| Message ID | e410843d00a4ecd7e525a7a949e605ffc6c394c4.1559580831.git.andreyknvl@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: untag user pointers passed to the kernel | expand |
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 <catalin.marinas@arm.com> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> -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 >
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 <catalin.marinas@arm.com> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> > --- > 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
On Tue, Jun 11, 2019 at 10:18 PM Khalid Aziz <khalid.aziz@oracle.com> 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 <catalin.marinas@arm.com> > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> > > --- > > 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 >
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)