/* auditsc.c -- System-call auditing support

   * Handles all system-call specific auditing features.
   *
   * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.

   * Copyright 2005 Hewlett-Packard Development Company, L.P.

   * Copyright (C) 2005, 2006 IBM Corporation

   * All Rights Reserved.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   * Written by Rickard E. (Rik) Faith <faith@redhat.com>
   *
   * Many of the ideas implemented here are from Stephen C. Tweedie,
   * especially the idea of avoiding a copy by using getname.
   *
   * The method for actual interception of syscall entry and exit (not in
   * this file -- see entry.S) is based on a GPL'd patch written by
   * okir@suse.de and Copyright 2003 SuSE Linux AG.
   *

   * POSIX message queue support added by George Wilson <ltcgcw@us.ibm.com>,
   * 2006.
   *

   * The support of additional filter rules compares (>, <, >=, <=) was
   * added by Dustin Kirkland <dustin.kirkland@us.ibm.com>, 2005.
   *

   * Modified by Amy Griffis <amy.griffis@hp.com> to collect additional
   * filesystem information.

   *
   * Subject and object context labeling support added by <danjones@us.ibm.com>
   * and <dustin.kirkland@us.ibm.com> for LSPP certification compliance.

   */
  
  #include <linux/init.h>

  #include <asm/types.h>

  #include <linux/atomic.h>

  #include <linux/fs.h>
  #include <linux/namei.h>

  #include <linux/mm.h>

  #include <linux/export.h>

  #include <linux/slab.h>

  #include <linux/mount.h>

  #include <linux/socket.h>

  #include <linux/mqueue.h>

  #include <linux/audit.h>
  #include <linux/personality.h>
  #include <linux/time.h>

  #include <linux/netlink.h>

  #include <linux/compiler.h>

  #include <asm/unistd.h>

  #include <linux/security.h>

  #include <linux/list.h>

  #include <linux/tty.h>

  #include <linux/binfmts.h>

  #include <linux/highmem.h>

  #include <linux/syscalls.h>

  #include <linux/capability.h>

  #include <linux/fs_struct.h>

  #include <linux/compat.h>

  #include "audit.h"

  /* flags stating the success for a syscall */
  #define AUDITSC_INVALID 0
  #define AUDITSC_SUCCESS 1
  #define AUDITSC_FAILURE 2

  /* no execve audit message should be longer than this (userspace limits) */
  #define MAX_EXECVE_AUDIT_LEN 7500

  /* number of audit rules */
  int audit_n_rules;

  /* determines whether we collect data for signals sent */
  int audit_signals;

  struct audit_aux_data {
  	struct audit_aux_data	*next;
  	int			type;
  };
  
  #define AUDIT_AUX_IPCPERM	0

  /* Number of target pids per aux struct. */
  #define AUDIT_AUX_PIDS	16

  struct audit_aux_data_execve {
  	struct audit_aux_data	d;
  	int argc;
  	int envc;

  	struct mm_struct *mm;

  };

  struct audit_aux_data_pids {
  	struct audit_aux_data	d;
  	pid_t			target_pid[AUDIT_AUX_PIDS];

  	kuid_t			target_auid[AUDIT_AUX_PIDS];

  	kuid_t			target_uid[AUDIT_AUX_PIDS];

  	unsigned int		target_sessionid[AUDIT_AUX_PIDS];

  	u32			target_sid[AUDIT_AUX_PIDS];

  	char 			target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];

  	int			pid_count;
  };

  struct audit_aux_data_bprm_fcaps {
  	struct audit_aux_data	d;
  	struct audit_cap_data	fcap;
  	unsigned int		fcap_ver;
  	struct audit_cap_data	old_pcap;
  	struct audit_cap_data	new_pcap;
  };

  struct audit_aux_data_capset {
  	struct audit_aux_data	d;
  	pid_t			pid;
  	struct audit_cap_data	cap;
  };

  struct audit_tree_refs {
  	struct audit_tree_refs *next;
  	struct audit_chunk *c[31];
  };

  static inline int open_arg(int flags, int mask)
  {
  	int n = ACC_MODE(flags);
  	if (flags & (O_TRUNC | O_CREAT))
  		n |= AUDIT_PERM_WRITE;
  	return n & mask;
  }
  
  static int audit_match_perm(struct audit_context *ctx, int mask)
  {

  	unsigned n;

  	if (unlikely(!ctx))
  		return 0;

  	n = ctx->major;

  	switch (audit_classify_syscall(ctx->arch, n)) {
  	case 0:	/* native */
  		if ((mask & AUDIT_PERM_WRITE) &&
  		     audit_match_class(AUDIT_CLASS_WRITE, n))
  			return 1;
  		if ((mask & AUDIT_PERM_READ) &&
  		     audit_match_class(AUDIT_CLASS_READ, n))
  			return 1;
  		if ((mask & AUDIT_PERM_ATTR) &&
  		     audit_match_class(AUDIT_CLASS_CHATTR, n))
  			return 1;
  		return 0;
  	case 1: /* 32bit on biarch */
  		if ((mask & AUDIT_PERM_WRITE) &&
  		     audit_match_class(AUDIT_CLASS_WRITE_32, n))
  			return 1;
  		if ((mask & AUDIT_PERM_READ) &&
  		     audit_match_class(AUDIT_CLASS_READ_32, n))
  			return 1;
  		if ((mask & AUDIT_PERM_ATTR) &&
  		     audit_match_class(AUDIT_CLASS_CHATTR_32, n))
  			return 1;
  		return 0;
  	case 2: /* open */
  		return mask & ACC_MODE(ctx->argv[1]);
  	case 3: /* openat */
  		return mask & ACC_MODE(ctx->argv[2]);
  	case 4: /* socketcall */
  		return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND);
  	case 5: /* execve */
  		return mask & AUDIT_PERM_EXEC;
  	default:
  		return 0;
  	}
  }

  static int audit_match_filetype(struct audit_context *ctx, int val)

  {

  	struct audit_names *n;

  	umode_t mode = (umode_t)val;

  
  	if (unlikely(!ctx))
  		return 0;

  	list_for_each_entry(n, &ctx->names_list, list) {
  		if ((n->ino != -1) &&
  		    ((n->mode & S_IFMT) == mode))

  			return 1;
  	}

  	return 0;

  }

  /*
   * We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *;
   * ->first_trees points to its beginning, ->trees - to the current end of data.
   * ->tree_count is the number of free entries in array pointed to by ->trees.
   * Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL,
   * "empty" becomes (p, p, 31) afterwards.  We don't shrink the list (and seriously,
   * it's going to remain 1-element for almost any setup) until we free context itself.
   * References in it _are_ dropped - at the same time we free/drop aux stuff.
   */
  
