mm, hugetlbfs: Allow an arch to always use generic versions of get_unmapped_area...

Unlike most architectures, powerpc can only define at runtime
if it is going to use the generic arch_get_unmapped_area() or not.

Today, powerpc has a copy of the generic arch_get_unmapped_area()
because when selection HAVE_ARCH_UNMAPPED_AREA the generic
arch_get_unmapped_area() is not available.

Rename it generic_get_unmapped_area() and make it independent of
HAVE_ARCH_UNMAPPED_AREA.

Do the same for arch_get_unmapped_area_topdown() versus
HAVE_ARCH_UNMAPPED_AREA_TOPDOWN.

Do the same for hugetlb_get_unmapped_area() versus
HAVE_ARCH_HUGETLB_UNMAPPED_AREA.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/77f9d3e592f1c8511df9381aa1c4e754651da4d1.1649523076.git.christophe.leroy@csgroup.eu

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index dd3a088db11d1e9b501f087bb3e87426b666312d..ec611c7de9e32a73f9bf5dd181bc5a3ce2530e92 100644 (file)
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -195,7 +195,6 @@ out:
  * Called under mmap_write_lock(mm).
  */
 
-#ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
 static unsigned long
 hugetlb_get_unmapped_area_bottomup(struct file *file, unsigned long addr,
                unsigned long len, unsigned long pgoff, unsigned long flags)
@@ -244,9 +243,10 @@ hugetlb_get_unmapped_area_topdown(struct file *file, unsigned long addr,
        return addr;
 }
 
-static unsigned long
-hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
-               unsigned long len, unsigned long pgoff, unsigned long flags)
+unsigned long
+generic_hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
+                                 unsigned long len, unsigned long pgoff,
+                                 unsigned long flags)
 {
        struct mm_struct *mm = current->mm;
        struct vm_area_struct *vma;
@@ -283,6 +283,15 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
        return hugetlb_get_unmapped_area_bottomup(file, addr, len,
                        pgoff, flags);
 }
+
+#ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
+static unsigned long
+hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
+                         unsigned long len, unsigned long pgoff,
+                         unsigned long flags)
+{
+       return generic_hugetlb_get_unmapped_area(file, addr, len, pgoff, flags);
+}
 #endif
 
 static size_t

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index ac2a1d758a80eb4177b599f7780bfe4106021db0..bc97c8458df64c05ab5427ddee2f9e5ae1808f7c 100644 (file)
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -519,6 +519,11 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
                                        unsigned long flags);
 #endif /* HAVE_ARCH_HUGETLB_UNMAPPED_AREA */
 
+unsigned long
+generic_hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
+                                 unsigned long len, unsigned long pgoff,
+                                 unsigned long flags);
+
 /*
  * huegtlb page specific state flags.  These flags are located in page.private
  * of the hugetlb head page.  Functions created via the below macros should be

diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 1ad1f4bfa02556554db80ae5a493be3d08ce994e..da3a32d05b34dc9f031fe943c939acd115007cf7 100644 (file)
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -153,6 +153,15 @@ extern unsigned long
 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
                          unsigned long len, unsigned long pgoff,
                          unsigned long flags);
+
+unsigned long
+generic_get_unmapped_area(struct file *filp, unsigned long addr,
+                         unsigned long len, unsigned long pgoff,
+                         unsigned long flags);
+unsigned long
+generic_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
+                                 unsigned long len, unsigned long pgoff,
+                                 unsigned long flags);
 #else
 static inline void arch_pick_mmap_layout(struct mm_struct *mm,
                                         struct rlimit *rlim_stack) {}

diff --git a/mm/mmap.c b/mm/mmap.c
index 313b57d55a634a3df997a3c60bfb6d8a29df41ed..d2b6c3fbfb8c58eafdf84707877a316e0246e40a 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2128,10 +2128,10 @@ unsigned long vm_unmapped_area(struct vm_unmapped_area_info *info)
  *
  * This function "knows" that -ENOMEM has the bits set.
  */
-#ifndef HAVE_ARCH_UNMAPPED_AREA
 unsigned long
-arch_get_unmapped_area(struct file *filp, unsigned long addr,
-               unsigned long len, unsigned long pgoff, unsigned long flags)
+generic_get_unmapped_area(struct file *filp, unsigned long addr,
+                         unsigned long len, unsigned long pgoff,
+                         unsigned long flags)
 {
        struct mm_struct *mm = current->mm;
        struct vm_area_struct *vma, *prev;
@@ -2161,17 +2161,25 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
        info.align_offset = 0;
        return vm_unmapped_area(&info);
 }
+
+#ifndef HAVE_ARCH_UNMAPPED_AREA
+unsigned long
+arch_get_unmapped_area(struct file *filp, unsigned long addr,
+                      unsigned long len, unsigned long pgoff,
+                      unsigned long flags)
+{
+       return generic_get_unmapped_area(filp, addr, len, pgoff, flags);
+}
 #endif
 
 /*
  * This mmap-allocator allocates new areas top-down from below the
  * stack's low limit (the base):
  */
-#ifndef HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 unsigned long
-arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
-                         unsigned long len, unsigned long pgoff,
-                         unsigned long flags)
+generic_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
+                                 unsigned long len, unsigned long pgoff,
+                                 unsigned long flags)
 {
        struct vm_area_struct *vma, *prev;
        struct mm_struct *mm = current->mm;
@@ -2219,6 +2227,15 @@ arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 
        return addr;
 }
+
+#ifndef HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
+unsigned long
+arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
+                              unsigned long len, unsigned long pgoff,
+                              unsigned long flags)
+{
+       return generic_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
+}
 #endif
 
 unsigned long