[PATCH 60/64] drivers/xen: use mm locking wrappers

From: Davidlohr Bueso
Date: Sun Feb 04 2018 - 20:34:00 EST


From: Davidlohr Bueso <dave@xxxxxxxxxxxx>

All callers use mmap_sem within the same function
context. No change in semantics.

Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>
---
drivers/xen/gntdev.c | 5 +++--
drivers/xen/privcmd.c | 12 +++++++-----
2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index bd56653b9bbc..9181eee4e160 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -648,12 +648,13 @@ static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
struct vm_area_struct *vma;
struct grant_map *map;
int rv = -EINVAL;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

if (copy_from_user(&op, u, sizeof(op)) != 0)
return -EFAULT;
pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr);

- down_read(&current->mm->mmap_sem);
+ mm_read_lock(current->mm, &mmrange);
vma = find_vma(current->mm, op.vaddr);
if (!vma || vma->vm_ops != &gntdev_vmops)
goto out_unlock;
@@ -667,7 +668,7 @@ static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
rv = 0;

out_unlock:
- up_read(&current->mm->mmap_sem);
+ mm_read_unlock(current->mm, &mmrange);

if (rv == 0 && copy_to_user(u, &op, sizeof(op)) != 0)
return -EFAULT;
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 1c909183c42a..3736752556c5 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -257,6 +257,7 @@ static long privcmd_ioctl_mmap(struct file *file, void __user *udata)
int rc;
LIST_HEAD(pagelist);
struct mmap_gfn_state state;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

/* We only support privcmd_ioctl_mmap_batch for auto translated. */
if (xen_feature(XENFEAT_auto_translated_physmap))
@@ -276,7 +277,7 @@ static long privcmd_ioctl_mmap(struct file *file, void __user *udata)
if (rc || list_empty(&pagelist))
goto out;

- down_write(&mm->mmap_sem);
+ mm_write_lock(mm, &mmrange);

{
struct page *page = list_first_entry(&pagelist,
@@ -301,7 +302,7 @@ static long privcmd_ioctl_mmap(struct file *file, void __user *udata)


out_up:
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);

out:
free_page_list(&pagelist);
@@ -451,6 +452,7 @@ static long privcmd_ioctl_mmap_batch(
unsigned long nr_pages;
LIST_HEAD(pagelist);
struct mmap_batch_state state;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

switch (version) {
case 1:
@@ -497,7 +499,7 @@ static long privcmd_ioctl_mmap_batch(
}
}

- down_write(&mm->mmap_sem);
+ mm_write_lock(mm, &mmrange);

vma = find_vma(mm, m.addr);
if (!vma ||
@@ -553,7 +555,7 @@ static long privcmd_ioctl_mmap_batch(
BUG_ON(traverse_pages_block(m.num, sizeof(xen_pfn_t),
&pagelist, mmap_batch_fn, &state));

- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);

if (state.global_error) {
/* Write back errors in second pass. */
@@ -574,7 +576,7 @@ static long privcmd_ioctl_mmap_batch(
return ret;

out_unlock:
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
goto out;
}

--
2.13.6