  #ifdef CONFIG_AUDIT_TREE

  static void audit_set_auditable(struct audit_context *ctx)
  {
  	if (!ctx->prio) {
  		ctx->prio = 1;
  		ctx->current_state = AUDIT_RECORD_CONTEXT;
  	}
  }

  static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk)
  {
  	struct audit_tree_refs *p = ctx->trees;
  	int left = ctx->tree_count;
  	if (likely(left)) {
  		p->c[--left] = chunk;
  		ctx->tree_count = left;
  		return 1;
  	}
  	if (!p)
  		return 0;
  	p = p->next;
  	if (p) {
  		p->c[30] = chunk;
  		ctx->trees = p;
  		ctx->tree_count = 30;
  		return 1;
  	}
  	return 0;
  }
  
  static int grow_tree_refs(struct audit_context *ctx)
  {
  	struct audit_tree_refs *p = ctx->trees;
  	ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL);
  	if (!ctx->trees) {
  		ctx->trees = p;
  		return 0;
  	}
  	if (p)
  		p->next = ctx->trees;
  	else
  		ctx->first_trees = ctx->trees;
  	ctx->tree_count = 31;
  	return 1;
  }
  #endif
  
  static void unroll_tree_refs(struct audit_context *ctx,
  		      struct audit_tree_refs *p, int count)
  {
  #ifdef CONFIG_AUDIT_TREE
  	struct audit_tree_refs *q;
  	int n;
  	if (!p) {
  		/* we started with empty chain */
  		p = ctx->first_trees;
  		count = 31;
  		/* if the very first allocation has failed, nothing to do */
  		if (!p)
  			return;
  	}
  	n = count;
  	for (q = p; q != ctx->trees; q = q->next, n = 31) {
  		while (n--) {
  			audit_put_chunk(q->c[n]);
  			q->c[n] = NULL;
  		}
  	}
  	while (n-- > ctx->tree_count) {
  		audit_put_chunk(q->c[n]);
  		q->c[n] = NULL;
  	}
  	ctx->trees = p;
  	ctx->tree_count = count;
  #endif
  }
  
  static void free_tree_refs(struct audit_context *ctx)
  {
  	struct audit_tree_refs *p, *q;
  	for (p = ctx->first_trees; p; p = q) {
  		q = p->next;
  		kfree(p);
  	}
  }
  
  static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree)
  {
  #ifdef CONFIG_AUDIT_TREE
  	struct audit_tree_refs *p;
  	int n;
  	if (!tree)
  		return 0;
  	/* full ones */
  	for (p = ctx->first_trees; p != ctx->trees; p = p->next) {
  		for (n = 0; n < 31; n++)
  			if (audit_tree_match(p->c[n], tree))
  				return 1;
  	}
  	/* partial */
  	if (p) {
  		for (n = ctx->tree_count; n < 31; n++)
  			if (audit_tree_match(p->c[n], tree))
  				return 1;
  	}
  #endif
  	return 0;
  }

  static int audit_compare_uid(kuid_t uid,
  			     struct audit_names *name,
  			     struct audit_field *f,
  			     struct audit_context *ctx)

  {
  	struct audit_names *n;

  	int rc;

  	if (name) {

  		rc = audit_uid_comparator(uid, f->op, name->uid);

  		if (rc)
  			return rc;
  	}

  	if (ctx) {
  		list_for_each_entry(n, &ctx->names_list, list) {

  			rc = audit_uid_comparator(uid, f->op, n->uid);
  			if (rc)
  				return rc;
  		}
  	}
  	return 0;
  }

  static int audit_compare_gid(kgid_t gid,
  			     struct audit_names *name,
  			     struct audit_field *f,
  			     struct audit_context *ctx)
  {
  	struct audit_names *n;
  	int rc;
   
  	if (name) {
  		rc = audit_gid_comparator(gid, f->op, name->gid);
  		if (rc)
  			return rc;
  	}
   
  	if (ctx) {
  		list_for_each_entry(n, &ctx->names_list, list) {
  			rc = audit_gid_comparator(gid, f->op, n->gid);

  			if (rc)
  				return rc;
  		}
  	}
  	return 0;
  }

  static int audit_field_compare(struct task_struct *tsk,
  			       const struct cred *cred,
  			       struct audit_field *f,
  			       struct audit_context *ctx,
  			       struct audit_names *name)
  {

  	switch (f->val) {

  	/* process to file object comparisons */

  	case AUDIT_COMPARE_UID_TO_OBJ_UID:

  		return audit_compare_uid(cred->uid, name, f, ctx);

  	case AUDIT_COMPARE_GID_TO_OBJ_GID:

  		return audit_compare_gid(cred->gid, name, f, ctx);

  	case AUDIT_COMPARE_EUID_TO_OBJ_UID:

  		return audit_compare_uid(cred->euid, name, f, ctx);

  	case AUDIT_COMPARE_EGID_TO_OBJ_GID:

  		return audit_compare_gid(cred->egid, name, f, ctx);

  	case AUDIT_COMPARE_AUID_TO_OBJ_UID:

  		return audit_compare_uid(tsk->loginuid, name, f, ctx);

  	case AUDIT_COMPARE_SUID_TO_OBJ_UID:

  		return audit_compare_uid(cred->suid, name, f, ctx);

  	case AUDIT_COMPARE_SGID_TO_OBJ_GID:

  		return audit_compare_gid(cred->sgid, name, f, ctx);

  	case AUDIT_COMPARE_FSUID_TO_OBJ_UID:

  		return audit_compare_uid(cred->fsuid, name, f, ctx);

  	case AUDIT_COMPARE_FSGID_TO_OBJ_GID:

  		return audit_compare_gid(cred->fsgid, name, f, ctx);

  	/* uid comparisons */
  	case AUDIT_COMPARE_UID_TO_AUID:

  		return audit_uid_comparator(cred->uid, f->op, tsk->loginuid);

  	case AUDIT_COMPARE_UID_TO_EUID:

  		return audit_uid_comparator(cred->uid, f->op, cred->euid);

  	case AUDIT_COMPARE_UID_TO_SUID:

  		return audit_uid_comparator(cred->uid, f->op, cred->suid);

  	case AUDIT_COMPARE_UID_TO_FSUID:

  		return audit_uid_comparator(cred->uid, f->op, cred->fsuid);

  	/* auid comparisons */
  	case AUDIT_COMPARE_AUID_TO_EUID:

  		return audit_uid_comparator(tsk->loginuid, f->op, cred->euid);

  	case AUDIT_COMPARE_AUID_TO_SUID:

  		return audit_uid_comparator(tsk->loginuid, f->op, cred->suid);

  	case AUDIT_COMPARE_AUID_TO_FSUID:

  		return audit_uid_comparator(tsk->loginuid, f->op, cred->fsuid);

  	/* euid comparisons */
  	case AUDIT_COMPARE_EUID_TO_SUID:

  		return audit_uid_comparator(cred->euid, f->op, cred->suid);

  	case AUDIT_COMPARE_EUID_TO_FSUID:

  		return audit_uid_comparator(cred->euid, f->op, cred->fsuid);

  	/* suid comparisons */
  	case AUDIT_COMPARE_SUID_TO_FSUID:

  		return audit_uid_comparator(cred->suid, f->op, cred->fsuid);

  	/* gid comparisons */
  	case AUDIT_COMPARE_GID_TO_EGID:

  		return audit_gid_comparator(cred->gid, f->op, cred->egid);

  	case AUDIT_COMPARE_GID_TO_SGID:

  		return audit_gid_comparator(cred->gid, f->op, cred->sgid);

  	case AUDIT_COMPARE_GID_TO_FSGID:

  		return audit_gid_comparator(cred->gid, f->op, cred->fsgid);

