diff options
Diffstat (limited to 'fs/userfaultfd.c')
| -rw-r--r-- | fs/userfaultfd.c | 55 |
1 files changed, 50 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; @@ -1109,6 +1111,17 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, 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. * * FIXME: this shall be relaxed later so that it doesn't fail @@ -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; } @@ -1254,6 +1288,17 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx, 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. * * FIXME: this shall be relaxed later so that it doesn't fail @@ -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 |