Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull security subsystem updates for 3.4 from James Morris:
"The main addition here is the new Yama security module from Kees Cook,
which was discussed at the Linux Security Summit last year. Its
purpose is to collect miscellaneous DAC security enhancements in one
place. This also marks a departure in policy for LSM modules, which
were previously limited to being standalone access control systems.
Chromium OS is using Yama, and I believe there are plans for Ubuntu,
at least.

This patchset also includes maintenance updates for AppArmor, TOMOYO
and others."

Fix trivial conflict in <net/sock.h> due to the jumo_label->static_key
rename.

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (38 commits)
AppArmor: Fix location of const qualifier on generated string tables
TOMOYO: Return error if fails to delete a domain
AppArmor: add const qualifiers to string arrays
AppArmor: Add ability to load extended policy
TOMOYO: Return appropriate value to poll().
AppArmor: Move path failure information into aa_get_name and rename
AppArmor: Update dfa matching routines.
AppArmor: Minor cleanup of d_namespace_path to consolidate error handling
AppArmor: Retrieve the dentry_path for error reporting when path lookup fails
AppArmor: Add const qualifiers to generated string tables
AppArmor: Fix oops in policy unpack auditing
AppArmor: Fix error returned when a path lookup is disconnected
KEYS: testing wrong bit for KEY_FLAG_REVOKED
TOMOYO: Fix mount flags checking order.
security: fix ima kconfig warning
AppArmor: Fix the error case for chroot relative path name lookup
AppArmor: fix mapping of META_READ to audit and quiet flags
AppArmor: Fix underflow in xindex calculation
AppArmor: Fix dropping of allowed operations that are force audited
AppArmor: Add mising end of structure test to caps unpacking
...

Documentation/networking/dns_resolver.txt

···
      If _expiry is non-NULL, the expiry time (TTL) of the result will be
      returned also.
 
+The kernel maintains an internal keyring in which it caches looked up keys.
+This can be cleared by any process that has the CAP_SYS_ADMIN capability by
+the use of KEYCTL_KEYRING_CLEAR on the keyring ID.
+
 
 ===============================
 READING DNS KEYS FROM USERSPACE

Documentation/security/00-INDEX

···
 	- how to get started with the SELinux security enhancement.
 Smack.txt
 	- documentation on the Smack Linux Security Module.
+Yama.txt
+	- documentation on the Yama Linux Security Module.
 apparmor.txt
 	- documentation on the AppArmor security extension.
 credentials.txt

Documentation/security/Yama.txt

···
+Yama is a Linux Security Module that collects a number of system-wide DAC
+security protections that are not handled by the core kernel itself. To
+select it at boot time, specify "security=yama" (though this will disable
+any other LSM).
+
+Yama is controlled through sysctl in /proc/sys/kernel/yama:
+
+- ptrace_scope
+
+==============================================================
+
+ptrace_scope:
+
+As Linux grows in popularity, it will become a larger target for
+malware. One particularly troubling weakness of the Linux process
+interfaces is that a single user is able to examine the memory and
+running state of any of their processes. For example, if one application
+(e.g. Pidgin) was compromised, it would be possible for an attacker to
+attach to other running processes (e.g. Firefox, SSH sessions, GPG agent,
+etc) to extract additional credentials and continue to expand the scope
+of their attack without resorting to user-assisted phishing.
+
+This is not a theoretical problem. SSH session hijacking
+(http://www.storm.net.nz/projects/7) and arbitrary code injection
+(http://c-skills.blogspot.com/2007/05/injectso.html) attacks already
+exist and remain possible if ptrace is allowed to operate as before.
+Since ptrace is not commonly used by non-developers and non-admins, system
+builders should be allowed the option to disable this debugging system.
+
+For a solution, some applications use prctl(PR_SET_DUMPABLE, ...) to
+specifically disallow such ptrace attachment (e.g. ssh-agent), but many
+do not. A more general solution is to only allow ptrace directly from a
+parent to a child process (i.e. direct "gdb EXE" and "strace EXE" still
+work), or with CAP_SYS_PTRACE (i.e. "gdb --pid=PID", and "strace -p PID"
+still work as root).
+
+For software that has defined application-specific relationships
+between a debugging process and its inferior (crash handlers, etc),
+prctl(PR_SET_PTRACER, pid, ...) can be used. An inferior can declare which
+other process (and its descendents) are allowed to call PTRACE_ATTACH
+against it. Only one such declared debugging process can exists for
+each inferior at a time. For example, this is used by KDE, Chromium, and
+Firefox's crash handlers, and by Wine for allowing only Wine processes
+to ptrace each other. If a process wishes to entirely disable these ptrace
+restrictions, it can call prctl(PR_SET_PTRACER, PR_SET_PTRACER_ANY, ...)
+so that any otherwise allowed process (even those in external pid namespaces)
+may attach.
+
+The sysctl settings are:
+
+0 - classic ptrace permissions: a process can PTRACE_ATTACH to any other
+    process running under the same uid, as long as it is dumpable (i.e.
+    did not transition uids, start privileged, or have called
+    prctl(PR_SET_DUMPABLE...) already).
+
+1 - restricted ptrace: a process must have a predefined relationship
+    with the inferior it wants to call PTRACE_ATTACH on. By default,
+    this relationship is that of only its descendants when the above
+    classic criteria is also met. To change the relationship, an
+    inferior can call prctl(PR_SET_PTRACER, debugger, ...) to declare
+    an allowed debugger PID to call PTRACE_ATTACH on the inferior.
+
+The original children-only logic was based on the restrictions in grsecurity.
+
+==============================================================

Documentation/security/keys.txt

···
      process must have write permission on the keyring, and it must be a
      keyring (or else error ENOTDIR will result).
 
+     This function can also be used to clear special kernel keyrings if they
+     are appropriately marked if the user has CAP_SYS_ADMIN capability.  The
+     DNS resolver cache keyring is an example of this.
+
 
  (*) Link a key into a keyring:
 

drivers/char/tpm/Kconfig

···
 menuconfig TCG_TPM
 	tristate "TPM Hardware Support"
 	depends on HAS_IOMEM
-	depends on EXPERIMENTAL
 	select SECURITYFS
 	---help---
 	  If you have a TPM security chip in your system, which

drivers/char/tpm/tpm.c

···
 	ret_size = atomic_read(&chip->data_pending);
 	atomic_set(&chip->data_pending, 0);
 	if (ret_size > 0) {	/* relay data */
+		ssize_t orig_ret_size = ret_size;
 		if (size < ret_size)
 			ret_size = size;
 
 		mutex_lock(&chip->buffer_mutex);
 		rc = copy_to_user(buf, chip->data_buffer, ret_size);
-		memset(chip->data_buffer, 0, ret_size);
+		memset(chip->data_buffer, 0, orig_ret_size);
 		if (rc)
 			ret_size = -EFAULT;
 

drivers/char/tpm/tpm.h

···
 	wait_queue_head_t int_queue;
 };
 
+#define TPM_VID_INTEL    0x8086
+
 struct tpm_chip {
 	struct device *dev;	/* Device stuff */
 

drivers/char/tpm/tpm_tis.c

···
 		0x00, 0x00, 0x00, 0xf1
 	};
 	size_t len = sizeof(cmd_getticks);
-	int rem_itpm = itpm;
+	bool rem_itpm = itpm;
+	u16 vendor = ioread16(chip->vendor.iobase + TPM_DID_VID(0));
+
+	/* probe only iTPMS */
+	if (vendor != TPM_VID_INTEL)
+		return 0;
 
 	itpm = 0;
 
···
 out:
 	itpm = rem_itpm;
 	tpm_tis_ready(chip);
-	/* some TPMs need a break here otherwise they will not work
-	 * correctly on the immediately subsequent command */
-	msleep(chip->vendor.timeout_b);
 	release_locality(chip, chip->vendor.locality, 0);
 
 	return rc;
···
 			resource_size_t len, unsigned int irq)
 {
 	u32 vendor, intfcaps, intmask;
-	int rc, i, irq_s, irq_e;
+	int rc, i, irq_s, irq_e, probe;
 	struct tpm_chip *chip;
 
 	if (!(chip = tpm_register_hardware(dev, &tpm_tis)))
···
 		 vendor >> 16, ioread8(chip->vendor.iobase + TPM_RID(0)));
 
 	if (!itpm) {
-		itpm = probe_itpm(chip);
-		if (itpm < 0) {
+		probe = probe_itpm(chip);
+		if (probe < 0) {
 			rc = -ENODEV;
 			goto out_err;
 		}
+		itpm = (probe == 0) ? 0 : 1;
 	}
 
 	if (itpm)

drivers/net/macvtap.c

···
 #include <linux/init.h>
 #include <linux/wait.h>
 #include <linux/cdev.h>
+#include <linux/idr.h>
 #include <linux/fs.h>
 
 #include <net/net_namespace.h>

drivers/target/iscsi/iscsi_target.c

···
 #include <linux/crypto.h>
 #include <linux/completion.h>
 #include <linux/module.h>
+#include <linux/idr.h>
 #include <asm/unaligned.h>
 #include <scsi/scsi_device.h>
 #include <scsi/iscsi_proto.h>

drivers/target/iscsi/iscsi_target_login.c

···
 #include <linux/string.h>
 #include <linux/kthread.h>
 #include <linux/crypto.h>
+#include <linux/idr.h>
 #include <scsi/iscsi_proto.h>
 #include <target/target_core_base.h>
 #include <target/target_core_fabric.h>

fs/cifs/cifsacl.c

···
 
 	/* instruct request_key() to use this special keyring as a cache for
 	 * the results it looks up */
+	set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 	cred->thread_keyring = keyring;
 	cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 	root_cred = cred;

fs/nfs/client.c

···
 #include <linux/inet.h>
 #include <linux/in6.h>
 #include <linux/slab.h>
+#include <linux/idr.h>
 #include <net/ipv6.h>
 #include <linux/nfs_xdr.h>
 #include <linux/sunrpc/bc_xprt.h>

fs/nfs/idmap.c

···
 	if (ret < 0)
 		goto failed_put_key;
 