  	/* egid comparisons */
  	case AUDIT_COMPARE_EGID_TO_SGID:

  		return audit_gid_comparator(cred->egid, f->op, cred->sgid);

  	case AUDIT_COMPARE_EGID_TO_FSGID:

  		return audit_gid_comparator(cred->egid, f->op, cred->fsgid);

  	/* sgid comparison */
  	case AUDIT_COMPARE_SGID_TO_FSGID:

  		return audit_gid_comparator(cred->sgid, f->op, cred->fsgid);

  	default:
  		WARN(1, "Missing AUDIT_COMPARE define.  Report as a bug
  ");
  		return 0;
  	}
  	return 0;
  }

  /* Determine if any context name data matches a rule's watch data */

  /* Compare a task_struct with an audit_rule.  Return 1 on match, 0

   * otherwise.
   *
   * If task_creation is true, this is an explicit indication that we are
   * filtering a task rule at task creation time.  This and tsk == current are
   * the only situations where tsk->cred may be accessed without an rcu read lock.
   */

  static int audit_filter_rules(struct task_struct *tsk,

  			      struct audit_krule *rule,

  			      struct audit_context *ctx,

  			      struct audit_names *name,

  			      enum audit_state *state,
  			      bool task_creation)

  {

  	const struct cred *cred;

  	int i, need_sid = 1;

  	u32 sid;

  	cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);

  	for (i = 0; i < rule->field_count; i++) {

  		struct audit_field *f = &rule->fields[i];

  		struct audit_names *n;

  		int result = 0;

  		switch (f->type) {

  		case AUDIT_PID:

  			result = audit_comparator(tsk->pid, f->op, f->val);

  			break;

  		case AUDIT_PPID:

  			if (ctx) {
  				if (!ctx->ppid)
  					ctx->ppid = sys_getppid();

  				result = audit_comparator(ctx->ppid, f->op, f->val);

  			}

  			break;

  		case AUDIT_UID:

  			result = audit_uid_comparator(cred->uid, f->op, f->uid);

  			break;
  		case AUDIT_EUID:

  			result = audit_uid_comparator(cred->euid, f->op, f->uid);

  			break;
  		case AUDIT_SUID:

  			result = audit_uid_comparator(cred->suid, f->op, f->uid);

  			break;
  		case AUDIT_FSUID:

  			result = audit_uid_comparator(cred->fsuid, f->op, f->uid);

  			break;
  		case AUDIT_GID:

  			result = audit_gid_comparator(cred->gid, f->op, f->gid);

  			if (f->op == Audit_equal) {
  				if (!result)
  					result = in_group_p(f->gid);
  			} else if (f->op == Audit_not_equal) {
  				if (result)
  					result = !in_group_p(f->gid);
  			}

  			break;
  		case AUDIT_EGID:

  			result = audit_gid_comparator(cred->egid, f->op, f->gid);

  			if (f->op == Audit_equal) {
  				if (!result)
  					result = in_egroup_p(f->gid);
  			} else if (f->op == Audit_not_equal) {
  				if (result)
  					result = !in_egroup_p(f->gid);
  			}

  			break;
  		case AUDIT_SGID:

  			result = audit_gid_comparator(cred->sgid, f->op, f->gid);

  			break;
  		case AUDIT_FSGID:

  			result = audit_gid_comparator(cred->fsgid, f->op, f->gid);

  			break;
  		case AUDIT_PERS:

  			result = audit_comparator(tsk->personality, f->op, f->val);

  			break;

  		case AUDIT_ARCH:

  			if (ctx)

  				result = audit_comparator(ctx->arch, f->op, f->val);

  			break;

  
  		case AUDIT_EXIT:
  			if (ctx && ctx->return_valid)

  				result = audit_comparator(ctx->return_code, f->op, f->val);

  			break;
  		case AUDIT_SUCCESS:

  			if (ctx && ctx->return_valid) {

  				if (f->val)
  					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);

  				else

  					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE);

  			}

  			break;
  		case AUDIT_DEVMAJOR:

  			if (name) {
  				if (audit_comparator(MAJOR(name->dev), f->op, f->val) ||
  				    audit_comparator(MAJOR(name->rdev), f->op, f->val))
  					++result;
  			} else if (ctx) {

  				list_for_each_entry(n, &ctx->names_list, list) {

  					if (audit_comparator(MAJOR(n->dev), f->op, f->val) ||
  					    audit_comparator(MAJOR(n->rdev), f->op, f->val)) {

  						++result;
  						break;
  					}
  				}
  			}
  			break;
  		case AUDIT_DEVMINOR:

  			if (name) {
  				if (audit_comparator(MINOR(name->dev), f->op, f->val) ||
  				    audit_comparator(MINOR(name->rdev), f->op, f->val))
  					++result;
  			} else if (ctx) {

  				list_for_each_entry(n, &ctx->names_list, list) {

  					if (audit_comparator(MINOR(n->dev), f->op, f->val) ||
  					    audit_comparator(MINOR(n->rdev), f->op, f->val)) {

  						++result;
  						break;
  					}
  				}
  			}
  			break;
  		case AUDIT_INODE:

  			if (name)

  				result = (name->ino == f->val);

  			else if (ctx) {

  				list_for_each_entry(n, &ctx->names_list, list) {
  					if (audit_comparator(n->ino, f->op, f->val)) {

  						++result;
  						break;
  					}
  				}
  			}
  			break;

  		case AUDIT_OBJ_UID:
  			if (name) {

  				result = audit_uid_comparator(name->uid, f->op, f->uid);

  			} else if (ctx) {
  				list_for_each_entry(n, &ctx->names_list, list) {

  					if (audit_uid_comparator(n->uid, f->op, f->uid)) {

  						++result;
  						break;
  					}
  				}
  			}
  			break;

  		case AUDIT_OBJ_GID:
  			if (name) {

  				result = audit_gid_comparator(name->gid, f->op, f->gid);

  			} else if (ctx) {
  				list_for_each_entry(n, &ctx->names_list, list) {

  					if (audit_gid_comparator(n->gid, f->op, f->gid)) {

  						++result;
  						break;
  					}
  				}
  			}
  			break;

  		case AUDIT_WATCH:

  			if (name)
  				result = audit_watch_compare(rule->watch, name->ino, name->dev);

  			break;

  		case AUDIT_DIR:
  			if (ctx)
  				result = match_tree_refs(ctx, rule->tree);
  			break;

  		case AUDIT_LOGINUID:
  			result = 0;
  			if (ctx)

  				result = audit_uid_comparator(tsk->loginuid, f->op, f->uid);

  			break;

  		case AUDIT_LOGINUID_SET:
  			result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
  			break;

  		case AUDIT_SUBJ_USER:
  		case AUDIT_SUBJ_ROLE:
  		case AUDIT_SUBJ_TYPE:
  		case AUDIT_SUBJ_SEN:
  		case AUDIT_SUBJ_CLR:

