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

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Date:   Mon,  5 Feb 2018 02:27:50 +0100
From:   Davidlohr Bueso <dbueso@...e.de>
To:     akpm@...ux-foundation.org, mingo@...nel.org
Cc:     peterz@...radead.org, ldufour@...ux.vnet.ibm.com, jack@...e.cz,
        mhocko@...nel.org, kirill.shutemov@...ux.intel.com,
        mawilcox@...rosoft.com, mgorman@...hsingularity.net,
        dave@...olabs.net, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, Davidlohr Bueso <dbueso@...e.de>
Subject: [PATCH 60/64] drivers/xen: use mm locking wrappers

From: Davidlohr Bueso <dave@...olabs.net>

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

Signed-off-by: Davidlohr Bueso <dbueso@...e.de>
---
 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