+	set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 	cred->thread_keyring = keyring;
 	cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 	id_resolver_cache = cred;

fs/proc/proc_sysctl.c

···
 #include <linux/poll.h>
 #include <linux/proc_fs.h>
 #include <linux/security.h>
+#include <linux/sched.h>
 #include <linux/namei.h>
+#include <linux/mm.h>
 #include "internal.h"
 
 static const struct dentry_operations proc_sys_dentry_operations;

fs/quota/dquot.c

···
 #include <linux/module.h>
 #include <linux/proc_fs.h>
 #include <linux/security.h>
+#include <linux/sched.h>
 #include <linux/kmod.h>
 #include <linux/namei.h>
 #include <linux/capability.h>

fs/super.c

···
 #include <linux/backing-dev.h>
 #include <linux/rculist_bl.h>
 #include <linux/cleancache.h>
+#include <linux/fsnotify.h>
 #include "internal.h"
 
 

include/linux/key.h

···
 #define KEY_FLAG_IN_QUOTA	3	/* set if key consumes quota */
 #define KEY_FLAG_USER_CONSTRUCT	4	/* set if key is being constructed in userspace */
 #define KEY_FLAG_NEGATIVE	5	/* set if key is negative */
+#define KEY_FLAG_ROOT_CAN_CLEAR	6	/* set if key can be cleared by root without permission */
 
 	/* the description string
 	 * - this is used to match a key against search criteria

include/linux/prctl.h

···
 # define PR_SET_MM_START_BRK		6
 # define PR_SET_MM_BRK			7
 
+/*
+ * Set specific pid that is allowed to ptrace the current task.
+ * A value of 0 mean "no process".
+ */
+#define PR_SET_PTRACER 0x59616d61
+# define PR_SET_PTRACER_ANY ((unsigned long)-1)
+
 #endif /* _LINUX_PRCTL_H */

include/linux/security.h

···
 #ifndef __LINUX_SECURITY_H
 #define __LINUX_SECURITY_H
 
-#include <linux/fs.h>
-#include <linux/fsnotify.h>
-#include <linux/binfmts.h>
-#include <linux/dcache.h>
-#include <linux/signal.h>
-#include <linux/resource.h>
-#include <linux/sem.h>
-#include <linux/shm.h>
-#include <linux/mm.h> /* PAGE_ALIGN */
-#include <linux/msg.h>
-#include <linux/sched.h>
 #include <linux/key.h>
-#include <linux/xfrm.h>
+#include <linux/capability.h>
 #include <linux/slab.h>
-#include <linux/xattr.h>
-#include <net/flow.h>
+#include <linux/err.h>
+
+struct linux_binprm;
+struct cred;
+struct rlimit;
+struct siginfo;
+struct sem_array;
+struct sembuf;
+struct kern_ipc_perm;
+struct audit_context;
+struct super_block;
+struct inode;
+struct dentry;
+struct file;
+struct vfsmount;
+struct path;
+struct qstr;
+struct nameidata;
+struct iattr;
+struct fown_struct;
+struct file_operations;
+struct shmid_kernel;
+struct msg_msg;
+struct msg_queue;
+struct xattr;
+struct xfrm_sec_ctx;
+struct mm_struct;
 
 /* Maximum number of letters for an LSM name string */
 #define SECURITY_NAME_MAX	10
···
 struct ctl_table;
 struct audit_krule;
 struct user_namespace;
+struct timezone;
 
 /*
  * These functions are in security/capability.c and are used
···
 #define LSM_UNSAFE_PTRACE_CAP	4
 
 #ifdef CONFIG_MMU
-/*
- * If a hint addr is less than mmap_min_addr change hint to be as
- * low as possible but still greater than mmap_min_addr
- */
-static inline unsigned long round_hint_to_min(unsigned long hint)
-{
-	hint &= PAGE_MASK;
-	if (((void *)hint != NULL) &&
-	    (hint < mmap_min_addr))
-		return PAGE_ALIGN(mmap_min_addr);
-	return hint;
-}
 extern int mmap_min_addr_handler(struct ctl_table *table, int write,
 				 void __user *buffer, size_t *lenp, loff_t *ppos);
 #endif
···
  *	manual page for definitions of the @clone_flags.
  *	@clone_flags contains the flags indicating what should be shared.
  *	Return 0 if permission is granted.
+ * @task_free:
+ *	@task task being freed
+ *	Handle release of task-related resources. (Note that this can be called
+ *	from interrupt context.)
  * @cred_alloc_blank:
  *	@cred points to the credentials.
  *	@gfp indicates the atomicity of any memory allocations.
···
 	int (*dentry_open) (struct file *file, const struct cred *cred);
 
 	int (*task_create) (unsigned long clone_flags);
+	void (*task_free) (struct task_struct *task);
 	int (*cred_alloc_blank) (struct cred *cred, gfp_t gfp);
 	void (*cred_free) (struct cred *cred);
 	int (*cred_prepare)(struct cred *new, const struct cred *old,
···
 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);
···
 int security_file_receive(struct file *file);
 int security_dentry_open(struct file *file, const struct cred *cred);
 int security_task_create(unsigned long clone_flags);
+void security_task_free(struct task_struct *task);
 int security_cred_alloc_blank(struct cred *cred, gfp_t gfp);
 void security_cred_free(struct cred *cred);
 int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
···
 	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 0;
 }
+
+static inline void security_task_free(struct task_struct *task)
+{ }
 
 static inline int security_cred_alloc_blank(struct cred *cred, gfp_t gfp)
 {

include/net/sock.h

···
 #include <linux/memcontrol.h>
 #include <linux/res_counter.h>
 #include <linux/static_key.h>
+#include <linux/aio.h>
+#include <linux/sched.h>
 
 #include <linux/filter.h>
 #include <linux/rculist_nulls.h>

ipc/msgutil.c

···
 #include <linux/security.h>
 #include <linux/slab.h>
 #include <linux/ipc.h>
+#include <linux/msg.h>
 #include <linux/ipc_namespace.h>
+#include <linux/utsname.h>
 #include <asm/uaccess.h>
 
 #include "util.h"

kernel/cred.c

···
 #include <linux/keyctl.h>
 #include <linux/init_task.h>
 #include <linux/security.h>
+#include <linux/binfmts.h>
 #include <linux/cn_proc.h>
 
 #if 0

kernel/exit.c

···
 #include <linux/hw_breakpoint.h>
 #include <linux/oom.h>
 #include <linux/writeback.h>
+#include <linux/shm.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>

kernel/fork.c

···
 	WARN_ON(atomic_read(&tsk->usage));
 	WARN_ON(tsk == current);
 
+	security_task_free(tsk);
 	exit_creds(tsk);
 	delayacct_tsk_free(tsk);
 	put_signal_struct(tsk->signal);
···
 		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;
 		}

kernel/sched/core.c

···
 #include <linux/ftrace.h>
 #include <linux/slab.h>
 #include <linux/init_task.h>
+#include <linux/binfmts.h>
 
 #include <asm/tlb.h>
 #include <asm/irq_regs.h>

kernel/sysctl.c

···
 #include <linux/oom.h>
 #include <linux/kmod.h>
 #include <linux/capability.h>
+#include <linux/binfmts.h>
 
 #include <asm/uaccess.h>
 #include <asm/processor.h>

mm/mmap.c

···
 #endif /* CONFIG_PROC_FS */
 
 /*
+ * If a hint addr is less than mmap_min_addr change hint to be as
+ * low as possible but still greater than mmap_min_addr
+ */
+static inline unsigned long round_hint_to_min(unsigned long hint)
+{
+	hint &= PAGE_MASK;
+	if (((void *)hint != NULL) &&
+	    (hint < mmap_min_addr))
+		return PAGE_ALIGN(mmap_min_addr);
+	return hint;
+}
+
+/*
  * The caller must hold down_write(&current->mm->mmap_sem).
  */
 
···
 	 */
 	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;
 	}
···
 	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

···
 		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

···
 
 	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

···
 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)
···
 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

···
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	BUG_ON(!current->mm);
+
 	pathname = getname(specialfile);
 	err = PTR_ERR(pathname);
 	if (IS_ERR(pathname))
···
 		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;

net/dns_resolver/dns_key.c

···
 
 	/* instruct request_key() to use this special keyring as a cache for
 	 * the results it looks up */
+	set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
 	cred->thread_keyring = keyring;
 	cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
 	dns_resolver_cache = cred;

security/Kconfig

···
 source security/smack/Kconfig
 source security/tomoyo/Kconfig
 source security/apparmor/Kconfig
+source security/yama/Kconfig
 
 source security/integrity/Kconfig
 
···
 	default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
 	default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
 	default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
+	default DEFAULT_SECURITY_YAMA if SECURITY_YAMA
 	default DEFAULT_SECURITY_DAC
 
 	help
···
 	config DEFAULT_SECURITY_APPARMOR
 		bool "AppArmor" if SECURITY_APPARMOR=y
 