  			/* NOTE: this may return negative values indicating
  			   a temporary error.  We simply treat this as a
  			   match for now to avoid losing information that
  			   may be wanted.   An error message will also be
  			   logged upon error */

  			if (f->lsm_rule) {

  				if (need_sid) {

  					security_task_getsecid(tsk, &sid);

  					need_sid = 0;
  				}

  				result = security_audit_rule_match(sid, f->type,

  				                                  f->op,

  				                                  f->lsm_rule,

  				                                  ctx);

  			}

  			break;

  		case AUDIT_OBJ_USER:
  		case AUDIT_OBJ_ROLE:
  		case AUDIT_OBJ_TYPE:
  		case AUDIT_OBJ_LEV_LOW:
  		case AUDIT_OBJ_LEV_HIGH:
  			/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
  			   also applies here */

  			if (f->lsm_rule) {

  				/* Find files that match */
  				if (name) {

  					result = security_audit_rule_match(

  					           name->osid, f->type, f->op,

  					           f->lsm_rule, ctx);

  				} else if (ctx) {

  					list_for_each_entry(n, &ctx->names_list, list) {
  						if (security_audit_rule_match(n->osid, f->type,
  									      f->op, f->lsm_rule,
  									      ctx)) {

  							++result;
  							break;
  						}
  					}
  				}
  				/* Find ipc objects that match */

  				if (!ctx || ctx->type != AUDIT_IPC)
  					break;
  				if (security_audit_rule_match(ctx->ipc.osid,
  							      f->type, f->op,
  							      f->lsm_rule, ctx))
  					++result;

  			}
  			break;

  		case AUDIT_ARG0:
  		case AUDIT_ARG1:
  		case AUDIT_ARG2:
  		case AUDIT_ARG3:
  			if (ctx)

  				result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val);

  			break;

  		case AUDIT_FILTERKEY:
  			/* ignore this field for filtering */
  			result = 1;
  			break;

  		case AUDIT_PERM:
  			result = audit_match_perm(ctx, f->val);
  			break;

  		case AUDIT_FILETYPE:
  			result = audit_match_filetype(ctx, f->val);
  			break;

  		case AUDIT_FIELD_COMPARE:
  			result = audit_field_compare(tsk, cred, f, ctx, name);
  			break;

  		}

  		if (!result)

  			return 0;
  	}

  
  	if (ctx) {
  		if (rule->prio <= ctx->prio)
  			return 0;
  		if (rule->filterkey) {
  			kfree(ctx->filterkey);
  			ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
  		}
  		ctx->prio = rule->prio;
  	}

  	switch (rule->action) {
  	case AUDIT_NEVER:    *state = AUDIT_DISABLED;	    break;

  	case AUDIT_ALWAYS:   *state = AUDIT_RECORD_CONTEXT; break;
  	}
  	return 1;
  }
  
  /* At process creation time, we can determine if system-call auditing is
   * completely disabled for this task.  Since we only have the task
   * structure at this point, we can only check uid and gid.
   */

  static enum audit_state audit_filter_task(struct task_struct *tsk, char **key)

  {
  	struct audit_entry *e;
  	enum audit_state   state;
  
  	rcu_read_lock();

  	list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {

  		if (audit_filter_rules(tsk, &e->rule, NULL, NULL,
  				       &state, true)) {

  			if (state == AUDIT_RECORD_CONTEXT)
  				*key = kstrdup(e->rule.filterkey, GFP_ATOMIC);

  			rcu_read_unlock();
  			return state;
  		}
  	}
  	rcu_read_unlock();
  	return AUDIT_BUILD_CONTEXT;
  }
  
  /* At syscall entry and exit time, this filter is called if the
   * audit_state is not low enough that auditing cannot take place, but is

   * also not high enough that we already know we have to write an audit

   * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).

   */
  static enum audit_state audit_filter_syscall(struct task_struct *tsk,
  					     struct audit_context *ctx,
  					     struct list_head *list)
  {
  	struct audit_entry *e;

  	enum audit_state state;

  	if (audit_pid && tsk->tgid == audit_pid)

  		return AUDIT_DISABLED;

  	rcu_read_lock();

  	if (!list_empty(list)) {

  		int word = AUDIT_WORD(ctx->major);
  		int bit  = AUDIT_BIT(ctx->major);
  
  		list_for_each_entry_rcu(e, list, list) {

  			if ((e->rule.mask[word] & bit) == bit &&
  			    audit_filter_rules(tsk, &e->rule, ctx, NULL,

  					       &state, false)) {

  				rcu_read_unlock();

  				ctx->current_state = state;

  				return state;
  			}
  		}
  	}
  	rcu_read_unlock();
  	return AUDIT_BUILD_CONTEXT;
  }

  /*
   * Given an audit_name check the inode hash table to see if they match.
   * Called holding the rcu read lock to protect the use of audit_inode_hash
   */
  static int audit_filter_inode_name(struct task_struct *tsk,
  				   struct audit_names *n,
  				   struct audit_context *ctx) {
  	int word, bit;
  	int h = audit_hash_ino((u32)n->ino);
  	struct list_head *list = &audit_inode_hash[h];
  	struct audit_entry *e;
  	enum audit_state state;
  
  	word = AUDIT_WORD(ctx->major);
  	bit  = AUDIT_BIT(ctx->major);
  
  	if (list_empty(list))
  		return 0;
  
  	list_for_each_entry_rcu(e, list, list) {
  		if ((e->rule.mask[word] & bit) == bit &&
  		    audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) {
  			ctx->current_state = state;
  			return 1;
  		}
  	}
  
  	return 0;
  }
  
  /* At syscall exit time, this filter is called if any audit_names have been

   * collected during syscall processing.  We only check rules in sublists at hash

   * buckets applicable to the inode numbers in audit_names.

   * Regarding audit_state, same rules apply as for audit_filter_syscall().
   */

  void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)

  {

  	struct audit_names *n;

  
  	if (audit_pid && tsk->tgid == audit_pid)

  		return;

  
  	rcu_read_lock();

  	list_for_each_entry(n, &ctx->names_list, list) {
  		if (audit_filter_inode_name(tsk, n, ctx))
  			break;

  	}
  	rcu_read_unlock();

  }

  static inline struct audit_context *audit_get_context(struct task_struct *tsk,
  						      int return_valid,

  						      long return_code)

  {
  	struct audit_context *context = tsk->audit_context;

  	if (!context)

  		return NULL;
  	context->return_valid = return_valid;

  
  	/*
  	 * we need to fix up the return code in the audit logs if the actual
  	 * return codes are later going to be fixed up by the arch specific
  	 * signal handlers
  	 *
  	 * This is actually a test for:
  	 * (rc == ERESTARTSYS ) || (rc == ERESTARTNOINTR) ||
  	 * (rc == ERESTARTNOHAND) || (rc == ERESTART_RESTARTBLOCK)
  	 *
  	 * but is faster than a bunch of ||
  	 */
  	if (unlikely(return_code <= -ERESTARTSYS) &&
  	    (return_code >= -ERESTART_RESTARTBLOCK) &&
  	    (return_code != -ENOIOCTLCMD))
  		context->return_code = -EINTR;
  	else
  		context->return_code  = return_code;

  	if (context->in_syscall && !context->dummy) {
  		audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
  		audit_filter_inodes(tsk, context);

