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authorAndrew Morton <akpm@linux-foundation.org>2018-08-21 21:53:06 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-22 10:52:44 -0700
commita670468f5e0b5fad4db6e4d195f15915dc2a35c1 (patch)
tree57540edd0f9f24335154139c17695a13b594fe58
parenta3bf6ce366496016990d8578af74673ea04178ff (diff)
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: Kirill 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/arm/kernel/process.c9
-rw-r--r--fs/hugetlbfs/inode.c2
-rw-r--r--include/linux/mm.h1
-rw-r--r--kernel/fork.c3
-rw-r--r--mm/mempolicy.c1
-rw-r--r--mm/shmem.c1
6 files changed, 7 insertions, 10 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index d9c299133111..82ab015bf42b 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -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);
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 346a146c7617..32920a10100e 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -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;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a3cae495f9ce..3a4b87d1a59a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -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);
diff --git a/kernel/fork.c b/kernel/fork.c
index 5ee74c113381..8c760effa42e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -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;
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 01f1a14facc4..4861ba738d6f 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -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 */
diff --git a/mm/shmem.c b/mm/shmem.c
index c48c79018a7c..fb04baacc9fa 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1421,7 +1421,6 @@ static void shmem_pseudo_vma_init(struct vm_area_struct *vma,
struct shmem_inode_info *info, pgoff_t index)
{
/* Create a pseudo vma that just contains the policy */
- memset(vma, 0, sizeof(*vma));
vma_init(vma, NULL);
/* Bias interleave by inode number to distribute better across nodes */
vma->vm_pgoff = index + info->vfs_inode.i_ino;