+	config DEFAULT_SECURITY_YAMA
+		bool "Yama" if SECURITY_YAMA=y
+
 	config DEFAULT_SECURITY_DAC
 		bool "Unix Discretionary Access Controls"
 
···
 	default "smack" if DEFAULT_SECURITY_SMACK
 	default "tomoyo" if DEFAULT_SECURITY_TOMOYO
 	default "apparmor" if DEFAULT_SECURITY_APPARMOR
+	default "yama" if DEFAULT_SECURITY_YAMA
 	default "" if DEFAULT_SECURITY_DAC
 
 endmenu

security/Makefile

···
 subdir-$(CONFIG_SECURITY_SMACK)		+= smack
 subdir-$(CONFIG_SECURITY_TOMOYO)        += tomoyo
 subdir-$(CONFIG_SECURITY_APPARMOR)	+= apparmor
+subdir-$(CONFIG_SECURITY_YAMA)		+= yama
 
 # always enable default capabilities
 obj-y					+= commoncap.o
···
 obj-$(CONFIG_AUDIT)			+= lsm_audit.o
 obj-$(CONFIG_SECURITY_TOMOYO)		+= tomoyo/built-in.o
 obj-$(CONFIG_SECURITY_APPARMOR)		+= apparmor/built-in.o
+obj-$(CONFIG_SECURITY_YAMA)		+= yama/built-in.o
 obj-$(CONFIG_CGROUP_DEVICE)		+= device_cgroup.o
 
 # Object integrity file lists

security/apparmor/Makefile

···
 # to
 #    [1] = "dac_override",
 quiet_cmd_make-caps = GEN     $@
-cmd_make-caps = echo "static const char *capability_names[] = {" > $@ ;\
+cmd_make-caps = echo "static const char *const capability_names[] = {" > $@ ;\
 	sed $< >>$@ -r -n -e '/CAP_FS_MASK/d' \
 	-e 's/^\#define[ \t]+CAP_([A-Z0-9_]+)[ \t]+([0-9]+)/[\2] = "\L\1",/p';\
 	echo "};" >> $@
···
 #    [RLIMIT_STACK] = "stack",
 #
 # and build a second integer table (with the second sed cmd), that maps
-# RLIMIT defines to the order defined in asm-generic/resource.h  Thi is
+# RLIMIT defines to the order defined in asm-generic/resource.h  This is
 # required by policy load to map policy ordering of RLIMITs to internal
 # ordering for architectures that redefine an RLIMIT.
 # Transforms lines from
 #    #define RLIMIT_STACK		3	/* max stack size */
 # to
 # RLIMIT_STACK, 
+#
+# and build the securityfs entries for the mapping.
+# Transforms lines from
+#    #define RLIMIT_FSIZE        1   /* Maximum filesize */
+#    #define RLIMIT_STACK		3	/* max stack size */
+# to
+# #define AA_FS_RLIMIT_MASK "fsize stack"
 quiet_cmd_make-rlim = GEN     $@
-cmd_make-rlim = echo "static const char *rlim_names[] = {" > $@ ;\
+cmd_make-rlim = echo "static const char *const rlim_names[RLIM_NLIMITS] = {" \
+	> $@ ;\
 	sed $< >> $@ -r -n \
 	    -e 's/^\# ?define[ \t]+(RLIMIT_([A-Z0-9_]+)).*/[\1] = "\L\2",/p';\
 	echo "};" >> $@ ;\
-	echo "static const int rlim_map[] = {" >> $@ ;\
+	echo "static const int rlim_map[RLIM_NLIMITS] = {" >> $@ ;\
 	sed -r -n "s/^\# ?define[ \t]+(RLIMIT_[A-Z0-9_]+).*/\1,/p" $< >> $@ ;\
-	echo "};" >> $@
+	echo "};" >> $@ ; \
+	echo -n '\#define AA_FS_RLIMIT_MASK "' >> $@ ;\
+	sed -r -n 's/^\# ?define[ \t]+RLIMIT_([A-Z0-9_]+).*/\L\1/p' $< | \
+	    tr '\n' ' ' | sed -e 's/ $$/"\n/' >> $@
 
 $(obj)/capability.o : $(obj)/capability_names.h
 $(obj)/resource.o : $(obj)/rlim_names.h
-$(obj)/capability_names.h : $(srctree)/include/linux/capability.h
+$(obj)/capability_names.h : $(srctree)/include/linux/capability.h \
+			    $(src)/Makefile
 	$(call cmd,make-caps)
-$(obj)/rlim_names.h : $(srctree)/include/asm-generic/resource.h
+$(obj)/rlim_names.h : $(srctree)/include/asm-generic/resource.h \
+		      $(src)/Makefile
 	$(call cmd,make-rlim)

security/apparmor/apparmorfs.c

···
 #include <linux/seq_file.h>
 #include <linux/uaccess.h>
 #include <linux/namei.h>
+#include <linux/capability.h>
 
 #include "include/apparmor.h"
 #include "include/apparmorfs.h"
 #include "include/audit.h"
 #include "include/context.h"
 #include "include/policy.h"
+#include "include/resource.h"
 
 /**
  * aa_simple_write_to_buffer - common routine for getting policy from user
···
 	.llseek = default_llseek,
 };
 
+static int aa_fs_seq_show(struct seq_file *seq, void *v)
+{
+	struct aa_fs_entry *fs_file = seq->private;
+
+	if (!fs_file)
+		return 0;
+
+	switch (fs_file->v_type) {
+	case AA_FS_TYPE_BOOLEAN:
+		seq_printf(seq, "%s\n", fs_file->v.boolean ? "yes" : "no");
+		break;
+	case AA_FS_TYPE_STRING:
+		seq_printf(seq, "%s\n", fs_file->v.string);
+		break;
+	case AA_FS_TYPE_U64:
+		seq_printf(seq, "%#08lx\n", fs_file->v.u64);
+		break;
+	default:
+		/* Ignore unpritable entry types. */
+		break;
+	}
+
+	return 0;
+}
+
+static int aa_fs_seq_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, aa_fs_seq_show, inode->i_private);
+}
+
+const struct file_operations aa_fs_seq_file_ops = {
+	.owner		= THIS_MODULE,
+	.open		= aa_fs_seq_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
 /** Base file system setup **/
 
-static struct dentry *aa_fs_dentry __initdata;
+static struct aa_fs_entry aa_fs_entry_file[] = {
+	AA_FS_FILE_STRING("mask", "create read write exec append mmap_exec " \
+				  "link lock"),
+	{ }
+};
 
-static void __init aafs_remove(const char *name)
+static struct aa_fs_entry aa_fs_entry_domain[] = {
+	AA_FS_FILE_BOOLEAN("change_hat",	1),
+	AA_FS_FILE_BOOLEAN("change_hatv",	1),
+	AA_FS_FILE_BOOLEAN("change_onexec",	1),
+	AA_FS_FILE_BOOLEAN("change_profile",	1),
+	{ }
+};
+
+static struct aa_fs_entry aa_fs_entry_features[] = {
+	AA_FS_DIR("domain",			aa_fs_entry_domain),
+	AA_FS_DIR("file",			aa_fs_entry_file),
+	AA_FS_FILE_U64("capability",		VFS_CAP_FLAGS_MASK),
+	AA_FS_DIR("rlimit",			aa_fs_entry_rlimit),
+	{ }
+};
+
+static struct aa_fs_entry aa_fs_entry_apparmor[] = {
+	AA_FS_FILE_FOPS(".load", 0640, &aa_fs_profile_load),
+	AA_FS_FILE_FOPS(".replace", 0640, &aa_fs_profile_replace),
+	AA_FS_FILE_FOPS(".remove", 0640, &aa_fs_profile_remove),
+	AA_FS_DIR("features", aa_fs_entry_features),
+	{ }
+};
+
+static struct aa_fs_entry aa_fs_entry =
+	AA_FS_DIR("apparmor", aa_fs_entry_apparmor);
+
+/**
+ * aafs_create_file - create a file entry in the apparmor securityfs
+ * @fs_file: aa_fs_entry to build an entry for (NOT NULL)
+ * @parent: the parent dentry in the securityfs
+ *
+ * Use aafs_remove_file to remove entries created with this fn.
+ */
+static int __init aafs_create_file(struct aa_fs_entry *fs_file,
+				   struct dentry *parent)
 {
-	struct dentry *dentry;
+	int error = 0;
 
-	dentry = lookup_one_len(name, aa_fs_dentry, strlen(name));
-	if (!IS_ERR(dentry)) {
-		securityfs_remove(dentry);
-		dput(dentry);
+	fs_file->dentry = securityfs_create_file(fs_file->name,
+						 S_IFREG | fs_file->mode,
+						 parent, fs_file,
+						 fs_file->file_ops);
+	if (IS_ERR(fs_file->dentry)) {
+		error = PTR_ERR(fs_file->dentry);
+		fs_file->dentry = NULL;
 	}
+	return error;
 }
 
 /**
- * aafs_create - create an entry in the apparmor filesystem
- * @name: name of the entry (NOT NULL)
- * @mask: file permission mask of the file
- * @fops: file operations for the file (NOT NULL)
+ * aafs_create_dir - recursively create a directory entry in the securityfs
+ * @fs_dir: aa_fs_entry (and all child entries) to build (NOT NULL)
+ * @parent: the parent dentry in the securityfs
  *
- * Used aafs_remove to remove entries created with this fn.
+ * Use aafs_remove_dir to remove entries created with this fn.
  */
-static int __init aafs_create(const char *name, umode_t mask,
-			      const struct file_operations *fops)
+static int __init aafs_create_dir(struct aa_fs_entry *fs_dir,
+				  struct dentry *parent)
 {
-	struct dentry *dentry;
+	int error;
+	struct aa_fs_entry *fs_file;
 