  	}

  	tsk->audit_context = NULL;
  	return context;
  }
  
  static inline void audit_free_names(struct audit_context *context)
  {

  	struct audit_names *n, *next;

  
  #if AUDIT_DEBUG == 2

  	if (context->put_count + context->ino_count != context->name_count) {

  		int i = 0;

  		printk(KERN_ERR "%s:%d(:%d): major=%d in_syscall=%d"

  		       " name_count=%d put_count=%d"
  		       " ino_count=%d [NOT freeing]
  ",

  		       __FILE__, __LINE__,

  		       context->serial, context->major, context->in_syscall,
  		       context->name_count, context->put_count,
  		       context->ino_count);

  		list_for_each_entry(n, &context->names_list, list) {

  			printk(KERN_ERR "names[%d] = %p = %s
  ", i++,

  			       n->name, n->name->name ?: "(null)");

  		}

  		dump_stack();
  		return;
  	}
  #endif
  #if AUDIT_DEBUG
  	context->put_count  = 0;
  	context->ino_count  = 0;
  #endif

  	list_for_each_entry_safe(n, next, &context->names_list, list) {
  		list_del(&n->list);
  		if (n->name && n->name_put)

  			final_putname(n->name);

  		if (n->should_free)
  			kfree(n);

  	}

  	context->name_count = 0;

  	path_put(&context->pwd);
  	context->pwd.dentry = NULL;
  	context->pwd.mnt = NULL;

  }
  
  static inline void audit_free_aux(struct audit_context *context)
  {
  	struct audit_aux_data *aux;
  
  	while ((aux = context->aux)) {
  		context->aux = aux->next;
  		kfree(aux);
  	}

  	while ((aux = context->aux_pids)) {
  		context->aux_pids = aux->next;
  		kfree(aux);
  	}

  }

  static inline struct audit_context *audit_alloc_context(enum audit_state state)
  {
  	struct audit_context *context;

  	context = kzalloc(sizeof(*context), GFP_KERNEL);
  	if (!context)

  		return NULL;

  	context->state = state;
  	context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;

  	INIT_LIST_HEAD(&context->killed_trees);

  	INIT_LIST_HEAD(&context->names_list);

  	return context;
  }

  /**
   * audit_alloc - allocate an audit context block for a task
   * @tsk: task
   *
   * Filter on the task information and allocate a per-task audit context

   * if necessary.  Doing so turns on system call auditing for the
   * specified task.  This is called from copy_process, so no lock is

   * needed.
   */

  int audit_alloc(struct task_struct *tsk)
  {
  	struct audit_context *context;
  	enum audit_state     state;

  	char *key = NULL;

  	if (likely(!audit_ever_enabled))

  		return 0; /* Return if not auditing. */

  	state = audit_filter_task(tsk, &key);

  	if (state == AUDIT_DISABLED)

  		return 0;
  
  	if (!(context = audit_alloc_context(state))) {

  		kfree(key);

  		audit_log_lost("out of memory in audit_alloc");
  		return -ENOMEM;
  	}

  	context->filterkey = key;

  	tsk->audit_context  = context;
  	set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
  	return 0;
  }
  
  static inline void audit_free_context(struct audit_context *context)
  {

  	audit_free_names(context);
  	unroll_tree_refs(context, NULL, 0);
  	free_tree_refs(context);
  	audit_free_aux(context);
  	kfree(context->filterkey);
  	kfree(context->sockaddr);
  	kfree(context);

  }

  static int audit_log_pid_context(struct audit_context *context, pid_t pid,

  				 kuid_t auid, kuid_t uid, unsigned int sessionid,

  				 u32 sid, char *comm)

  {
  	struct audit_buffer *ab;

  	char *ctx = NULL;

  	u32 len;
  	int rc = 0;
  
  	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
  	if (!ab)

  		return rc;

  	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
  			 from_kuid(&init_user_ns, auid),

  			 from_kuid(&init_user_ns, uid), sessionid);

  	if (sid) {
  		if (security_secid_to_secctx(sid, &ctx, &len)) {
  			audit_log_format(ab, " obj=(none)");
  			rc = 1;
  		} else {
  			audit_log_format(ab, " obj=%s", ctx);
  			security_release_secctx(ctx, len);
  		}

  	}

  	audit_log_format(ab, " ocomm=");
  	audit_log_untrustedstring(ab, comm);

  	audit_log_end(ab);

  
  	return rc;
  }

  /*
   * to_send and len_sent accounting are very loose estimates.  We aren't
   * really worried about a hard cap to MAX_EXECVE_AUDIT_LEN so much as being

   * within about 500 bytes (next page boundary)

   *
   * why snprintf?  an int is up to 12 digits long.  if we just assumed when
   * logging that a[%d]= was going to be 16 characters long we would be wasting
   * space in every audit message.  In one 7500 byte message we can log up to
   * about 1000 min size arguments.  That comes down to about 50% waste of space
   * if we didn't do the snprintf to find out how long arg_num_len was.
   */
  static int audit_log_single_execve_arg(struct audit_context *context,
  					struct audit_buffer **ab,
  					int arg_num,
  					size_t *len_sent,
  					const char __user *p,
  					char *buf)

  {

  	char arg_num_len_buf[12];
  	const char __user *tmp_p = p;

  	/* how many digits are in arg_num? 5 is the length of ' a=""' */
  	size_t arg_num_len = snprintf(arg_num_len_buf, 12, "%d", arg_num) + 5;

  	size_t len, len_left, to_send;
  	size_t max_execve_audit_len = MAX_EXECVE_AUDIT_LEN;
  	unsigned int i, has_cntl = 0, too_long = 0;
  	int ret;
  
  	/* strnlen_user includes the null we don't want to send */
  	len_left = len = strnlen_user(p, MAX_ARG_STRLEN) - 1;

  	/*
  	 * We just created this mm, if we can't find the strings
  	 * we just copied into it something is _very_ wrong. Similar
  	 * for strings that are too long, we should not have created
  	 * any.
  	 */

  	if (unlikely((len == -1) || len > MAX_ARG_STRLEN - 1)) {

  		WARN_ON(1);
  		send_sig(SIGKILL, current, 0);

  		return -1;

  	}

  	/* walk the whole argument looking for non-ascii chars */
  	do {
  		if (len_left > MAX_EXECVE_AUDIT_LEN)
  			to_send = MAX_EXECVE_AUDIT_LEN;
  		else
  			to_send = len_left;
  		ret = copy_from_user(buf, tmp_p, to_send);

  		/*

  		 * There is no reason for this copy to be short. We just
  		 * copied them here, and the mm hasn't been exposed to user-
  		 * space yet.

