Re: [PATCH v16 04/16] mm: untag user pointers in do_pages_move
On Tue, Jun 11, 2019 at 10:18 PM Khalid Aziz wrote: > > On 6/3/19 10:55 AM, Andrey Konovalov wrote: > > This patch is a part of a series that extends arm64 kernel ABI to allow to > > pass tagged user pointers (with the top byte set to something else other > > than 0x00) as syscall arguments. > > > > do_pages_move() is used in the implementation of the move_pages syscall. > > > > Untag user pointers in this function. > > > > Reviewed-by: Catalin Marinas > > Signed-off-by: Andrey Konovalov > > --- > > mm/migrate.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/mm/migrate.c b/mm/migrate.c > > index f2ecc2855a12..3930bb6fa656 100644 > > --- a/mm/migrate.c > > +++ b/mm/migrate.c > > @@ -1617,6 +1617,7 @@ static int do_pages_move(struct mm_struct *mm, > > nodemask_t task_nodes, > > if (get_user(node, nodes + i)) > > goto out_flush; > > addr = (unsigned long)p; > > + addr = untagged_addr(addr); > > Why not just "addr = (unsigned long)untagged_addr(p);" Will do in the next version. I think I'll also merge this commit into the "untag user pointers passed to memory syscalls" one. > > -- > Khalid >
Re: [PATCH v16 04/16] mm: untag user pointers in do_pages_move
On 6/3/19 10:55 AM, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 kernel ABI to allow to > pass tagged user pointers (with the top byte set to something else other > than 0x00) as syscall arguments. > > do_pages_move() is used in the implementation of the move_pages syscall. > > Untag user pointers in this function. > > Reviewed-by: Catalin Marinas > Signed-off-by: Andrey Konovalov > --- > mm/migrate.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/migrate.c b/mm/migrate.c > index f2ecc2855a12..3930bb6fa656 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1617,6 +1617,7 @@ static int do_pages_move(struct mm_struct *mm, > nodemask_t task_nodes, > if (get_user(node, nodes + i)) > goto out_flush; > addr = (unsigned long)p; > + addr = untagged_addr(addr); Why not just "addr = (unsigned long)untagged_addr(p);" -- Khalid
Re: [PATCH v16 04/16] mm: untag user pointers in do_pages_move
On Mon, Jun 03, 2019 at 06:55:06PM +0200, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 kernel ABI to allow to > pass tagged user pointers (with the top byte set to something else other > than 0x00) as syscall arguments. > > do_pages_move() is used in the implementation of the move_pages syscall. > > Untag user pointers in this function. > > Reviewed-by: Catalin Marinas > Signed-off-by: Andrey Konovalov Reviewed-by: Kees Cook -Kees > --- > mm/migrate.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/migrate.c b/mm/migrate.c > index f2ecc2855a12..3930bb6fa656 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1617,6 +1617,7 @@ static int do_pages_move(struct mm_struct *mm, > nodemask_t task_nodes, > if (get_user(node, nodes + i)) > goto out_flush; > addr = (unsigned long)p; > + addr = untagged_addr(addr); > > err = -ENODEV; > if (node < 0 || node >= MAX_NUMNODES) > -- > 2.22.0.rc1.311.g5d7573a151-goog > -- Kees Cook
[PATCH v16 04/16] mm: untag user pointers in do_pages_move
This patch is a part of a series that extends arm64 kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments. do_pages_move() is used in the implementation of the move_pages syscall. Untag user pointers in this function. Reviewed-by: Catalin Marinas Signed-off-by: Andrey Konovalov --- mm/migrate.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/migrate.c b/mm/migrate.c index f2ecc2855a12..3930bb6fa656 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1617,6 +1617,7 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, if (get_user(node, nodes + i)) goto out_flush; addr = (unsigned long)p; + addr = untagged_addr(addr); err = -ENODEV; if (node < 0 || node >= MAX_NUMNODES) -- 2.22.0.rc1.311.g5d7573a151-goog
