mm: collapse security_vm_enough_memory() variants into a single function

Collapse security_vm_enough_memory() variants into a single function.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>

include/linux/security.h

@@ -1679,9 +1679,7 @@ int security_quotactl(int cmds, int type, int id, struct super_block *sb);
 int security_quota_on(struct dentry *dentry);
 int security_syslog(int type);
 int security_settime(const struct timespec *ts, const struct timezone *tz);
-int security_vm_enough_memory(long pages);
 int security_vm_enough_memory_mm(struct mm_struct *mm, long pages);
-int security_vm_enough_memory_kern(long pages);
 int security_bprm_set_creds(struct linux_binprm *bprm);
 int security_bprm_check(struct linux_binprm *bprm);
 void security_bprm_committing_creds(struct linux_binprm *bprm);
@@ -1902,25 +1900,11 @@ static inline int security_settime(const struct timespec *ts,
 	return cap_settime(ts, tz);
 }
 
-static inline int security_vm_enough_memory(long pages)
-{
-	WARN_ON(current->mm == NULL);
-	return cap_vm_enough_memory(current->mm, pages);
-}
-
 static inline int security_vm_enough_memory_mm(struct mm_struct *mm, long pages)
 {
-	WARN_ON(mm == NULL);
 	return cap_vm_enough_memory(mm, pages);
 }
 
-static inline int security_vm_enough_memory_kern(long pages)
-{
-	/* If current->mm is a kernel thread then we will pass NULL,
-	   for this specific case that is fine */
-	return cap_vm_enough_memory(current->mm, pages);
-}
-
 static inline int security_bprm_set_creds(struct linux_binprm *bprm)
 {
 	return cap_bprm_set_creds(bprm);

kernel/fork.c

@@ -355,7 +355,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
 		charge = 0;
 		if (mpnt->vm_flags & VM_ACCOUNT) {
 			unsigned int len = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
-			if (security_vm_enough_memory(len))
+			if (security_vm_enough_memory_mm(oldmm, len)) /* sic */
 				goto fail_nomem;
 			charge = len;
 		}

mm/mmap.c

@@ -1235,7 +1235,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
 	 */
 	if (accountable_mapping(file, vm_flags)) {
 		charged = len >> PAGE_SHIFT;
-		if (security_vm_enough_memory(charged))
+		if (security_vm_enough_memory_mm(mm, charged))
 			return -ENOMEM;
 		vm_flags |= VM_ACCOUNT;
 	}
@@ -2169,7 +2169,7 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
 	if (mm->map_count > sysctl_max_map_count)
 		return -ENOMEM;
 
-	if (security_vm_enough_memory(len >> PAGE_SHIFT))
+	if (security_vm_enough_memory_mm(mm, len >> PAGE_SHIFT))
 		return -ENOMEM;
 
 	/* Can we just expand an old private anonymous mapping? */

mm/mprotect.c

@@ -168,7 +168,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
 		if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB|
 						VM_SHARED|VM_NORESERVE))) {
 			charged = nrpages;
-			if (security_vm_enough_memory(charged))
+			if (security_vm_enough_memory_mm(mm, charged))
 				return -ENOMEM;
 			newflags |= VM_ACCOUNT;
 		}

mm/mremap.c

@@ -329,7 +329,7 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr,
 
 	if (vma->vm_flags & VM_ACCOUNT) {
 		unsigned long charged = (new_len - old_len) >> PAGE_SHIFT;
-		if (security_vm_enough_memory(charged))
+		if (security_vm_enough_memory_mm(mm, charged))
 			goto Efault;
 		*p = charged;
 	}

mm/shmem.c

@@ -127,7 +127,7 @@ static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb)
 static inline int shmem_acct_size(unsigned long flags, loff_t size)
 {
 	return (flags & VM_NORESERVE) ?
-		0 : security_vm_enough_memory_kern(VM_ACCT(size));
+		0 : security_vm_enough_memory_mm(current->mm, VM_ACCT(size));
 }
 
 static inline void shmem_unacct_size(unsigned long flags, loff_t size)
@@ -145,7 +145,7 @@ static inline void shmem_unacct_size(unsigned long flags, loff_t size)
 static inline int shmem_acct_block(unsigned long flags)
 {
 	return (flags & VM_NORESERVE) ?
-		security_vm_enough_memory_kern(VM_ACCT(PAGE_CACHE_SIZE)) : 0;
+		security_vm_enough_memory_mm(current->mm, VM_ACCT(PAGE_CACHE_SIZE)) : 0;
 }
 
 static inline void shmem_unacct_blocks(unsigned long flags, long pages)

mm/swapfile.c

@@ -1563,6 +1563,8 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	BUG_ON(!current->mm);
+
 	pathname = getname(specialfile);
 	err = PTR_ERR(pathname);
 	if (IS_ERR(pathname))
@@ -1590,7 +1592,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 		spin_unlock(&swap_lock);
 		goto out_dput;
 	}
-	if (!security_vm_enough_memory(p->pages))
+	if (!security_vm_enough_memory_mm(current->mm, p->pages))
 		vm_unacct_memory(p->pages);
 	else {
 		err = -ENOMEM;

security/security.c

@@ -187,25 +187,11 @@ int security_settime(const struct timespec *ts, const struct timezone *tz)
 	return security_ops->settime(ts, tz);
 }
 
-int security_vm_enough_memory(long pages)
-{
-	WARN_ON(current->mm == NULL);
-	return security_ops->vm_enough_memory(current->mm, pages);
-}
-
 int security_vm_enough_memory_mm(struct mm_struct *mm, long pages)
 {
-	WARN_ON(mm == NULL);
 	return security_ops->vm_enough_memory(mm, pages);
 }
 
-int security_vm_enough_memory_kern(long pages)
-{
-	/* If current->mm is a kernel thread then we will pass NULL,
-	   for this specific case that is fine */
-	return security_ops->vm_enough_memory(current->mm, pages);
-}
-
 int security_bprm_set_creds(struct linux_binprm *bprm)
 {
 	return security_ops->bprm_set_creds(bprm);