Messages in this thread | | | Subject | Re: [PATCH v2 1/3] xen/privcmd: Corrected error handling path | From | Jürgen Groß <> | Date | Tue, 7 Jul 2020 13:45:42 +0200 |
| |
On 07.07.20 13:40, Souptick Joarder wrote: > On Tue, Jul 7, 2020 at 3:05 PM Jürgen Groß <jgross@suse.com> wrote: >> >> On 06.07.20 20:16, Souptick Joarder wrote: >>> Previously, if lock_pages() end up partially mapping pages, it used >>> to return -ERRNO due to which unlock_pages() have to go through >>> each pages[i] till *nr_pages* to validate them. This can be avoided >>> by passing correct number of partially mapped pages & -ERRNO separately, >>> while returning from lock_pages() due to error. >>> >>> With this fix unlock_pages() doesn't need to validate pages[i] till >>> *nr_pages* for error scenario and few condition checks can be ignored. >>> >>> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> >>> Cc: John Hubbard <jhubbard@nvidia.com> >>> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> >>> Cc: Paul Durrant <xadimgnik@gmail.com> >>> --- >>> drivers/xen/privcmd.c | 31 +++++++++++++++---------------- >>> 1 file changed, 15 insertions(+), 16 deletions(-) >>> >>> diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c >>> index a250d11..33677ea 100644 >>> --- a/drivers/xen/privcmd.c >>> +++ b/drivers/xen/privcmd.c >>> @@ -580,13 +580,13 @@ static long privcmd_ioctl_mmap_batch( >>> >>> static int lock_pages( >>> struct privcmd_dm_op_buf kbufs[], unsigned int num, >>> - struct page *pages[], unsigned int nr_pages) >>> + struct page *pages[], unsigned int nr_pages, unsigned int *pinned) >>> { >>> unsigned int i; >>> + int page_count = 0; >> >> Initial value shouldn't be needed, and ... >> >>> >>> for (i = 0; i < num; i++) { >>> unsigned int requested; >>> - int pinned; >> >> ... you could move the declaration here. >> >> With that done you can add my >> >> Reviewed-by: Juergen Gross <jgross@suse.com> > > Ok. But does it going make any difference other than limiting scope ?
Dropping the initializer surely does, and in the end page_count just replaces the former pinned variable, so why would we want to widen the scope with this patch?
Juergen
| |