Commit 490fc053 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 95faf699

arch/ia64/kernel/perfmon.c

+1 −3
Original line number Diff line number Diff line
@@ -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 */

arch/ia64/mm/init.c

+2 −6
Original line number Diff line number Diff line
@@ -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 |

fs/exec.c

+1 −3
Original line number Diff line number Diff line
@@ -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)

include/linux/mm.h

+1 −1
Original line number Diff line number Diff line
@@ -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 *);

kernel/fork.c

+8 −2
Original line number Diff line number Diff line
@@ -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)

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