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Commit a670468f authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
Browse files

mm: zero out the vma in vma_init() 



Rather than in vm_area_alloc().  To ensure that the various oddball
stack-based vmas are in a good state.  Some of the callers were zeroing
them out, others were not.

Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a3bf6ce3

arch/arm/kernel/process.c

+4 −5
Original line number Diff line number Diff line
@@ -330,16 +330,15 @@ unsigned long arch_randomize_brk(struct mm_struct *mm) 
 * atomic helpers. Insert it into the gate_vma so that it is visible

 * through ptrace and /proc/<pid>/mem.

 */

static struct vm_area_struct gate_vma = {

	.vm_start	= 0xffff0000,

	.vm_end		= 0xffff0000 + PAGE_SIZE,

	.vm_flags	= VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC,

};

static struct vm_area_struct gate_vma;



static int __init gate_vma_init(void)

{

	vma_init(&gate_vma, NULL);

	gate_vma.vm_page_prot = PAGE_READONLY_EXEC;

	gate_vma.vm_start = 0xffff0000;

	gate_vma.vm_end	= 0xffff0000 + PAGE_SIZE;

	gate_vma.vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC;

	return 0;

}

arch_initcall(gate_vma_init);

fs/hugetlbfs/inode.c

+0 −2
Original line number Diff line number Diff line
@@ -410,7 +410,6 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart, 
	int i, freed = 0;

	bool truncate_op = (lend == LLONG_MAX);



	memset(&pseudo_vma, 0, sizeof(struct vm_area_struct));

	vma_init(&pseudo_vma, current->mm);

	pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED);

	pagevec_init(&pvec);
@@ -595,7 +594,6 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset, 
	 * allocation routines.  If NUMA is configured, use page index

	 * as input to create an allocation policy.

	 */

	memset(&pseudo_vma, 0, sizeof(struct vm_area_struct));

	vma_init(&pseudo_vma, mm);

	pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED);

	pseudo_vma.vm_file = file;

include/linux/mm.h

+1 −0
Original line number Diff line number Diff line
@@ -456,6 +456,7 @@ static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm) 
{

	static const struct vm_operations_struct dummy_vm_ops = {};



	memset(vma, 0, sizeof(*vma));

	vma->vm_mm = mm;

	vma->vm_ops = &dummy_vm_ops;

	INIT_LIST_HEAD(&vma->anon_vma_chain);

kernel/fork.c

+2 −1
Original line number Diff line number Diff line
@@ -310,8 +310,9 @@ static struct kmem_cache *mm_cachep; 


struct vm_area_struct *vm_area_alloc(struct mm_struct *mm)

{

	struct vm_area_struct *vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);

	struct vm_area_struct *vma;



	vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);

	if (vma)

		vma_init(vma, mm);

	return vma;

mm/mempolicy.c

+0 −1
Original line number Diff line number Diff line
@@ -2504,7 +2504,6 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol) 
			goto put_new;



		/* Create pseudo-vma that contains just the policy */

		memset(&pvma, 0, sizeof(struct vm_area_struct));

		vma_init(&pvma, NULL);

		pvma.vm_end = TASK_SIZE;	/* policy covers entire file */

		mpol_set_shared_policy(sp, &pvma, new); /* adds ref */