-	dentry = securityfs_create_file(name, S_IFREG | mask, aa_fs_dentry,
-					NULL, fops);
+	fs_dir->dentry = securityfs_create_dir(fs_dir->name, parent);
+	if (IS_ERR(fs_dir->dentry)) {
+		error = PTR_ERR(fs_dir->dentry);
+		fs_dir->dentry = NULL;
+		goto failed;
+	}
 
-	return IS_ERR(dentry) ? PTR_ERR(dentry) : 0;
+	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
+		if (fs_file->v_type == AA_FS_TYPE_DIR)
+			error = aafs_create_dir(fs_file, fs_dir->dentry);
+		else
+			error = aafs_create_file(fs_file, fs_dir->dentry);
+		if (error)
+			goto failed;
+	}
+
+	return 0;
+
+failed:
+	return error;
+}
+
+/**
+ * aafs_remove_file - drop a single file entry in the apparmor securityfs
+ * @fs_file: aa_fs_entry to detach from the securityfs (NOT NULL)
+ */
+static void __init aafs_remove_file(struct aa_fs_entry *fs_file)
+{
+	if (!fs_file->dentry)
+		return;
+
+	securityfs_remove(fs_file->dentry);
+	fs_file->dentry = NULL;
+}
+
+/**
+ * aafs_remove_dir - recursively drop a directory entry from the securityfs
+ * @fs_dir: aa_fs_entry (and all child entries) to detach (NOT NULL)
+ */
+static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir)
+{
+	struct aa_fs_entry *fs_file;
+
+	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
+		if (fs_file->v_type == AA_FS_TYPE_DIR)
+			aafs_remove_dir(fs_file);
+		else
+			aafs_remove_file(fs_file);
+	}
+
+	aafs_remove_file(fs_dir);
 }
 
 /**
···
  */
 void __init aa_destroy_aafs(void)
 {
-	if (aa_fs_dentry) {
-		aafs_remove(".remove");
-		aafs_remove(".replace");
-		aafs_remove(".load");
-
-		securityfs_remove(aa_fs_dentry);
-		aa_fs_dentry = NULL;
-	}
+	aafs_remove_dir(&aa_fs_entry);
 }
 
 /**
···
 	if (!apparmor_initialized)
 		return 0;
 
-	if (aa_fs_dentry) {
+	if (aa_fs_entry.dentry) {
 		AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
 		return -EEXIST;
 	}
 
-	aa_fs_dentry = securityfs_create_dir("apparmor", NULL);
-	if (IS_ERR(aa_fs_dentry)) {
-		error = PTR_ERR(aa_fs_dentry);
-		aa_fs_dentry = NULL;
-		goto error;
-	}
-
-	error = aafs_create(".load", 0640, &aa_fs_profile_load);
-	if (error)
-		goto error;
-	error = aafs_create(".replace", 0640, &aa_fs_profile_replace);
-	if (error)
-		goto error;
-	error = aafs_create(".remove", 0640, &aa_fs_profile_remove);
+	/* Populate fs tree. */
+	error = aafs_create_dir(&aa_fs_entry, NULL);
 	if (error)
 		goto error;
 

security/apparmor/audit.c

···
 #include "include/audit.h"
 #include "include/policy.h"
 
-const char *op_table[] = {
+const char *const op_table[] = {
 	"null",
 
 	"sysctl",
···
 	"profile_remove"
 };
 
-const char *audit_mode_names[] = {
+const char *const audit_mode_names[] = {
 	"normal",
 	"quiet_denied",
 	"quiet",
···
 	"all"
 };
 
-static char *aa_audit_type[] = {
+static const char *const aa_audit_type[] = {
 	"AUDIT",
 	"ALLOWED",
 	"DENIED",
···
 	"STATUS",
 	"ERROR",
 	"KILLED"
+	"AUTO"
 };
 
 /*

security/apparmor/domain.c

···
 	state = profile->file.start;
 
 	/* buffer freed below, name is pointer into buffer */
-	error = aa_get_name(&bprm->file->f_path, profile->path_flags, &buffer,
-			    &name);
+	error = aa_path_name(&bprm->file->f_path, profile->path_flags, &buffer,
+			     &name, &info);
 	if (error) {
 		if (profile->flags &
 		    (PFLAG_IX_ON_NAME_ERROR | PFLAG_UNCONFINED))
 			error = 0;
-		info = "Exec failed name resolution";
 		name = bprm->filename;
 		goto audit;
 	}

security/apparmor/file.c

···
 	if (old & 0x40)	/* AA_EXEC_MMAP */
 		new |= AA_EXEC_MMAP;
 
-	new |= AA_MAY_META_READ;
-
 	return new;
 }
 
···
 		perms.quiet = map_old_perms(dfa_other_quiet(dfa, state));
 		perms.xindex = dfa_other_xindex(dfa, state);
 	}
+	perms.allow |= AA_MAY_META_READ;
 
 	/* change_profile wasn't determined by ownership in old mapping */
 	if (ACCEPT_TABLE(dfa)[state] & 0x80000000)
···
 	int error;
 
 	flags |= profile->path_flags | (S_ISDIR(cond->mode) ? PATH_IS_DIR : 0);
-	error = aa_get_name(path, flags, &buffer, &name);
+	error = aa_path_name(path, flags, &buffer, &name, &info);
 	if (error) {
 		if (error == -ENOENT && is_deleted(path->dentry)) {
 			/* Access to open files that are deleted are
 			 * give a pass (implicit delegation)
 			 */
 			error = 0;
+			info = NULL;
 			perms.allow = request;
-		} else if (error == -ENOENT)
-			info = "Failed name lookup - deleted entry";
-		else if (error == -ESTALE)
-			info = "Failed name lookup - disconnected path";
-		else if (error == -ENAMETOOLONG)
-			info = "Failed name lookup - name too long";
-		else
-			info = "Failed name lookup";
+		}
 	} else {
 		aa_str_perms(profile->file.dfa, profile->file.start, name, cond,
 			     &perms);
···
 	lperms = nullperms;
 
 	/* buffer freed below, lname is pointer in buffer */
-	error = aa_get_name(&link, profile->path_flags, &buffer, &lname);
+	error = aa_path_name(&link, profile->path_flags, &buffer, &lname,
+			     &info);
 	if (error)
 		goto audit;
 
 	/* buffer2 freed below, tname is pointer in buffer2 */
-	error = aa_get_name(&target, profile->path_flags, &buffer2, &tname);
+	error = aa_path_name(&target, profile->path_flags, &buffer2, &tname,
+			     &info);
 	if (error)
 		goto audit;
 

security/apparmor/include/apparmor.h

···
 
 #include "match.h"
 
+/*
+ * Class of mediation types in the AppArmor policy db
+ */
+#define AA_CLASS_ENTRY		0
+#define AA_CLASS_UNKNOWN	1
+#define AA_CLASS_FILE		2
+#define AA_CLASS_CAP		3
+#define AA_CLASS_NET		4
+#define AA_CLASS_RLIMITS	5
+#define AA_CLASS_DOMAIN		6
+
+#define AA_CLASS_LAST		AA_CLASS_DOMAIN
+
 /* Control parameters settable through module/boot flags */
 extern enum audit_mode aa_g_audit;
 extern bool aa_g_audit_header;
···
 						  unsigned int start)
 {
 	/* the null transition only needs the string's null terminator byte */
-	return aa_dfa_match_len(dfa, start, "", 1);
+	return aa_dfa_next(dfa, start, 0);
 }
 
 static inline bool mediated_filesystem(struct inode *inode)

security/apparmor/include/apparmorfs.h

···
 #ifndef __AA_APPARMORFS_H
 #define __AA_APPARMORFS_H
 
+enum aa_fs_type {
+	AA_FS_TYPE_BOOLEAN,
+	AA_FS_TYPE_STRING,
+	AA_FS_TYPE_U64,
+	AA_FS_TYPE_FOPS,
+	AA_FS_TYPE_DIR,
+};
+
+struct aa_fs_entry;
+
+struct aa_fs_entry {
+	const char *name;
+	struct dentry *dentry;
+	umode_t mode;
+	enum aa_fs_type v_type;
+	union {
+		bool boolean;
+		char *string;
+		unsigned long u64;
+		struct aa_fs_entry *files;
+	} v;
+	const struct file_operations *file_ops;
+};
+
+extern const struct file_operations aa_fs_seq_file_ops;
+
+#define AA_FS_FILE_BOOLEAN(_name, _value) \
+	{ .name = (_name), .mode = 0444, \
+	  .v_type = AA_FS_TYPE_BOOLEAN, .v.boolean = (_value), \
+	  .file_ops = &aa_fs_seq_file_ops }
+#define AA_FS_FILE_STRING(_name, _value) \
+	{ .name = (_name), .mode = 0444, \
+	  .v_type = AA_FS_TYPE_STRING, .v.string = (_value), \
+	  .file_ops = &aa_fs_seq_file_ops }
+#define AA_FS_FILE_U64(_name, _value) \
+	{ .name = (_name), .mode = 0444, \
+	  .v_type = AA_FS_TYPE_U64, .v.u64 = (_value), \
+	  .file_ops = &aa_fs_seq_file_ops }
+#define AA_FS_FILE_FOPS(_name, _mode, _fops) \
+	{ .name = (_name), .v_type = AA_FS_TYPE_FOPS, \
+	  .mode = (_mode), .file_ops = (_fops) }
+#define AA_FS_DIR(_name, _value) \
+	{ .name = (_name), .v_type = AA_FS_TYPE_DIR, .v.files = (_value) }
+
 extern void __init aa_destroy_aafs(void);
 
