* Vlastimil Babka <vbabka@xxxxxxx> [220112 11:01]: > On 12/1/21 15:29, Liam Howlett wrote: > > From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx> > > > > vma_lookup() walks the VMA tree for a specific value, find_vma() will > > search the tree after walking to a specific value. It is more efficient > > to only walk to the requested value as this case requires the address to > > equal the vm_start. > > By that you mean the privcmd_ioctl_mmap() code checks msg->va != > vma->vm_start and thus we know it's never interested the next vma, that > find_vma() can return if no vma covers the address? Yes. I will reword the commit message. > > > Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> > > Acked-by: Vlastimil Babka <vbabka@xxxxxxx> > > > --- > > drivers/xen/privcmd.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c > > index 3369734108af..ad17166b0ef6 100644 > > --- a/drivers/xen/privcmd.c > > +++ b/drivers/xen/privcmd.c > > @@ -282,7 +282,7 @@ static long privcmd_ioctl_mmap(struct file *file, void __user *udata) > > struct page, lru); > > struct privcmd_mmap_entry *msg = page_address(page); > > > > - vma = find_vma(mm, msg->va); > > + vma = vma_lookup(mm, msg->va); > > rc = -EINVAL; > > > > if (!vma || (msg->va != vma->vm_start) || vma->vm_private_data) >
