author: Mike Kravetz <mike.kravetz@oracle.com> 2017-02-22 15:43:04 -0800
committer: Linus Torvalds <torvalds@linux-foundation.org> 2017-02-22 16:41:28 -0800
commit: cab350afcbc9c8a744e0d164d1c26560568f770b
parent: 1a1aad8a9b7bd34f60cdf98cd7915f00ae892c45
Commit Summary:
Diffstat:
1 file changed, 46 insertions, 5 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 26e1ef00b63c..5139d05f80e6 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -27,6 +27,7 @@
#include <linux/mempolicy.h>
#include <linux/ioctl.h>
#include <linux/security.h>
+#include <linux/hugetlb.h>
static struct kmem_cache *userfaultfd_ctx_cachep __read_mostly;
@@ -1058,6 +1059,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
struct uffdio_register __user *user_uffdio_register;
unsigned long vm_flags, new_flags;
bool found;
+ bool huge_pages;
unsigned long start, end, vma_end;
user_uffdio_register = (struct uffdio_register __user *) arg;
@@ -1108,6 +1110,17 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
if (vma->vm_start >= end)
goto out_unlock;
+ /*
+ * If the first vma contains huge pages, make sure start address
+ * is aligned to huge page size.
+ */
+ if (is_vm_hugetlb_page(vma)) {
+ unsigned long vma_hpagesize = vma_kernel_pagesize(vma);
+
+ if (start & (vma_hpagesize - 1))
+ goto out_unlock;
+ }
+
/*
* Search for not compatible vmas.
*
@@ -1116,6 +1129,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
* on anonymous vmas).
*/
found = false;
+ huge_pages = false;
for (cur = vma; cur && cur->vm_start < end; cur = cur->vm_next) {
cond_resched();
@@ -1124,8 +1138,21 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
/* check not compatible vmas */
ret = -EINVAL;
- if (!vma_is_anonymous(cur))
+ if (!vma_is_anonymous(cur) && !is_vm_hugetlb_page(cur))
goto out_unlock;
+ /*
+ * If this vma contains ending address, and huge pages
+ * check alignment.
+ */
+ if (is_vm_hugetlb_page(cur) && end <= cur->vm_end &&
+ end > cur->vm_start) {
+ unsigned long vma_hpagesize = vma_kernel_pagesize(cur);
+
+ ret = -EINVAL;
+
+ if (end & (vma_hpagesize - 1))
+ goto out_unlock;
+ }
/*
* Check that this vma isn't already owned by a
@@ -1138,6 +1165,12 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
cur->vm_userfaultfd_ctx.ctx != ctx)
goto out_unlock;
+ /*
+ * Note vmas containing huge pages
+ */
+ if (is_vm_hugetlb_page(cur))
+ huge_pages = true;
+
found = true;
}
BUG_ON(!found);
@@ -1149,7 +1182,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
do {
cond_resched();
- BUG_ON(!vma_is_anonymous(vma));
+ BUG_ON(!vma_is_anonymous(vma) && !is_vm_hugetlb_page(vma));
BUG_ON(vma->vm_userfaultfd_ctx.ctx &&
vma->vm_userfaultfd_ctx.ctx != ctx);
@@ -1207,7 +1240,8 @@ out_unlock:
* userland which ioctls methods are guaranteed to
* succeed on this range.
*/
- if (put_user(UFFD_API_RANGE_IOCTLS,
+ if (put_user(huge_pages ? UFFD_API_RANGE_IOCTLS_HPAGE :
+ UFFD_API_RANGE_IOCTLS,
&user_uffdio_register->ioctls))
ret = -EFAULT;
}
@@ -1253,6 +1287,17 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
if (vma->vm_start >= end)
goto out_unlock;
+ /*
+ * If the first vma contains huge pages, make sure start address
+ * is aligned to huge page size.
+ */
+ if (is_vm_hugetlb_page(vma)) {
+ unsigned long vma_hpagesize = vma_kernel_pagesize(vma);
+
+ if (start & (vma_hpagesize - 1))
+ goto out_unlock;
+ }
+
/*
* Search for not compatible vmas.
*
@@ -1275,7 +1320,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
* provides for more strict behavior to notice
* unregistration errors.
*/
- if (!vma_is_anonymous(cur))
+ if (!vma_is_anonymous(cur) && !is_vm_hugetlb_page(cur))
goto out_unlock;
found = true;
@@ -1289,7 +1334,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
do {
cond_resched();
- BUG_ON(!vma_is_anonymous(vma));
+ BUG_ON(!vma_is_anonymous(vma) && !is_vm_hugetlb_page(vma));
/*
* Nothing to do: this vma is already registered into this