 #endif /* __AA_APPARMORFS_H */

security/apparmor/include/audit.h

···
 
 struct aa_profile;
 
-extern const char *audit_mode_names[];
+extern const char *const audit_mode_names[];
 #define AUDIT_MAX_INDEX 5
-
-#define AUDIT_APPARMOR_AUTO 0	/* auto choose audit message type */
 
 enum audit_mode {
 	AUDIT_NORMAL,		/* follow normal auditing of accesses */
···
 	AUDIT_APPARMOR_HINT,
 	AUDIT_APPARMOR_STATUS,
 	AUDIT_APPARMOR_ERROR,
-	AUDIT_APPARMOR_KILL
+	AUDIT_APPARMOR_KILL,
+	AUDIT_APPARMOR_AUTO
 };
 
-extern const char *op_table[];
+extern const char *const op_table[];
 enum aa_ops {
 	OP_NULL,
 

security/apparmor/include/file.h

···
 		index |= AA_X_NAME;
 	} else if (old_index == 3) {
 		index |= AA_X_NAME | AA_X_CHILD;
-	} else {
+	} else if (old_index) {
 		index |= AA_X_TABLE;
 		index |= old_index - 4;
 	}

security/apparmor/include/match.h

···
 			      const char *str, int len);
 unsigned int aa_dfa_match(struct aa_dfa *dfa, unsigned int start,
 			  const char *str);
+unsigned int aa_dfa_next(struct aa_dfa *dfa, unsigned int state,
+			 const char c);
+
 void aa_dfa_free_kref(struct kref *kref);
 
 /**

security/apparmor/include/path.h

···
 	PATH_MEDIATE_DELETED = 0x10000,	/* mediate deleted paths */
 };
 
-int aa_get_name(struct path *path, int flags, char **buffer, const char **name);
+int aa_path_name(struct path *path, int flags, char **buffer,
+		 const char **name, const char **info);
 
 #endif /* __AA_PATH_H */

security/apparmor/include/policy.h

···
 #include "file.h"
 #include "resource.h"
 
-extern const char *profile_mode_names[];
+extern const char *const profile_mode_names[];
 #define APPARMOR_NAMES_MAX_INDEX 3
 
 #define COMPLAIN_MODE(_profile)	\
···
 	struct list_head sub_ns;
 };
 
+/* struct aa_policydb - match engine for a policy
+ * dfa: dfa pattern match
+ * start: set of start states for the different classes of data
+ */
+struct aa_policydb {
+	/* Generic policy DFA specific rule types will be subsections of it */
+	struct aa_dfa *dfa;
+	unsigned int start[AA_CLASS_LAST + 1];
+
+};
+
 /* struct aa_profile - basic confinement data
  * @base - base components of the profile (name, refcount, lists, lock ...)
  * @parent: parent of profile
···
  * @flags: flags controlling profile behavior
  * @path_flags: flags controlling path generation behavior
  * @size: the memory consumed by this profiles rules
+ * @policy: general match rules governing policy
  * @file: The set of rules governing basic file access and domain transitions
  * @caps: capabilities for the profile
  * @rlimits: rlimits for the profile
···
 	u32 path_flags;
 	int size;
 
+	struct aa_policydb policy;
 	struct aa_file_rules file;
 	struct aa_caps caps;
 	struct aa_rlimit rlimits;

security/apparmor/include/resource.h

···
 #include <linux/resource.h>
 #include <linux/sched.h>
 
+#include "apparmorfs.h"
+
 struct aa_profile;
 
 /* struct aa_rlimit - rlimit settings for the profile
···
 	unsigned int mask;
 	struct rlimit limits[RLIM_NLIMITS];
 };
+
+extern struct aa_fs_entry aa_fs_entry_rlimit[];
 
 int aa_map_resource(int resource);
 int aa_task_setrlimit(struct aa_profile *profile, struct task_struct *,

security/apparmor/match.c

···
 }
 
 /**
- * aa_dfa_next_state - traverse @dfa to find state @str stops at
+ * aa_dfa_match - traverse @dfa to find state @str stops at
  * @dfa: the dfa to match @str against  (NOT NULL)
  * @start: the state of the dfa to start matching in
  * @str: the null terminated string of bytes to match against the dfa (NOT NULL)
  *
- * aa_dfa_next_state will match @str against the dfa and return the state it
+ * aa_dfa_match will match @str against the dfa and return the state it
  * finished matching in. The final state can be used to look up the accepting
  * label, or as the start state of a continuing match.
  *
···
 unsigned int aa_dfa_match(struct aa_dfa *dfa, unsigned int start,
 			  const char *str)
 {
-	return aa_dfa_match_len(dfa, start, str, strlen(str));
+	u16 *def = DEFAULT_TABLE(dfa);
+	u32 *base = BASE_TABLE(dfa);
+	u16 *next = NEXT_TABLE(dfa);
+	u16 *check = CHECK_TABLE(dfa);
+	unsigned int state = start, pos;
+
+	if (state == 0)
+		return 0;
+
+	/* current state is <state>, matching character *str */
+	if (dfa->tables[YYTD_ID_EC]) {
+		/* Equivalence class table defined */
+		u8 *equiv = EQUIV_TABLE(dfa);
+		/* default is direct to next state */
+		while (*str) {
+			pos = base[state] + equiv[(u8) *str++];
+			if (check[pos] == state)
+				state = next[pos];
+			else
+				state = def[state];
+		}
+	} else {
+		/* default is direct to next state */
+		while (*str) {
+			pos = base[state] + (u8) *str++;
+			if (check[pos] == state)
+				state = next[pos];
+			else
+				state = def[state];
+		}
+	}
+
+	return state;
+}
+
+/**
+ * aa_dfa_next - step one character to the next state in the dfa
+ * @dfa: the dfa to tranverse (NOT NULL)
+ * @state: the state to start in
+ * @c: the input character to transition on
+ *
+ * aa_dfa_match will step through the dfa by one input character @c
+ *
+ * Returns: state reach after input @c
+ */
+unsigned int aa_dfa_next(struct aa_dfa *dfa, unsigned int state,
+			  const char c)
+{
+	u16 *def = DEFAULT_TABLE(dfa);
+	u32 *base = BASE_TABLE(dfa);
+	u16 *next = NEXT_TABLE(dfa);
+	u16 *check = CHECK_TABLE(dfa);
+	unsigned int pos;
+
+	/* current state is <state>, matching character *str */
+	if (dfa->tables[YYTD_ID_EC]) {
+		/* Equivalence class table defined */
+		u8 *equiv = EQUIV_TABLE(dfa);
+		/* default is direct to next state */
+
+		pos = base[state] + equiv[(u8) c];
+		if (check[pos] == state)
+			state = next[pos];
+		else
+			state = def[state];
+	} else {
+		/* default is direct to next state */
+		pos = base[state] + (u8) c;
+		if (check[pos] == state)
+			state = next[pos];
+		else
+			state = def[state];
+	}
+
+	return state;
 }

security/apparmor/path.c

···
 		struct path root;
 		get_fs_root(current->fs, &root);
 		res = __d_path(path, &root, buf, buflen);
-		if (res && !IS_ERR(res)) {
-			/* everything's fine */
-			*name = res;
-			path_put(&root);
-			goto ok;
-		}
 		path_put(&root);
-		connected = 0;
+	} else {
+		res = d_absolute_path(path, buf, buflen);
+		if (!our_mnt(path->mnt))
+			connected = 0;
 	}
 
-	res = d_absolute_path(path, buf, buflen);
-
-	*name = res;
 	/* handle error conditions - and still allow a partial path to
 	 * be returned.
 	 */
-	if (IS_ERR(res)) {
-		error = PTR_ERR(res);
-		*name = buf;
-		goto out;
-	}
-	if (!our_mnt(path->mnt))
+	if (!res || IS_ERR(res)) {
+		connected = 0;
+		res = dentry_path_raw(path->dentry, buf, buflen);
+		if (IS_ERR(res)) {
+			error = PTR_ERR(res);
+			*name = buf;
+			goto out;
+		};
+	} else if (!our_mnt(path->mnt))
 		connected = 0;
 
-ok:
+	*name = res;
+
 	/* Handle two cases:
 	 * 1. A deleted dentry && profile is not allowing mediation of deleted
 	 * 2. On some filesystems, newly allocated dentries appear to the
···
 			/* disconnected path, don't return pathname starting
 			 * with '/'
 			 */
-			error = -ESTALE;
+			error = -EACCES;
 			if (*res == '/')
 				*name = res + 1;
 		}
···
  * Returns: %0 else error on failure
  */
 static int get_name_to_buffer(struct path *path, int flags, char *buffer,
-			      int size, char **name)
+			      int size, char **name, const char **info)
 {
 	int adjust = (flags & PATH_IS_DIR) ? 1 : 0;
 	int error = d_namespace_path(path, buffer, size - adjust, name, flags);
···
 		 */
 		strcpy(&buffer[size - 2], "/");
 
+	if (info && error) {
+		if (error == -ENOENT)
+			*info = "Failed name lookup - deleted entry";
+		else if (error == -ESTALE)
+			*info = "Failed name lookup - disconnected path";
+		else if (error == -ENAMETOOLONG)
+			*info = "Failed name lookup - name too long";
+		else
+			*info = "Failed name lookup";
+	}
+
 	return error;
 }
 