  		 */

  		if (ret) {

  			WARN_ON(1);
  			send_sig(SIGKILL, current, 0);

  			return -1;

  		}

  		buf[to_send] = '\0';
  		has_cntl = audit_string_contains_control(buf, to_send);
  		if (has_cntl) {
  			/*
  			 * hex messages get logged as 2 bytes, so we can only
  			 * send half as much in each message
  			 */
  			max_execve_audit_len = MAX_EXECVE_AUDIT_LEN / 2;

  			break;
  		}

  		len_left -= to_send;
  		tmp_p += to_send;
  	} while (len_left > 0);
  
  	len_left = len;
  
  	if (len > max_execve_audit_len)
  		too_long = 1;
  
  	/* rewalk the argument actually logging the message */
  	for (i = 0; len_left > 0; i++) {
  		int room_left;
  
  		if (len_left > max_execve_audit_len)
  			to_send = max_execve_audit_len;
  		else
  			to_send = len_left;
  
  		/* do we have space left to send this argument in this ab? */
  		room_left = MAX_EXECVE_AUDIT_LEN - arg_num_len - *len_sent;
  		if (has_cntl)
  			room_left -= (to_send * 2);
  		else
  			room_left -= to_send;
  		if (room_left < 0) {
  			*len_sent = 0;
  			audit_log_end(*ab);
  			*ab = audit_log_start(context, GFP_KERNEL, AUDIT_EXECVE);
  			if (!*ab)
  				return 0;
  		}

  		/*

  		 * first record needs to say how long the original string was
  		 * so we can be sure nothing was lost.
  		 */
  		if ((i == 0) && (too_long))

  			audit_log_format(*ab, " a%d_len=%zu", arg_num,

  					 has_cntl ? 2*len : len);
  
  		/*
  		 * normally arguments are small enough to fit and we already
  		 * filled buf above when we checked for control characters
  		 * so don't bother with another copy_from_user

  		 */

  		if (len >= max_execve_audit_len)
  			ret = copy_from_user(buf, p, to_send);
  		else
  			ret = 0;

  		if (ret) {

  			WARN_ON(1);
  			send_sig(SIGKILL, current, 0);

  			return -1;

  		}

  		buf[to_send] = '\0';
  
  		/* actually log it */

  		audit_log_format(*ab, " a%d", arg_num);

  		if (too_long)
  			audit_log_format(*ab, "[%d]", i);
  		audit_log_format(*ab, "=");
  		if (has_cntl)

  			audit_log_n_hex(*ab, buf, to_send);

  		else

  			audit_log_string(*ab, buf);

  
  		p += to_send;
  		len_left -= to_send;
  		*len_sent += arg_num_len;
  		if (has_cntl)
  			*len_sent += to_send * 2;
  		else
  			*len_sent += to_send;
  	}
  	/* include the null we didn't log */
  	return len + 1;
  }
  
  static void audit_log_execve_info(struct audit_context *context,
  				  struct audit_buffer **ab,
  				  struct audit_aux_data_execve *axi)
  {

  	int i, len;
  	size_t len_sent = 0;

  	const char __user *p;
  	char *buf;

  	if (axi->mm != current->mm)
  		return; /* execve failed, no additional info */
  
  	p = (const char __user *)axi->mm->arg_start;

  	audit_log_format(*ab, "argc=%d", axi->argc);

  
  	/*
  	 * we need some kernel buffer to hold the userspace args.  Just
  	 * allocate one big one rather than allocating one of the right size
  	 * for every single argument inside audit_log_single_execve_arg()
  	 * should be <8k allocation so should be pretty safe.
  	 */
  	buf = kmalloc(MAX_EXECVE_AUDIT_LEN + 1, GFP_KERNEL);
  	if (!buf) {
  		audit_panic("out of memory for argv string
  ");
  		return;

  	}

  
  	for (i = 0; i < axi->argc; i++) {
  		len = audit_log_single_execve_arg(context, ab, i,
  						  &len_sent, p, buf);
  		if (len <= 0)
  			break;
  		p += len;
  	}
  	kfree(buf);

  }

  static void show_special(struct audit_context *context, int *call_panic)

  {
  	struct audit_buffer *ab;
  	int i;
  
  	ab = audit_log_start(context, GFP_KERNEL, context->type);
  	if (!ab)
  		return;
  
  	switch (context->type) {
  	case AUDIT_SOCKETCALL: {
  		int nargs = context->socketcall.nargs;
  		audit_log_format(ab, "nargs=%d", nargs);
  		for (i = 0; i < nargs; i++)
  			audit_log_format(ab, " a%d=%lx", i,
  				context->socketcall.args[i]);
  		break; }

  	case AUDIT_IPC: {
  		u32 osid = context->ipc.osid;

  		audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",

  				 from_kuid(&init_user_ns, context->ipc.uid),
  				 from_kgid(&init_user_ns, context->ipc.gid),
  				 context->ipc.mode);

  		if (osid) {
  			char *ctx = NULL;
  			u32 len;
  			if (security_secid_to_secctx(osid, &ctx, &len)) {
  				audit_log_format(ab, " osid=%u", osid);
  				*call_panic = 1;
  			} else {
  				audit_log_format(ab, " obj=%s", ctx);
  				security_release_secctx(ctx, len);
  			}
  		}

  		if (context->ipc.has_perm) {
  			audit_log_end(ab);
  			ab = audit_log_start(context, GFP_KERNEL,
  					     AUDIT_IPC_SET_PERM);

  			if (unlikely(!ab))
  				return;

  			audit_log_format(ab,

  				"qbytes=%lx ouid=%u ogid=%u mode=%#ho",

  				context->ipc.qbytes,
  				context->ipc.perm_uid,
  				context->ipc.perm_gid,
  				context->ipc.perm_mode);

  		}

  		break; }

  	case AUDIT_MQ_OPEN: {
  		audit_log_format(ab,

  			"oflag=0x%x mode=%#ho mq_flags=0x%lx mq_maxmsg=%ld "

  			"mq_msgsize=%ld mq_curmsgs=%ld",
  			context->mq_open.oflag, context->mq_open.mode,
  			context->mq_open.attr.mq_flags,
  			context->mq_open.attr.mq_maxmsg,
  			context->mq_open.attr.mq_msgsize,
  			context->mq_open.attr.mq_curmsgs);
  		break; }

  	case AUDIT_MQ_SENDRECV: {
  		audit_log_format(ab,
  			"mqdes=%d msg_len=%zd msg_prio=%u "
  			"abs_timeout_sec=%ld abs_timeout_nsec=%ld",
  			context->mq_sendrecv.mqdes,
  			context->mq_sendrecv.msg_len,
  			context->mq_sendrecv.msg_prio,
  			context->mq_sendrecv.abs_timeout.tv_sec,
  			context->mq_sendrecv.abs_timeout.tv_nsec);
  		break; }

  	case AUDIT_MQ_NOTIFY: {
  		audit_log_format(ab, "mqdes=%d sigev_signo=%d",
  				context->mq_notify.mqdes,
  				context->mq_notify.sigev_signo);
  		break; }

  	case AUDIT_MQ_GETSETATTR: {
  		struct mq_attr *attr = &context->mq_getsetattr.mqstat;
  		audit_log_format(ab,
  			"mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
  			"mq_curmsgs=%ld ",
  			context->mq_getsetattr.mqdes,
  			attr->mq_flags, attr->mq_maxmsg,
  			attr->mq_msgsize, attr->mq_curmsgs);
  		break; }

  	case AUDIT_CAPSET: {
  		audit_log_format(ab, "pid=%d", context->capset.pid);
  		audit_log_cap(ab, "cap_pi", &context->capset.cap.inheritable);
  		audit_log_cap(ab, "cap_pp", &context->capset.cap.permitted);
  		audit_log_cap(ab, "cap_pe", &context->capset.cap.effective);
  		break; }

  	case AUDIT_MMAP: {
  		audit_log_format(ab, "fd=%d flags=0x%x", context->mmap.fd,
  				 context->mmap.flags);
  		break; }

