diff options
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 45 |
1 files changed, 33 insertions, 12 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index dcdab2675a21..40248d84ad5f 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1030,7 +1030,7 @@ static inline int is_mergeable_anon_vma(struct anon_vma *anon_vma1, * anon_vmas, nor if same anon_vma is assigned but offsets incompatible. * * We don't check here for the merged mmap wrapping around the end of pagecache - * indices (16TB on ia32) because do_mmap_pgoff() does not permit mmap's which + * indices (16TB on ia32) because do_mmap() does not permit mmap's which * wrap, nor mmaps which cover the final page at index -1UL. */ static int @@ -1365,11 +1365,11 @@ static inline bool file_mmap_ok(struct file *file, struct inode *inode, */ unsigned long do_mmap(struct file *file, unsigned long addr, unsigned long len, unsigned long prot, - unsigned long flags, vm_flags_t vm_flags, - unsigned long pgoff, unsigned long *populate, - struct list_head *uf) + unsigned long flags, unsigned long pgoff, + unsigned long *populate, struct list_head *uf) { struct mm_struct *mm = current->mm; + vm_flags_t vm_flags; int pkey = 0; *populate = 0; @@ -1431,7 +1431,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr, * to. we assume access permissions have been handled by the open * of the memory object, so we don't do any here. */ - vm_flags |= calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(flags) | + vm_flags = calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(flags) | mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; if (flags & MAP_LOCKED) @@ -1562,11 +1562,12 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, file = fget(fd); if (!file) return -EBADF; - if (is_file_hugepages(file)) + if (is_file_hugepages(file)) { len = ALIGN(len, huge_page_size(hstate_file(file))); - retval = -EINVAL; - if (unlikely(flags & MAP_HUGETLB && !is_file_hugepages(file))) + } else if (unlikely(flags & MAP_HUGETLB)) { + retval = -EINVAL; goto out_fput; + } } else if (flags & MAP_HUGETLB) { struct user_struct *user = NULL; struct hstate *hs; @@ -1689,7 +1690,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, struct list_head *uf) { struct mm_struct *mm = current->mm; - struct vm_area_struct *vma, *prev; + struct vm_area_struct *vma, *prev, *merge; int error; struct rb_node **rb_link, *rb_parent; unsigned long charged = 0; @@ -1773,6 +1774,25 @@ unsigned long mmap_region(struct file *file, unsigned long addr, if (error) goto unmap_and_free_vma; + /* If vm_flags changed after call_mmap(), we should try merge vma again + * as we may succeed this time. + */ + if (unlikely(vm_flags != vma->vm_flags && prev)) { + merge = vma_merge(mm, prev, vma->vm_start, vma->vm_end, vma->vm_flags, + NULL, vma->vm_file, vma->vm_pgoff, NULL, NULL_VM_UFFD_CTX); + if (merge) { + fput(file); + vm_area_free(vma); + vma = merge; + /* Update vm_flags and possible addr to pick up the change. We don't + * warn here if addr changed as the vma is not linked by vma_link(). + */ + addr = vma->vm_start; + vm_flags = vma->vm_flags; + goto unmap_writable; + } + } + /* Can addr have changed?? * * Answer: Yes, several device drivers can do it in their @@ -1795,6 +1815,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, vma_link(mm, vma, prev, rb_link, rb_parent); /* Once vma denies write, undo our temporary denial count */ if (file) { +unmap_writable: if (vm_flags & VM_SHARED) mapping_unmap_writable(file->f_mapping); if (vm_flags & VM_DENYWRITE) @@ -2209,7 +2230,7 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, /* * mmap_region() will call shmem_zero_setup() to create a file, * so use shmem's get_unmapped_area in case it can be huge. - * do_mmap_pgoff() will clear pgoff, so match alignment. + * do_mmap() will clear pgoff, so match alignment. */ pgoff = 0; get_area = shmem_get_unmapped_area; @@ -2982,7 +3003,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, } file = get_file(vma->vm_file); - ret = do_mmap_pgoff(vma->vm_file, start, size, + ret = do_mmap(vma->vm_file, start, size, prot, flags, pgoff, &populate, NULL); fput(file); out: @@ -3202,7 +3223,7 @@ int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma) * By setting it to reflect the virtual start address of the * vma, merges and splits can happen in a seamless way, just * using the existing file pgoff checks and manipulations. - * Similarly in do_mmap_pgoff and in do_brk. + * Similarly in do_mmap and in do_brk. */ if (vma_is_anonymous(vma)) { BUG_ON(vma->anon_vma); |