 /**
- * aa_get_name - compute the pathname of a file
+ * aa_path_name - compute the pathname of a file
  * @path: path the file  (NOT NULL)
  * @flags: flags controlling path name generation
  * @buffer: buffer that aa_get_name() allocated  (NOT NULL)
  * @name: Returns - the generated path name if !error (NOT NULL)
+ * @info: Returns - information on why the path lookup failed (MAYBE NULL)
  *
  * @name is a pointer to the beginning of the pathname (which usually differs
  * from the beginning of the buffer), or NULL.  If there is an error @name
···
  *
  * Returns: %0 else error code if could retrieve name
  */
-int aa_get_name(struct path *path, int flags, char **buffer, const char **name)
+int aa_path_name(struct path *path, int flags, char **buffer, const char **name,
+		 const char **info)
 {
 	char *buf, *str = NULL;
 	int size = 256;
···
 		if (!buf)
 			return -ENOMEM;
 
-		error = get_name_to_buffer(path, flags, buf, size, &str);
+		error = get_name_to_buffer(path, flags, buf, size, &str, info);
 		if (error != -ENAMETOOLONG)
 			break;
 
···
 		size <<= 1;
 		if (size > aa_g_path_max)
 			return -ENAMETOOLONG;
+		*info = NULL;
 	}
 	*buffer = buf;
 	*name = str;

security/apparmor/policy.c

···
 /* root profile namespace */
 struct aa_namespace *root_ns;
 
-const char *profile_mode_names[] = {
+const char *const profile_mode_names[] = {
 	"enforce",
 	"complain",
 	"kill",
···
 
 	aa_free_sid(profile->sid);
 	aa_put_dfa(profile->xmatch);
+	aa_put_dfa(profile->policy.dfa);
 
 	aa_put_profile(profile->replacedby);
 

security/apparmor/policy_unpack.c

···
  * @new: profile if it has been allocated (MAYBE NULL)
  * @name: name of the profile being manipulated (MAYBE NULL)
  * @info: any extra info about the failure (MAYBE NULL)
- * @e: buffer position info (NOT NULL)
+ * @e: buffer position info
  * @error: error code
  *
  * Returns: %0 or error
···
 	struct aa_profile *profile = __aa_current_profile();
 	struct common_audit_data sa;
 	COMMON_AUDIT_DATA_INIT(&sa, NONE);
-	sa.aad.iface.pos = e->pos - e->start;
+	if (e)
+		sa.aad.iface.pos = e->pos - e->start;
 	sa.aad.iface.target = new;
 	sa.aad.name = name;
 	sa.aad.info = info;
···
 {
 	struct aa_profile *profile = NULL;
 	const char *name = NULL;
-	int error = -EPROTO;
+	int i, error = -EPROTO;
 	kernel_cap_t tmpcap;
 	u32 tmp;
 
···
 			goto fail;
 		if (!unpack_u32(e, &(profile->caps.extended.cap[1]), NULL))
 			goto fail;
+		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
+			goto fail;
 	}
 
 	if (!unpack_rlimits(e, profile))
 		goto fail;
+
+	if (unpack_nameX(e, AA_STRUCT, "policydb")) {
+		/* generic policy dfa - optional and may be NULL */
+		profile->policy.dfa = unpack_dfa(e);
+		if (IS_ERR(profile->policy.dfa)) {
+			error = PTR_ERR(profile->policy.dfa);
+			profile->policy.dfa = NULL;
+			goto fail;
+		}
+		if (!unpack_u32(e, &profile->policy.start[0], "start"))
+			/* default start state */
+			profile->policy.start[0] = DFA_START;
+		/* setup class index */
+		for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) {
+			profile->policy.start[i] =
+				aa_dfa_next(profile->policy.dfa,
+					    profile->policy.start[0],
+					    i);
+		}
+		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
+			goto fail;
+	}
 
 	/* get file rules */
 	profile->file.dfa = unpack_dfa(e);

security/apparmor/resource.c

···
  */
 #include "rlim_names.h"
 
+struct aa_fs_entry aa_fs_entry_rlimit[] = {
+	AA_FS_FILE_STRING("mask", AA_FS_RLIMIT_MASK),
+	{ }
+};
+
 /* audit callback for resource specific fields */
 static void audit_cb(struct audit_buffer *ab, void *va)
 {

security/capability.c

···
 	return 0;
 }
 
+static void cap_task_free(struct task_struct *task)
+{
+}
+
 static int cap_cred_alloc_blank(struct cred *cred, gfp_t gfp)
 {
 	return 0;
···
 	set_to_cap_if_null(ops, file_receive);
 	set_to_cap_if_null(ops, dentry_open);
 	set_to_cap_if_null(ops, task_create);
+	set_to_cap_if_null(ops, task_free);
 	set_to_cap_if_null(ops, cred_alloc_blank);
 	set_to_cap_if_null(ops, cred_free);
 	set_to_cap_if_null(ops, cred_prepare);

security/commoncap.c

···
 #include <linux/prctl.h>
 #include <linux/securebits.h>
 #include <linux/user_namespace.h>
+#include <linux/binfmts.h>
 
 /*
  * If a non-root user executes a setuid-root binary in

security/integrity/ima/Kconfig

···
 	select CRYPTO_HMAC
 	select CRYPTO_MD5
 	select CRYPTO_SHA1
-	select TCG_TPM if !S390 && !UML
-	select TCG_TIS if TCG_TPM
+	select TCG_TPM if HAS_IOMEM && !UML
+	select TCG_TIS if TCG_TPM && X86
 	help
 	  The Trusted Computing Group(TCG) runtime Integrity
 	  Measurement Architecture(IMA) maintains a list of hash

security/integrity/ima/ima_audit.c

···
 		audit_log_untrustedstring(ab, inode->i_sb->s_id);
 		audit_log_format(ab, " ino=%lu", inode->i_ino);
 	}
-	audit_log_format(ab, " res=%d", !result ? 0 : 1);
+	audit_log_format(ab, " res=%d", !result);
 	audit_log_end(ab);
 }

security/integrity/ima/ima_policy.c

···
 	{.action = DONT_MEASURE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC},
 	{.action = DONT_MEASURE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC},
 	{.action = DONT_MEASURE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_MEASURE,.fsmagic = RAMFS_MAGIC,.flags = IMA_FSMAGIC},
 	{.action = DONT_MEASURE,.fsmagic = SECURITYFS_MAGIC,.flags = IMA_FSMAGIC},
 	{.action = DONT_MEASURE,.fsmagic = SELINUX_MAGIC,.flags = IMA_FSMAGIC},
 	{.action = MEASURE,.func = FILE_MMAP,.mask = MAY_EXEC,
···
 	if (!result && (entry->action == UNKNOWN))
 		result = -EINVAL;
 
-	audit_log_format(ab, "res=%d", !!result);
+	audit_log_format(ab, "res=%d", !result);
 	audit_log_end(ab);
 	return result;
 }

security/keys/keyctl.c

···
 	keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
 	if (IS_ERR(keyring_ref)) {
 		ret = PTR_ERR(keyring_ref);
+
+		/* Root is permitted to invalidate certain special keyrings */
+		if (capable(CAP_SYS_ADMIN)) {
+			keyring_ref = lookup_user_key(ringid, 0, 0);
+			if (IS_ERR(keyring_ref))
+				goto error;
+			if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR,
+				     &key_ref_to_ptr(keyring_ref)->flags))
+				goto clear;
+			goto error_put;
+		}
+
 		goto error;
 	}
 
+clear:
 	ret = keyring_clear(key_ref_to_ptr(keyring_ref));
-
+error_put:
 	key_ref_put(keyring_ref);
 error:
 	return ret;

security/keys/process_keys.c

···
 			goto error;
 
 		down_read(&cred->request_key_auth->sem);
-		if (cred->request_key_auth->flags & KEY_FLAG_REVOKED) {
+		if (test_bit(KEY_FLAG_REVOKED,
+			     &cred->request_key_auth->flags)) {
 			key_ref = ERR_PTR(-EKEYREVOKED);
 			key = NULL;
 		} else {

security/security.c

···
 #include <linux/integrity.h>
 #include <linux/ima.h>
 #include <linux/evm.h>
+#include <linux/fsnotify.h>
+#include <net/flow.h>
 
 #define MAX_LSM_EVM_XATTR	2
 
···
 	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)
···
 int security_task_create(unsigned long clone_flags)
 {
 	return security_ops->task_create(clone_flags);
+}
+
+void security_task_free(struct task_struct *task)
+{
+	security_ops->task_free(task);
 }
 
 int security_cred_alloc_blank(struct cred *cred, gfp_t gfp)

security/selinux/hooks.c

···
 #include <linux/syslog.h>
 #include <linux/user_namespace.h>
 #include <linux/export.h>
+#include <linux/msg.h>
+#include <linux/shm.h>
 
 #include "avc.h"
 #include "objsec.h"

security/smack/smack_lsm.c

···
 #include <linux/magic.h>
 #include <linux/dcache.h>
 #include <linux/personality.h>
+#include <linux/msg.h>
+#include <linux/shm.h>
+#include <linux/binfmts.h>
 #include "smack.h"
 
