| Message ID | 5b20f3cda7cd841555c2626f98d23aa25a039828.1696174961.git.lstoakes@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | various improvements to the GUP interface | expand |
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>
On Sun, Oct 01, 2023 at 05:00:03PM +0100, 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(-) Does gup_test still work? It uses FOLL_TOUCH? Hmm. I guess it was broken for a while anyhow: /* Just the flags we need, copied from mm.h: */ #define FOLL_WRITE 0x01 /* check pte is writable */ #define FOLL_TOUCH 0x02 /* mark page accessed */ Aside from that this seems OK Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Jason
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
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(-)