup.c > index 2f8a2d89fde1..b21b33d1787e 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -2227,12 +2227,11 @@ static bool is_valid_gup_args(struct page **pages, int *locked, > /* > * These flags not allowed to be specified externally to the gup > * interfaces: > - * - FOLL_PIN/FOLL_TRIED/FOLL_FAST_ONLY are internal only > + * - FOLL_TOUCH/FOLL_PIN/FOLL_TRIED/FOLL_FAST_ONLY are internal only > * - FOLL_REMOTE is internal only and used on follow_page() > * - FOLL_UNLOCKABLE is internal only and used if locked is !NULL > */ > - if (WARN_ON_ONCE(gup_flags & (FOLL_PIN | FOLL_TRIED | FOLL_UNLOCKABLE | > - FOLL_REMOTE | FOLL_FAST_ONLY))) > + if (WARN_ON_ONCE(gup_flags & INTERNAL_GUP_FLAGS)) > return false; > > gup_flags |= to_set; > diff --git a/mm/internal.h b/mm/internal.h > index 449891ad7fdb..499016c6b01d 100644 > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -1018,6 +1018,9 @@ enum { > FOLL_UNLOCKABLE = 1 << 21, > }; > > +#define INTERNAL_GUP_FLAGS (FOLL_TOUCH | FOLL_TRIED | FOLL_REMOTE | FOLL_PIN | \ > + FOLL_FAST_ONLY | FOLL_UNLOCKABLE) > + > /* > * Indicates for which pages that are write-protected in the page table, > * whether GUP has to trigger unsharing via FAULT_FLAG_UNSHARE such that the
Reviewed-by: David Hildenbrand <david@redhat.com>
-- Cheers,
David / dhildenb
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