 #define task_security(task)	(task_cred_xxx((task), security))

security/tomoyo/audit.c

···
  * tomoyo_poll_log - Wait for an audit log.
  *
  * @file: Pointer to "struct file".
- * @wait: Pointer to "poll_table".
+ * @wait: Pointer to "poll_table". Maybe NULL.
  *
  * Returns POLLIN | POLLRDNORM when ready to read an audit log.
  */
-int tomoyo_poll_log(struct file *file, poll_table *wait)
+unsigned int tomoyo_poll_log(struct file *file, poll_table *wait)
 {
 	if (tomoyo_log_count)
 		return POLLIN | POLLRDNORM;

security/tomoyo/common.c

···
  *
  * @domainname: The name of domain.
  *
- * Returns 0.
+ * Returns 0 on success, negative value otherwise.
  *
  * Caller holds tomoyo_read_lock().
  */
···
 	name.name = domainname;
 	tomoyo_fill_path_info(&name);
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
-		return 0;
+		return -EINTR;
 	/* Is there an active domain? */
 	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
 		/* Never delete tomoyo_kernel_domain */
···
 	bool is_select = !is_delete && tomoyo_str_starts(&data, "select ");
 	unsigned int profile;
 	if (*data == '<') {
+		int ret = 0;
 		domain = NULL;
 		if (is_delete)
-			tomoyo_delete_domain(data);
+			ret = tomoyo_delete_domain(data);
 		else if (is_select)
 			domain = tomoyo_find_domain(data);
 		else
 			domain = tomoyo_assign_domain(data, false);
 		head->w.domain = domain;
-		return 0;
+		return ret;
 	}
 	if (!domain)
 		return -EINVAL;
···
 	struct tomoyo_domain_info *domain = NULL;
 	spin_lock(&tomoyo_query_list_lock);
 	list_for_each_entry(ptr, &tomoyo_query_list, list) {
-		if (ptr->serial != serial || ptr->answer)
+		if (ptr->serial != serial)
 			continue;
 		domain = ptr->domain;
 		break;
···
  *
  * Waits for access requests which violated policy in enforcing mode.
  */
-static int tomoyo_poll_query(struct file *file, poll_table *wait)
+static unsigned int tomoyo_poll_query(struct file *file, poll_table *wait)
 {
-	struct list_head *tmp;
-	bool found = false;
-	u8 i;
-	for (i = 0; i < 2; i++) {
-		spin_lock(&tomoyo_query_list_lock);
-		list_for_each(tmp, &tomoyo_query_list) {
-			struct tomoyo_query *ptr =
-				list_entry(tmp, typeof(*ptr), list);
-			if (ptr->answer)
-				continue;
-			found = true;
-			break;
-		}
-		spin_unlock(&tomoyo_query_list_lock);
-		if (found)
-			return POLLIN | POLLRDNORM;
-		if (i)
-			break;
-		poll_wait(file, &tomoyo_query_wait, wait);
-	}
+	if (!list_empty(&tomoyo_query_list))
+		return POLLIN | POLLRDNORM;
+	poll_wait(file, &tomoyo_query_wait, wait);
+	if (!list_empty(&tomoyo_query_list))
+		return POLLIN | POLLRDNORM;
 	return 0;
 }
 
···
 	spin_lock(&tomoyo_query_list_lock);
 	list_for_each(tmp, &tomoyo_query_list) {
 		struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
-		if (ptr->answer)
-			continue;
 		if (pos++ != head->r.query_index)
 			continue;
 		len = ptr->query_len;
···
 	spin_lock(&tomoyo_query_list_lock);
 	list_for_each(tmp, &tomoyo_query_list) {
 		struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
-		if (ptr->answer)
-			continue;
 		if (pos++ != head->r.query_index)
 			continue;
 		/*
···
 		struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
 		if (ptr->serial != serial)
 			continue;
-		if (!ptr->answer)
-			ptr->answer = answer;
+		ptr->answer = answer;
+		/* Remove from tomoyo_query_list. */
+		if (ptr->answer)
+			list_del_init(&ptr->list);
 		break;
 	}
 	spin_unlock(&tomoyo_query_list_lock);
···
  * tomoyo_poll_control - poll() for /sys/kernel/security/tomoyo/ interface.
  *
  * @file: Pointer to "struct file".
- * @wait: Pointer to "poll_table".
+ * @wait: Pointer to "poll_table". Maybe NULL.
  *
- * Waits for read readiness.
- * /sys/kernel/security/tomoyo/query is handled by /usr/sbin/tomoyo-queryd and
- * /sys/kernel/security/tomoyo/audit is handled by /usr/sbin/tomoyo-auditd.
+ * Returns POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM if ready to read/write,
+ * POLLOUT | POLLWRNORM otherwise.
  */
-int tomoyo_poll_control(struct file *file, poll_table *wait)
+unsigned int tomoyo_poll_control(struct file *file, poll_table *wait)
 {
 	struct tomoyo_io_buffer *head = file->private_data;
-	if (!head->poll)
-		return -ENOSYS;
-	return head->poll(file, wait);
+	if (head->poll)
+		return head->poll(file, wait) | POLLOUT | POLLWRNORM;
+	return POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM;
 }
 
 /**

security/tomoyo/common.h

···
 struct tomoyo_io_buffer {
 	void (*read) (struct tomoyo_io_buffer *);
 	int (*write) (struct tomoyo_io_buffer *);
-	int (*poll) (struct file *file, poll_table *wait);
+	unsigned int (*poll) (struct file *file, poll_table *wait);
 	/* Exclusive lock for this structure.   */
 	struct mutex io_sem;
 	char __user *read_user_buf;
···
 			    unsigned long number);
 int tomoyo_path_perm(const u8 operation, struct path *path,
 		     const char *target);
-int tomoyo_poll_control(struct file *file, poll_table *wait);
-int tomoyo_poll_log(struct file *file, poll_table *wait);
+unsigned int tomoyo_poll_control(struct file *file, poll_table *wait);
+unsigned int tomoyo_poll_log(struct file *file, poll_table *wait);
 int tomoyo_socket_bind_permission(struct socket *sock, struct sockaddr *addr,
 				  int addr_len);
 int tomoyo_socket_connect_permission(struct socket *sock,

security/tomoyo/mount.c

···
 	if (flags & MS_REMOUNT) {
 		type = tomoyo_mounts[TOMOYO_MOUNT_REMOUNT];
 		flags &= ~MS_REMOUNT;
-	}
-	if (flags & MS_MOVE) {
-		type = tomoyo_mounts[TOMOYO_MOUNT_MOVE];
-		flags &= ~MS_MOVE;
-	}
-	if (flags & MS_BIND) {
+	} else if (flags & MS_BIND) {
 		type = tomoyo_mounts[TOMOYO_MOUNT_BIND];
 		flags &= ~MS_BIND;
-	}
-	if (flags & MS_UNBINDABLE) {
-		type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_UNBINDABLE];
-		flags &= ~MS_UNBINDABLE;
-	}
-	if (flags & MS_PRIVATE) {
-		type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_PRIVATE];
-		flags &= ~MS_PRIVATE;
-	}
-	if (flags & MS_SLAVE) {
-		type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SLAVE];
-		flags &= ~MS_SLAVE;
-	}
-	if (flags & MS_SHARED) {
+	} else if (flags & MS_SHARED) {
+		if (flags & (MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE))
+			return -EINVAL;
 		type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SHARED];
 		flags &= ~MS_SHARED;
+	} else if (flags & MS_PRIVATE) {
+		if (flags & (MS_SHARED | MS_SLAVE | MS_UNBINDABLE))
+			return -EINVAL;
+		type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_PRIVATE];
+		flags &= ~MS_PRIVATE;
+	} else if (flags & MS_SLAVE) {
+		if (flags & (MS_SHARED | MS_PRIVATE | MS_UNBINDABLE))
+			return -EINVAL;
+		type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SLAVE];
+		flags &= ~MS_SLAVE;
+	} else if (flags & MS_UNBINDABLE) {
+		if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE))
+			return -EINVAL;
+		type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_UNBINDABLE];
+		flags &= ~MS_UNBINDABLE;
+	} else if (flags & MS_MOVE) {
+		type = tomoyo_mounts[TOMOYO_MOUNT_MOVE];
+		flags &= ~MS_MOVE;
 	}
 	if (!type)
 		type = "<NULL>";

security/tomoyo/securityfs_if.c

···
  * tomoyo_poll - poll() for /sys/kernel/security/tomoyo/ interface.
  *
  * @file: Pointer to "struct file".
- * @wait: Pointer to "poll_table".
+ * @wait: Pointer to "poll_table". Maybe NULL.
  *
- * Returns 0 on success, negative value otherwise.
+ * Returns POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM if ready to read/write,
+ * POLLOUT | POLLWRNORM otherwise.
  */
 static unsigned int tomoyo_poll(struct file *file, poll_table *wait)
 {

security/yama/Kconfig

···
+config SECURITY_YAMA
+	bool "Yama support"
+	depends on SECURITY
+	select SECURITYFS
+	select SECURITY_PATH
+	default n
+	help
+	  This selects Yama, which extends DAC support with additional
+	  system-wide security settings beyond regular Linux discretionary
+	  access controls. Currently available is ptrace scope restriction.
+	  Further information can be found in Documentation/security/Yama.txt.
+
+	  If you are unsure how to answer this question, answer N.

