These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / mm / mremap.c

diff --git a/kernel/mm/mremap.c b/kernel/mm/mremap.c
index 034e2d3..c25bc62 100644 (file)
--- a/kernel/mm/mremap.c
+++ b/kernel/mm/mremap.c
@@ -22,6 +22,7 @@
 #include <linux/mmu_notifier.h>
 #include <linux/sched/sysctl.h>
 #include <linux/uaccess.h>
+#include <linux/mm-arch-hooks.h>
 
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
@@ -275,6 +276,12 @@ static unsigned long move_vma(struct vm_area_struct *vma,
        moved_len = move_page_tables(vma, old_addr, new_vma, new_addr, old_len,
                                     need_rmap_locks);
        if (moved_len < old_len) {
+               err = -ENOMEM;
+       } else if (vma->vm_ops && vma->vm_ops->mremap) {
+               err = vma->vm_ops->mremap(new_vma);
+       }
+
+       if (unlikely(err)) {
                /*
                 * On error, move entries back from new area to old,
                 * which will succeed since page tables still there,
@@ -285,14 +292,10 @@ static unsigned long move_vma(struct vm_area_struct *vma,
                vma = new_vma;
                old_len = new_len;
                old_addr = new_addr;
-               new_addr = -ENOMEM;
-       } else if (vma->vm_file && vma->vm_file->f_op->mremap) {
-               err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
-               if (err < 0) {
-                       move_page_tables(new_vma, new_addr, vma, old_addr,
-                                        moved_len, true);
-                       return err;
-               }
+               new_addr = err;
+       } else {
+               arch_remap(mm, old_addr, old_addr + old_len,
+                          new_addr, new_addr + new_len);
        }
 
        /* Conceal VM_ACCOUNT so old reservation is not undone */
@@ -343,6 +346,7 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr,
 {
        struct mm_struct *mm = current->mm;
        struct vm_area_struct *vma = find_vma(mm, addr);
+       unsigned long pgoff;
 
        if (!vma || vma->vm_start > addr)
                return ERR_PTR(-EFAULT);
@@ -354,17 +358,17 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr,
        if (old_len > vma->vm_end - addr)
                return ERR_PTR(-EFAULT);
 
+       if (new_len == old_len)
+               return vma;
+
        /* Need to be careful about a growing mapping */
-       if (new_len > old_len) {
-               unsigned long pgoff;
-
-               if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP))
-                       return ERR_PTR(-EFAULT);
-               pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;
-               pgoff += vma->vm_pgoff;
-               if (pgoff + (new_len >> PAGE_SHIFT) < pgoff)
-                       return ERR_PTR(-EINVAL);
-       }
+       pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;
+       pgoff += vma->vm_pgoff;
+       if (pgoff + (new_len >> PAGE_SHIFT) < pgoff)
+               return ERR_PTR(-EINVAL);
+
+       if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP))
+               return ERR_PTR(-EFAULT);
 
        if (vma->vm_flags & VM_LOCKED) {
                unsigned long locked, lock_limit;
@@ -397,19 +401,14 @@ static unsigned long mremap_to(unsigned long addr, unsigned long old_len,
        unsigned long charged = 0;
        unsigned long map_flags;
 
-       if (new_addr & ~PAGE_MASK)
+       if (offset_in_page(new_addr))
                goto out;
 
        if (new_len > TASK_SIZE || new_addr > TASK_SIZE - new_len)
                goto out;
 
-       /* Check if the location we're moving into overlaps the
-        * old location at all, and fail if it does.
-        */
-       if ((new_addr <= addr) && (new_addr+new_len) > addr)
-               goto out;
-
-       if ((addr <= new_addr) && (addr+old_len) > new_addr)
+       /* Ensure the old/new locations do not overlap */
+       if (addr + old_len > new_addr && new_addr + new_len > addr)
                goto out;
 
        ret = do_munmap(mm, new_addr, new_len);
@@ -436,11 +435,11 @@ static unsigned long mremap_to(unsigned long addr, unsigned long old_len,
        ret = get_unmapped_area(vma->vm_file, new_addr, new_len, vma->vm_pgoff +
                                ((addr - vma->vm_start) >> PAGE_SHIFT),
                                map_flags);
-       if (ret & ~PAGE_MASK)
+       if (offset_in_page(ret))
                goto out1;
 
        ret = move_vma(vma, addr, old_len, new_len, new_addr, locked);
-       if (!(ret & ~PAGE_MASK))
+       if (!(offset_in_page(ret)))
                goto out;
 out1:
        vm_unacct_memory(charged);
@@ -485,7 +484,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
        if (flags & MREMAP_FIXED && !(flags & MREMAP_MAYMOVE))
                return ret;
 
-       if (addr & ~PAGE_MASK)
+       if (offset_in_page(addr))
                return ret;
 
        old_len = PAGE_ALIGN(old_len);
@@ -567,7 +566,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
                                        vma->vm_pgoff +
                                        ((addr - vma->vm_start) >> PAGE_SHIFT),
                                        map_flags);
-               if (new_addr & ~PAGE_MASK) {
+               if (offset_in_page(new_addr)) {
                        ret = new_addr;
                        goto out;
                }
@@ -575,8 +574,10 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
                ret = move_vma(vma, addr, old_len, new_len, new_addr, &locked);
        }
 out:
-       if (ret & ~PAGE_MASK)
+       if (offset_in_page(ret)) {
                vm_unacct_memory(charged);
+               locked = 0;
+       }
        up_write(&current->mm->mmap_sem);
        if (locked && new_len > old_len)
                mm_populate(new_addr + old_len, new_len - old_len);