  	}
  	audit_log_end(ab);
  }

  static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)

  {

  	int i, call_panic = 0;

  	struct audit_buffer *ab;

  	struct audit_aux_data *aux;

  	struct audit_names *n;

  	/* tsk == current */

  	context->personality = tsk->personality;

  
  	ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);

  	if (!ab)
  		return;		/* audit_panic has been called */

  	audit_log_format(ab, "arch=%x syscall=%d",
  			 context->arch, context->major);

  	if (context->personality != PER_LINUX)
  		audit_log_format(ab, " per=%lx", context->personality);
  	if (context->return_valid)

  		audit_log_format(ab, " success=%s exit=%ld",

  				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
  				 context->return_code);

  	audit_log_format(ab,

  			 " a0=%lx a1=%lx a2=%lx a3=%lx items=%d",
  			 context->argv[0],
  			 context->argv[1],
  			 context->argv[2],
  			 context->argv[3],
  			 context->name_count);

  	audit_log_task_info(ab, tsk);

  	audit_log_key(ab, context->filterkey);

  	audit_log_end(ab);

  	for (aux = context->aux; aux; aux = aux->next) {

  		ab = audit_log_start(context, GFP_KERNEL, aux->type);

  		if (!ab)
  			continue; /* audit_panic has been called */

  		switch (aux->type) {

  		case AUDIT_EXECVE: {
  			struct audit_aux_data_execve *axi = (void *)aux;

  			audit_log_execve_info(context, &ab, axi);

  			break; }

  		case AUDIT_BPRM_FCAPS: {
  			struct audit_aux_data_bprm_fcaps *axs = (void *)aux;
  			audit_log_format(ab, "fver=%x", axs->fcap_ver);
  			audit_log_cap(ab, "fp", &axs->fcap.permitted);
  			audit_log_cap(ab, "fi", &axs->fcap.inheritable);
  			audit_log_format(ab, " fe=%d", axs->fcap.fE);
  			audit_log_cap(ab, "old_pp", &axs->old_pcap.permitted);
  			audit_log_cap(ab, "old_pi", &axs->old_pcap.inheritable);
  			audit_log_cap(ab, "old_pe", &axs->old_pcap.effective);
  			audit_log_cap(ab, "new_pp", &axs->new_pcap.permitted);
  			audit_log_cap(ab, "new_pi", &axs->new_pcap.inheritable);
  			audit_log_cap(ab, "new_pe", &axs->new_pcap.effective);
  			break; }

  		}
  		audit_log_end(ab);

  	}

  	if (context->type)

  		show_special(context, &call_panic);

  	if (context->fds[0] >= 0) {
  		ab = audit_log_start(context, GFP_KERNEL, AUDIT_FD_PAIR);
  		if (ab) {
  			audit_log_format(ab, "fd0=%d fd1=%d",
  					context->fds[0], context->fds[1]);
  			audit_log_end(ab);
  		}
  	}

  	if (context->sockaddr_len) {
  		ab = audit_log_start(context, GFP_KERNEL, AUDIT_SOCKADDR);
  		if (ab) {
  			audit_log_format(ab, "saddr=");
  			audit_log_n_hex(ab, (void *)context->sockaddr,
  					context->sockaddr_len);
  			audit_log_end(ab);
  		}
  	}

  	for (aux = context->aux_pids; aux; aux = aux->next) {
  		struct audit_aux_data_pids *axs = (void *)aux;

  
  		for (i = 0; i < axs->pid_count; i++)
  			if (audit_log_pid_context(context, axs->target_pid[i],

  						  axs->target_auid[i],
  						  axs->target_uid[i],

  						  axs->target_sessionid[i],

  						  axs->target_sid[i],
  						  axs->target_comm[i]))

  				call_panic = 1;

  	}

  	if (context->target_pid &&
  	    audit_log_pid_context(context, context->target_pid,

  				  context->target_auid, context->target_uid,

  				  context->target_sessionid,

  				  context->target_sid, context->target_comm))

  			call_panic = 1;

  	if (context->pwd.dentry && context->pwd.mnt) {

  		ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);

  		if (ab) {

  			audit_log_d_path(ab, " cwd=", &context->pwd);

  			audit_log_end(ab);
  		}
  	}

  	i = 0;
  	list_for_each_entry(n, &context->names_list, list)

  		audit_log_name(context, n, NULL, i++, &call_panic);

  
  	/* Send end of event record to help user space know we are finished */
  	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
  	if (ab)
  		audit_log_end(ab);

  	if (call_panic)
  		audit_panic("error converting sid to string");

  }

  /**
   * audit_free - free a per-task audit context
   * @tsk: task whose audit context block to free
   *

   * Called from copy_process and do_exit

   */

  void __audit_free(struct task_struct *tsk)

  {
  	struct audit_context *context;

  	context = audit_get_context(tsk, 0, 0);

  	if (!context)

  		return;
  
  	/* Check for system calls that do not go through the exit

  	 * function (e.g., exit_group), then free context block.
  	 * We use GFP_ATOMIC here because we might be doing this

  	 * in the context of the idle thread */

  	/* that can happen only if we are called from do_exit() */

  	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)

  		audit_log_exit(context, tsk);

  	if (!list_empty(&context->killed_trees))
  		audit_kill_trees(&context->killed_trees);

  
  	audit_free_context(context);
  }

  /**
   * audit_syscall_entry - fill in an audit record at syscall entry

   * @arch: architecture type
   * @major: major syscall type (function)
   * @a1: additional syscall register 1
   * @a2: additional syscall register 2
   * @a3: additional syscall register 3
   * @a4: additional syscall register 4
   *
   * Fill in audit context at syscall entry.  This only happens if the

   * audit context was created when the task was created and the state or
   * filters demand the audit context be built.  If the state from the
   * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
   * then the record will be written at syscall exit time (otherwise, it
   * will only be written if another part of the kernel requests that it

   * be written).
   */

  void __audit_syscall_entry(int arch, int major,

  			 unsigned long a1, unsigned long a2,
  			 unsigned long a3, unsigned long a4)
  {

  	struct task_struct *tsk = current;

  	struct audit_context *context = tsk->audit_context;
  	enum audit_state     state;

  	if (!context)

  		return;

  	BUG_ON(context->in_syscall || context->name_count);
  
  	if (!audit_enabled)
  		return;

  	context->arch	    = arch;

  	context->major      = major;
  	context->argv[0]    = a1;
  	context->argv[1]    = a2;
  	context->argv[2]    = a3;
  	context->argv[3]    = a4;
  
  	state = context->state;

  	context->dummy = !audit_n_rules;

  	if (!context->dummy && state == AUDIT_BUILD_CONTEXT) {
  		context->prio = 0;

  		state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);

  	}

  	if (state == AUDIT_DISABLED)

  		return;

  	context->serial     = 0;

  	context->ctime      = CURRENT_TIME;
  	context->in_syscall = 1;

  	context->current_state  = state;

  	context->ppid       = 0;

