diff options
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 119 |
1 files changed, 65 insertions, 54 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index aee5fa08ae5d..79d541f1502b 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1358,20 +1358,18 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, return do_vmi_munmap(&vmi, mm, start, len, uf, false); } -unsigned long mmap_region(struct file *file, unsigned long addr, +static unsigned long __mmap_region(struct file *file, unsigned long addr, unsigned long len, vm_flags_t vm_flags, unsigned long pgoff, struct list_head *uf) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma = NULL; pgoff_t pglen = PHYS_PFN(len); - struct vm_area_struct *merge; unsigned long charged = 0; struct vma_munmap_struct vms; struct ma_state mas_detach; struct maple_tree mt_detach; unsigned long end = addr + len; - bool writable_file_mapping = false; int error; VMA_ITERATOR(vmi, mm, addr); VMG_STATE(vmg, mm, &vmi, addr, end, vm_flags, pgoff); @@ -1445,28 +1443,26 @@ unsigned long mmap_region(struct file *file, unsigned long addr, vm_flags_init(vma, vm_flags); vma->vm_page_prot = vm_get_page_prot(vm_flags); + if (vma_iter_prealloc(&vmi, vma)) { + error = -ENOMEM; + goto free_vma; + } + if (file) { vma->vm_file = get_file(file); error = mmap_file(file, vma); if (error) - goto unmap_and_free_vma; - - if (vma_is_shared_maywrite(vma)) { - error = mapping_map_writable(file->f_mapping); - if (error) - goto close_and_free_vma; - - writable_file_mapping = true; - } + goto unmap_and_free_file_vma; + /* Drivers cannot alter the address of the VMA. */ + WARN_ON_ONCE(addr != vma->vm_start); /* - * Expansion is handled above, merging is handled below. - * Drivers should not alter the address of the VMA. + * Drivers should not permit writability when previously it was + * disallowed. */ - if (WARN_ON((addr != vma->vm_start))) { - error = -EINVAL; - goto close_and_free_vma; - } + VM_WARN_ON_ONCE(vm_flags != vma->vm_flags && + !(vm_flags & VM_MAYWRITE) && + (vma->vm_flags & VM_MAYWRITE)); vma_iter_config(&vmi, addr, end); /* @@ -1474,6 +1470,8 @@ unsigned long mmap_region(struct file *file, unsigned long addr, * vma again as we may succeed this time. */ if (unlikely(vm_flags != vma->vm_flags && vmg.prev)) { + struct vm_area_struct *merge; + vmg.flags = vma->vm_flags; /* If this fails, state is reset ready for a reattempt. */ merge = vma_merge_new_range(&vmg); @@ -1491,7 +1489,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, vma = merge; /* Update vm_flags to pick up the change. */ vm_flags = vma->vm_flags; - goto unmap_writable; + goto file_expanded; } vma_iter_config(&vmi, addr, end); } @@ -1500,26 +1498,15 @@ unsigned long mmap_region(struct file *file, unsigned long addr, } else if (vm_flags & VM_SHARED) { error = shmem_zero_setup(vma); if (error) - goto free_vma; + goto free_iter_vma; } else { vma_set_anonymous(vma); } - if (map_deny_write_exec(vma->vm_flags, vma->vm_flags)) { - error = -EACCES; - goto close_and_free_vma; - } - - /* Allow architectures to sanity-check the vm_flags */ - if (!arch_validate_flags(vma->vm_flags)) { - error = -EINVAL; - goto close_and_free_vma; - } - - if (vma_iter_prealloc(&vmi, vma)) { - error = -ENOMEM; - goto close_and_free_vma; - } +#ifdef CONFIG_SPARC64 + /* TODO: Fix SPARC ADI! */ + WARN_ON_ONCE(!arch_validate_flags(vm_flags)); +#endif /* Lock the VMA since it is modified after insertion into VMA tree */ vma_start_write(vma); @@ -1533,10 +1520,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, */ khugepaged_enter_vma(vma, vma->vm_flags); - /* Once vma denies write, undo our temporary denial count */ -unmap_writable: - if (writable_file_mapping) - mapping_unmap_writable(file->f_mapping); +file_expanded: file = vma->vm_file; ksm_add_vma(vma); expanded: @@ -1569,23 +1553,17 @@ expanded: vma_set_page_prot(vma); - validate_mm(mm); return addr; -close_and_free_vma: - vma_close(vma); - - if (file || vma->vm_file) { -unmap_and_free_vma: - fput(vma->vm_file); - vma->vm_file = NULL; +unmap_and_free_file_vma: + fput(vma->vm_file); + vma->vm_file = NULL; - vma_iter_set(&vmi, vma->vm_end); - /* Undo any partial mapping done by a device driver. */ - unmap_region(&vmi.mas, vma, vmg.prev, vmg.next); - } - if (writable_file_mapping) - mapping_unmap_writable(file->f_mapping); + vma_iter_set(&vmi, vma->vm_end); + /* Undo any partial mapping done by a device driver. */ + unmap_region(&vmi.mas, vma, vmg.prev, vmg.next); +free_iter_vma: + vma_iter_free(&vmi); free_vma: vm_area_free(vma); unacct_error: @@ -1595,10 +1573,43 @@ unacct_error: abort_munmap: vms_abort_munmap_vmas(&vms, &mas_detach); gather_failed: - validate_mm(mm); return error; } +unsigned long mmap_region(struct file *file, unsigned long addr, + unsigned long len, vm_flags_t vm_flags, unsigned long pgoff, + struct list_head *uf) +{ + unsigned long ret; + bool writable_file_mapping = false; + + /* Check to see if MDWE is applicable. */ + if (map_deny_write_exec(vm_flags, vm_flags)) + return -EACCES; + + /* Allow architectures to sanity-check the vm_flags. */ + if (!arch_validate_flags(vm_flags)) + return -EINVAL; + + /* Map writable and ensure this isn't a sealed memfd. */ + if (file && is_shared_maywrite(vm_flags)) { + int error = mapping_map_writable(file->f_mapping); + + if (error) + return error; + writable_file_mapping = true; + } + + ret = __mmap_region(file, addr, len, vm_flags, pgoff, uf); + + /* Clear our write mapping regardless of error. */ + if (writable_file_mapping) + mapping_unmap_writable(file->f_mapping); + + validate_mm(current->mm); + return ret; +} + static int __vm_munmap(unsigned long start, size_t len, bool unlock) { int ret; |