diff options
Diffstat (limited to 'kernel/mm/mremap.c')
| -rw-r--r-- | kernel/mm/mremap.c | 63 |
1 files changed, 32 insertions, 31 deletions
diff --git a/kernel/mm/mremap.c b/kernel/mm/mremap.c index 034e2d360..c25bc6268 100644 --- 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(¤t->mm->mmap_sem); if (locked && new_len > old_len) mm_populate(new_addr + old_len, new_len - old_len); |