security/yama/Makefile

···
+obj-$(CONFIG_SECURITY_YAMA) := yama.o
+
+yama-y := yama_lsm.o

security/yama/yama_lsm.c

···
+/*
+ * Yama Linux Security Module
+ *
+ * Author: Kees Cook <[e-mail]>
+ *
+ * Copyright (C) 2010 Canonical, Ltd.
+ * Copyright (C) 2011 The Chromium OS Authors.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/security.h>
+#include <linux/sysctl.h>
+#include <linux/ptrace.h>
+#include <linux/prctl.h>
+#include <linux/ratelimit.h>
+
+static int ptrace_scope = 1;
+
+/* describe a ptrace relationship for potential exception */
+struct ptrace_relation {
+	struct task_struct *tracer;
+	struct task_struct *tracee;
+	struct list_head node;
+};
+
+static LIST_HEAD(ptracer_relations);
+static DEFINE_SPINLOCK(ptracer_relations_lock);
+
+/**
+ * yama_ptracer_add - add/replace an exception for this tracer/tracee pair
+ * @tracer: the task_struct of the process doing the ptrace
+ * @tracee: the task_struct of the process to be ptraced
+ *
+ * Each tracee can have, at most, one tracer registered. Each time this
+ * is called, the prior registered tracer will be replaced for the tracee.
+ *
+ * Returns 0 if relationship was added, -ve on error.
+ */
+static int yama_ptracer_add(struct task_struct *tracer,
+			    struct task_struct *tracee)
+{
+	int rc = 0;
+	struct ptrace_relation *added;
+	struct ptrace_relation *entry, *relation = NULL;
+
+	added = kmalloc(sizeof(*added), GFP_KERNEL);
+	if (!added)
+		return -ENOMEM;
+
+	spin_lock_bh(&ptracer_relations_lock);
+	list_for_each_entry(entry, &ptracer_relations, node)
+		if (entry->tracee == tracee) {
+			relation = entry;
+			break;
+		}
+	if (!relation) {
+		relation = added;
+		relation->tracee = tracee;
+		list_add(&relation->node, &ptracer_relations);
+	}
+	relation->tracer = tracer;
+
+	spin_unlock_bh(&ptracer_relations_lock);
+	if (added != relation)
+		kfree(added);
+
+	return rc;
+}
+
+/**
+ * yama_ptracer_del - remove exceptions related to the given tasks
+ * @tracer: remove any relation where tracer task matches
+ * @tracee: remove any relation where tracee task matches
+ */
+static void yama_ptracer_del(struct task_struct *tracer,
+			     struct task_struct *tracee)
+{
+	struct ptrace_relation *relation, *safe;
+
+	spin_lock_bh(&ptracer_relations_lock);
+	list_for_each_entry_safe(relation, safe, &ptracer_relations, node)
+		if (relation->tracee == tracee ||
+		    (tracer && relation->tracer == tracer)) {
+			list_del(&relation->node);
+			kfree(relation);
+		}
+	spin_unlock_bh(&ptracer_relations_lock);
+}
+
+/**
+ * yama_task_free - check for task_pid to remove from exception list
+ * @task: task being removed
+ */
+static void yama_task_free(struct task_struct *task)
+{
+	yama_ptracer_del(task, task);
+}
+
+/**
+ * yama_task_prctl - check for Yama-specific prctl operations
+ * @option: operation
+ * @arg2: argument
+ * @arg3: argument
+ * @arg4: argument
+ * @arg5: argument
+ *
+ * Return 0 on success, -ve on error.  -ENOSYS is returned when Yama
+ * does not handle the given option.
+ */
+static int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3,
+			   unsigned long arg4, unsigned long arg5)
+{
+	int rc;
+	struct task_struct *myself = current;
+
+	rc = cap_task_prctl(option, arg2, arg3, arg4, arg5);
+	if (rc != -ENOSYS)
+		return rc;
+
+	switch (option) {
+	case PR_SET_PTRACER:
+		/* Since a thread can call prctl(), find the group leader
+		 * before calling _add() or _del() on it, since we want
+		 * process-level granularity of control. The tracer group
+		 * leader checking is handled later when walking the ancestry
+		 * at the time of PTRACE_ATTACH check.
+		 */
+		rcu_read_lock();
+		if (!thread_group_leader(myself))
+			myself = rcu_dereference(myself->group_leader);
+		get_task_struct(myself);
+		rcu_read_unlock();
+
+		if (arg2 == 0) {
+			yama_ptracer_del(NULL, myself);
+			rc = 0;
+		} else if (arg2 == PR_SET_PTRACER_ANY) {
+			rc = yama_ptracer_add(NULL, myself);
+		} else {
+			struct task_struct *tracer;
+
+			rcu_read_lock();
+			tracer = find_task_by_vpid(arg2);
+			if (tracer)
+				get_task_struct(tracer);
+			else
+				rc = -EINVAL;
+			rcu_read_unlock();
+
+			if (tracer) {
+				rc = yama_ptracer_add(tracer, myself);
+				put_task_struct(tracer);
+			}
+		}
+
+		put_task_struct(myself);
+		break;
+	}
+
+	return rc;
+}
+
+/**
+ * task_is_descendant - walk up a process family tree looking for a match
+ * @parent: the process to compare against while walking up from child
+ * @child: the process to start from while looking upwards for parent
+ *
+ * Returns 1 if child is a descendant of parent, 0 if not.
+ */
+static int task_is_descendant(struct task_struct *parent,
+			      struct task_struct *child)
+{
+	int rc = 0;
+	struct task_struct *walker = child;
+
+	if (!parent || !child)
+		return 0;
+
+	rcu_read_lock();
+	if (!thread_group_leader(parent))
+		parent = rcu_dereference(parent->group_leader);
+	while (walker->pid > 0) {
+		if (!thread_group_leader(walker))
+			walker = rcu_dereference(walker->group_leader);
+		if (walker == parent) {
+			rc = 1;
+			break;
+		}
+		walker = rcu_dereference(walker->real_parent);
+	}
+	rcu_read_unlock();
+
+	return rc;
+}
+
+/**
+ * ptracer_exception_found - tracer registered as exception for this tracee
+ * @tracer: the task_struct of the process attempting ptrace
+ * @tracee: the task_struct of the process to be ptraced
+ *
+ * Returns 1 if tracer has is ptracer exception ancestor for tracee.
+ */
+static int ptracer_exception_found(struct task_struct *tracer,
+				   struct task_struct *tracee)
+{
+	int rc = 0;
+	struct ptrace_relation *relation;
+	struct task_struct *parent = NULL;
+	bool found = false;
+
+	spin_lock_bh(&ptracer_relations_lock);
+	rcu_read_lock();
+	if (!thread_group_leader(tracee))
+		tracee = rcu_dereference(tracee->group_leader);
+	list_for_each_entry(relation, &ptracer_relations, node)
+		if (relation->tracee == tracee) {
+			parent = relation->tracer;
+			found = true;
+			break;
+		}
+
+	if (found && (parent == NULL || task_is_descendant(parent, tracer)))
+		rc = 1;
+	rcu_read_unlock();
+	spin_unlock_bh(&ptracer_relations_lock);
+
+	return rc;
+}
+
+/**
+ * yama_ptrace_access_check - validate PTRACE_ATTACH calls
+ * @child: task that current task is attempting to ptrace
+ * @mode: ptrace attach mode
+ *
+ * Returns 0 if following the ptrace is allowed, -ve on error.
+ */
+static int yama_ptrace_access_check(struct task_struct *child,
+				    unsigned int mode)
+{
+	int rc;
+
+	/* If standard caps disallows it, so does Yama.  We should
+	 * only tighten restrictions further.
+	 */
+	rc = cap_ptrace_access_check(child, mode);
+	if (rc)
+		return rc;
+
+	/* require ptrace target be a child of ptracer on attach */
+	if (mode == PTRACE_MODE_ATTACH &&
+	    ptrace_scope &&
+	    !task_is_descendant(current, child) &&
+	    !ptracer_exception_found(current, child) &&
+	    !capable(CAP_SYS_PTRACE))
+		rc = -EPERM;
+
+	if (rc) {
+		char name[sizeof(current->comm)];
+		printk_ratelimited(KERN_NOTICE "ptrace of non-child"
+			" pid %d was attempted by: %s (pid %d)\n",
+			child->pid,
+			get_task_comm(name, current),
+			current->pid);
+	}
+
+	return rc;
+}
+
+static struct security_operations yama_ops = {
+	.name =			"yama",
+
+	.ptrace_access_check =	yama_ptrace_access_check,
+	.task_prctl =		yama_task_prctl,
+	.task_free =		yama_task_free,
+};
+
+#ifdef CONFIG_SYSCTL
+static int zero;
+static int one = 1;
+
+struct ctl_path yama_sysctl_path[] = {
+	{ .procname = "kernel", },
+	{ .procname = "yama", },
+	{ }
+};
+
+static struct ctl_table yama_sysctl_table[] = {
+	{
+		.procname       = "ptrace_scope",
+		.data           = &ptrace_scope,
+		.maxlen         = sizeof(int),
+		.mode           = 0644,
+		.proc_handler   = proc_dointvec_minmax,
+		.extra1         = &zero,
+		.extra2         = &one,
+	},
+	{ }
+};
+#endif /* CONFIG_SYSCTL */
+
+static __init int yama_init(void)
+{
+	if (!security_module_enable(&yama_ops))
+		return 0;
+
+	printk(KERN_INFO "Yama: becoming mindful.\n");
+
+	if (register_security(&yama_ops))
+		panic("Yama: kernel registration failed.\n");
+
+#ifdef CONFIG_SYSCTL
+	if (!register_sysctl_paths(yama_sysctl_path, yama_sysctl_table))
+		panic("Yama: sysctl registration failed.\n");
+#endif
+
+	return 0;
+}
+
+security_initcall(yama_init);