file ->get_unmapped_area() shouldn't duplicate work of get_unmapped_area()

... we should call mm ->get_unmapped_area() instead and let our caller
do the final checks.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 24 insertions, 17 deletions

diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index ddda12fcbac2..d498b32c75f6 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -317,10 +317,14 @@ bottomup:
 unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags)
 {
         unsigned long align_goal, addr = -ENOMEM;
+        unsigned long (*get_area)(struct file *, unsigned long,
+                                  unsigned long, unsigned long, unsigned long);
+
+        get_area = current->mm->get_unmapped_area;
 
         if (flags & MAP_FIXED) {
                 /* Ok, don't mess with it. */
-                return get_unmapped_area(NULL, orig_addr, len, pgoff, flags);
+                return get_area(NULL, orig_addr, len, pgoff, flags);
         }
         flags &= ~MAP_SHARED;
 
@@ -333,7 +337,7 @@ unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, u
                 align_goal = (64UL * 1024);
 
         do {
-                addr = get_unmapped_area(NULL, orig_addr, len + (align_goal - PAGE_SIZE), pgoff, flags);
+                addr = get_area(NULL, orig_addr, len + (align_goal - PAGE_SIZE), pgoff, flags);
                 if (!(addr & ~PAGE_MASK)) {
                         addr = (addr + (align_goal - 1UL)) & ~(align_goal - 1UL);
                         break;
@@ -351,7 +355,7 @@ unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, u
          * be obtained.
          */
         if (addr & ~PAGE_MASK)
-                addr = get_unmapped_area(NULL, orig_addr, len, pgoff, flags);
+                addr = get_area(NULL, orig_addr, len, pgoff, flags);
 
         return addr;
 }
diff --git a/ipc/shm.c b/ipc/shm.c
index 464694e0aa4a..11bec626c228 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -290,28 +290,28 @@ static unsigned long shm_get_unmapped_area(struct file *file,
         unsigned long flags)
 {
         struct shm_file_data *sfd = shm_file_data(file);
-        return get_unmapped_area(sfd->file, addr, len, pgoff, flags);
-}
-
-int is_file_shm_hugepages(struct file *file)
-{
-        int ret = 0;
-
-        if (file->f_op == &shm_file_operations) {
-                struct shm_file_data *sfd;
-                sfd = shm_file_data(file);
-                ret = is_file_hugepages(sfd->file);
-        }
-        return ret;
+        return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
+                                                pgoff, flags);
 }
 
 static const struct file_operations shm_file_operations = {
         .mmap           = shm_mmap,
         .fsync          = shm_fsync,
         .release        = shm_release,
+};
+
+static const struct file_operations shm_file_operations_huge = {
+        .mmap           = shm_mmap,
+        .fsync          = shm_fsync,
+        .release        = shm_release,
         .get_unmapped_area      = shm_get_unmapped_area,
 };
 
+int is_file_shm_hugepages(struct file *file)
+{
+        return file->f_op == &shm_file_operations_huge;
+}
+
 static const struct vm_operations_struct shm_vm_ops = {
         .open   = shm_open,     /* callback for a new vm-area open */
         .close  = shm_close,    /* callback for when the vm-area is released */
@@ -889,7 +889,10 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
         if (!sfd)
                 goto out_put_dentry;
 
-        file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations);
+        file = alloc_file(path.mnt, path.dentry, f_mode,
+                        is_file_hugepages(shp->shm_file) ?
+                                &shm_file_operations_huge :
+                                &shm_file_operations);
         if (!file)
                 goto out_free;
         ima_counts_get(file);