mm: use helper functions for allocating and freeing vm_area structs

The vm_area_struct is one of the most fundamental memory management
objects, but the management of it is entirely open-coded evertwhere,
ranging from allocation and freeing (using kmem_cache_[z]alloc and
kmem_cache_free) to initializing all the fields.

We want to unify this in order to end up having some unified
initialization of the vmas, and the first step to this is to at least
have basic allocation functions.

Right now those functions are literally just wrappers around the
kmem_cache_*() calls.  This is a purely mechanical conversion:

    # new vma:
    kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL) -> vm_area_alloc()

    # copy old vma
    kmem_cache_alloc(vm_area_cachep, GFP_KERNEL) -> vm_area_dup(old)

    # free vma
    kmem_cache_free(vm_area_cachep, vma) -> vm_area_free(vma)

to the point where the old vma passed in to the vm_area_dup() function
isn't even used yet (because I've left all the old manual initialization
alone).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 6 insertions, 6 deletions

diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
index 3b38c717008a..e859246badca 100644
--- a/arch/ia64/kernel/perfmon.c
+++ b/arch/ia64/kernel/perfmon.c
@@ -2278,7 +2278,7 @@ pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t
 	DPRINT(("smpl_buf @%p\n", smpl_buf));
 
 	/* allocate vma */
-	vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
+	vma = vm_area_alloc();
 	if (!vma) {
 		DPRINT(("Cannot allocate vma\n"));
 		goto error_kmem;
@@ -2346,7 +2346,7 @@ pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t
 	return 0;
 
 error:
-	kmem_cache_free(vm_area_cachep, vma);
+	vm_area_free(vma);
 error_kmem:
 	pfm_rvfree(smpl_buf, size);
 
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 18278b448530..3f2321bffb72 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -114,7 +114,7 @@ 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 = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
+	vma = vm_area_alloc();
 	if (vma) {
 		INIT_LIST_HEAD(&vma->anon_vma_chain);
 		vma->vm_mm = current->mm;
@@ -125,7 +125,7 @@ ia64_init_addr_space (void)
 		down_write(&current->mm->mmap_sem);
 		if (insert_vm_struct(current->mm, vma)) {
 			up_write(&current->mm->mmap_sem);
-			kmem_cache_free(vm_area_cachep, vma);
+			vm_area_free(vma);
 			return;
 		}
 		up_write(&current->mm->mmap_sem);
@@ -133,7 +133,7 @@ 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 = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
+		vma = vm_area_alloc();
 		if (vma) {
 			INIT_LIST_HEAD(&vma->anon_vma_chain);
 			vma->vm_mm = current->mm;
@@ -144,7 +144,7 @@ ia64_init_addr_space (void)
 			down_write(&current->mm->mmap_sem);
 			if (insert_vm_struct(current->mm, vma)) {
 				up_write(&current->mm->mmap_sem);
-				kmem_cache_free(vm_area_cachep, vma);
+				vm_area_free(vma);
 				return;
 			}
 			up_write(&current->mm->mmap_sem);