mm: make vm_area_alloc() initialize core fields

Like vm_area_dup(), it initializes the anon_vma_chain head, and the
basic mm pointer.

The rest of the fields end up being different for different users,
although the plan is to also initialize the 'vm_ops' field to a dummy
entry.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2018-07-21 15:24:03 -07:00
parent 95faf6992d
commit 490fc05386
7 changed files with 17 additions and 26 deletions

View File

@ -2278,17 +2278,15 @@ pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t
DPRINT(("smpl_buf @%p\n", smpl_buf));
/* allocate vma */
vma = vm_area_alloc();
vma = vm_area_alloc(mm);
if (!vma) {
DPRINT(("Cannot allocate vma\n"));
goto error_kmem;
}
INIT_LIST_HEAD(&vma->anon_vma_chain);
/*
* partially initialize the vma for the sampling buffer
*/
vma->vm_mm = mm;
vma->vm_file = get_file(filp);
vma->vm_flags = VM_READ|VM_MAYREAD|VM_DONTEXPAND|VM_DONTDUMP;
vma->vm_page_prot = PAGE_READONLY; /* XXX may need to change */

View File

@ -114,10 +114,8 @@ ia64_init_addr_space (void)
* the problem. When the process attempts to write to the register backing store
* for the first time, it will get a SEGFAULT in this case.
*/
vma = vm_area_alloc();
vma = vm_area_alloc(current->mm);
if (vma) {
INIT_LIST_HEAD(&vma->anon_vma_chain);
vma->vm_mm = current->mm;
vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
vma->vm_end = vma->vm_start + PAGE_SIZE;
vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
@ -133,10 +131,8 @@ ia64_init_addr_space (void)
/* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
if (!(current->personality & MMAP_PAGE_ZERO)) {
vma = vm_area_alloc();
vma = vm_area_alloc(current->mm);
if (vma) {
INIT_LIST_HEAD(&vma->anon_vma_chain);
vma->vm_mm = current->mm;
vma->vm_end = PAGE_SIZE;
vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO |

View File

@ -290,7 +290,7 @@ static int __bprm_mm_init(struct linux_binprm *bprm)
struct vm_area_struct *vma = NULL;
struct mm_struct *mm = bprm->mm;
bprm->vma = vma = vm_area_alloc();
bprm->vma = vma = vm_area_alloc(mm);
if (!vma)
return -ENOMEM;
@ -298,7 +298,6 @@ static int __bprm_mm_init(struct linux_binprm *bprm)
err = -EINTR;
goto err_free;
}
vma->vm_mm = mm;
/*
* Place the stack at the largest stack address the architecture
@ -311,7 +310,6 @@ static int __bprm_mm_init(struct linux_binprm *bprm)
vma->vm_start = vma->vm_end - PAGE_SIZE;
vma->vm_flags = VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP;
vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
INIT_LIST_HEAD(&vma->anon_vma_chain);
err = insert_vm_struct(mm, vma);
if (err)

View File

@ -155,7 +155,7 @@ extern int overcommit_kbytes_handler(struct ctl_table *, int, void __user *,
* mmap() functions).
*/
struct vm_area_struct *vm_area_alloc(void);
struct vm_area_struct *vm_area_alloc(struct mm_struct *);
struct vm_area_struct *vm_area_dup(struct vm_area_struct *);
void vm_area_free(struct vm_area_struct *);

View File

@ -308,9 +308,15 @@ static struct kmem_cache *vm_area_cachep;
/* SLAB cache for mm_struct structures (tsk->mm) */
static struct kmem_cache *mm_cachep;
struct vm_area_struct *vm_area_alloc(void)
struct vm_area_struct *vm_area_alloc(struct mm_struct *mm)
{
return kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
struct vm_area_struct *vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
if (vma) {
vma->vm_mm = mm;
INIT_LIST_HEAD(&vma->anon_vma_chain);
}
return vma;
}
struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig)

View File

@ -1729,19 +1729,17 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
* specific mapper. the address has already been validated, but
* not unmapped, but the maps are removed from the list.
*/
vma = vm_area_alloc();
vma = vm_area_alloc(mm);
if (!vma) {
error = -ENOMEM;
goto unacct_error;
}
vma->vm_mm = mm;
vma->vm_start = addr;
vma->vm_end = addr + len;
vma->vm_flags = vm_flags;
vma->vm_page_prot = vm_get_page_prot(vm_flags);
vma->vm_pgoff = pgoff;
INIT_LIST_HEAD(&vma->anon_vma_chain);
if (file) {
if (vm_flags & VM_DENYWRITE) {
@ -2979,14 +2977,12 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla
/*
* create a vma struct for an anonymous mapping
*/
vma = vm_area_alloc();
vma = vm_area_alloc(mm);
if (!vma) {
vm_unacct_memory(len >> PAGE_SHIFT);
return -ENOMEM;
}
INIT_LIST_HEAD(&vma->anon_vma_chain);
vma->vm_mm = mm;
vma->vm_start = addr;
vma->vm_end = addr + len;
vma->vm_pgoff = pgoff;
@ -3343,12 +3339,10 @@ static struct vm_area_struct *__install_special_mapping(
int ret;
struct vm_area_struct *vma;
vma = vm_area_alloc();
vma = vm_area_alloc(mm);
if (unlikely(vma == NULL))
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&vma->anon_vma_chain);
vma->vm_mm = mm;
vma->vm_start = addr;
vma->vm_end = addr + len;

View File

@ -1204,7 +1204,7 @@ unsigned long do_mmap(struct file *file,
if (!region)
goto error_getting_region;
vma = vm_area_alloc();
vma = vm_area_alloc(current->mm);
if (!vma)
goto error_getting_vma;
@ -1212,7 +1212,6 @@ unsigned long do_mmap(struct file *file,
region->vm_flags = vm_flags;
region->vm_pgoff = pgoff;
INIT_LIST_HEAD(&vma->anon_vma_chain);
vma->vm_flags = vm_flags;
vma->vm_pgoff = pgoff;