  }

  /**
   * audit_syscall_exit - deallocate audit context after a system call

   * @success: success value of the syscall
   * @return_code: return value of the syscall

   *
   * Tear down after system call.  If the audit context has been marked as

   * auditable (either because of the AUDIT_RECORD_CONTEXT state from

   * filtering, or because some other part of the kernel wrote an audit

   * message), then write out the syscall information.  In call cases,

   * free the names stored from getname().
   */

  void __audit_syscall_exit(int success, long return_code)

  {

  	struct task_struct *tsk = current;

  	struct audit_context *context;

  	if (success)
  		success = AUDITSC_SUCCESS;
  	else
  		success = AUDITSC_FAILURE;

  	context = audit_get_context(tsk, success, return_code);

  	if (!context)

  		return;

  	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)

  		audit_log_exit(context, tsk);

  
  	context->in_syscall = 0;

  	context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;

  	if (!list_empty(&context->killed_trees))
  		audit_kill_trees(&context->killed_trees);

  	audit_free_names(context);
  	unroll_tree_refs(context, NULL, 0);
  	audit_free_aux(context);
  	context->aux = NULL;
  	context->aux_pids = NULL;
  	context->target_pid = 0;
  	context->target_sid = 0;
  	context->sockaddr_len = 0;
  	context->type = 0;
  	context->fds[0] = -1;
  	if (context->state != AUDIT_RECORD_CONTEXT) {
  		kfree(context->filterkey);
  		context->filterkey = NULL;

  	}

  	tsk->audit_context = context;

  }

  static inline void handle_one(const struct inode *inode)
  {
  #ifdef CONFIG_AUDIT_TREE
  	struct audit_context *context;
  	struct audit_tree_refs *p;
  	struct audit_chunk *chunk;
  	int count;

  	if (likely(hlist_empty(&inode->i_fsnotify_marks)))

  		return;
  	context = current->audit_context;
  	p = context->trees;
  	count = context->tree_count;
  	rcu_read_lock();
  	chunk = audit_tree_lookup(inode);
  	rcu_read_unlock();
  	if (!chunk)
  		return;
  	if (likely(put_tree_ref(context, chunk)))
  		return;
  	if (unlikely(!grow_tree_refs(context))) {

  		printk(KERN_WARNING "out of memory, audit has lost a tree reference
  ");

  		audit_set_auditable(context);
  		audit_put_chunk(chunk);
  		unroll_tree_refs(context, p, count);
  		return;
  	}
  	put_tree_ref(context, chunk);
  #endif
  }
  
  static void handle_path(const struct dentry *dentry)
  {
  #ifdef CONFIG_AUDIT_TREE
  	struct audit_context *context;
  	struct audit_tree_refs *p;
  	const struct dentry *d, *parent;
  	struct audit_chunk *drop;
  	unsigned long seq;
  	int count;
  
  	context = current->audit_context;
  	p = context->trees;
  	count = context->tree_count;
  retry:
  	drop = NULL;
  	d = dentry;
  	rcu_read_lock();
  	seq = read_seqbegin(&rename_lock);
  	for(;;) {
  		struct inode *inode = d->d_inode;

  		if (inode && unlikely(!hlist_empty(&inode->i_fsnotify_marks))) {

  			struct audit_chunk *chunk;
  			chunk = audit_tree_lookup(inode);
  			if (chunk) {
  				if (unlikely(!put_tree_ref(context, chunk))) {
  					drop = chunk;
  					break;
  				}
  			}
  		}
  		parent = d->d_parent;
  		if (parent == d)
  			break;
  		d = parent;
  	}
  	if (unlikely(read_seqretry(&rename_lock, seq) || drop)) {  /* in this order */
  		rcu_read_unlock();
  		if (!drop) {
  			/* just a race with rename */
  			unroll_tree_refs(context, p, count);
  			goto retry;
  		}
  		audit_put_chunk(drop);
  		if (grow_tree_refs(context)) {
  			/* OK, got more space */
  			unroll_tree_refs(context, p, count);
  			goto retry;
  		}
  		/* too bad */
  		printk(KERN_WARNING

  			"out of memory, audit has lost a tree reference
  ");

  		unroll_tree_refs(context, p, count);
  		audit_set_auditable(context);
  		return;
  	}
  	rcu_read_unlock();
  #endif
  }

  static struct audit_names *audit_alloc_name(struct audit_context *context,
  						unsigned char type)

  {
  	struct audit_names *aname;
  
  	if (context->name_count < AUDIT_NAMES) {
  		aname = &context->preallocated_names[context->name_count];
  		memset(aname, 0, sizeof(*aname));
  	} else {
  		aname = kzalloc(sizeof(*aname), GFP_NOFS);
  		if (!aname)
  			return NULL;
  		aname->should_free = true;
  	}
  
  	aname->ino = (unsigned long)-1;

  	aname->type = type;

  	list_add_tail(&aname->list, &context->names_list);
  
  	context->name_count++;
  #if AUDIT_DEBUG
  	context->ino_count++;
  #endif
  	return aname;
  }

  /**

   * audit_reusename - fill out filename with info from existing entry
   * @uptr: userland ptr to pathname
   *
   * Search the audit_names list for the current audit context. If there is an
   * existing entry with a matching "uptr" then return the filename
   * associated with that audit_name. If not, return NULL.
   */
  struct filename *
  __audit_reusename(const __user char *uptr)
  {
  	struct audit_context *context = current->audit_context;
  	struct audit_names *n;
  
  	list_for_each_entry(n, &context->names_list, list) {
  		if (!n->name)
  			continue;
  		if (n->name->uptr == uptr)
  			return n->name;
  	}
  	return NULL;
  }
  
  /**

   * audit_getname - add a name to the list
   * @name: name to add
   *
   * Add a name to the list of audit names for this context.
   * Called from fs/namei.c:getname().
   */

  void __audit_getname(struct filename *name)

  {
  	struct audit_context *context = current->audit_context;

  	struct audit_names *n;

  	if (!context->in_syscall) {
  #if AUDIT_DEBUG == 2
  		printk(KERN_ERR "%s:%d(:%d): ignoring getname(%p)
  ",
  		       __FILE__, __LINE__, context->serial, name);
  		dump_stack();
  #endif
  		return;
  	}

  #if AUDIT_DEBUG
  	/* The filename _must_ have a populated ->name */
  	BUG_ON(!name->name);
  #endif

  	n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);

  	if (!n)
  		return;
  
  	n->name = name;
  	n->name_len = AUDIT_NAME_FULL;
  	n->name_put = true;

  	name->aname = n;

  	if (!context->pwd.dentry)
  		get_fs_pwd(current->fs, &context->pwd);

  }

  /* audit_putname - intercept a putname request
   * @name: name to intercept and delay for putname
   *
   * If we have stored the name from getname in the audit context,
   * then we delay the putname until syscall exit.
   * Called from include/linux/fs.h:putname().
   */

  void audit_putname(struct filename *name)

  {
  	struct audit_context *context = current->audit_context;
  
  	BUG_ON(!context);
  	if (!context->in_syscall) {
  #if AUDIT_DEBUG == 2

  		printk(KERN_ERR "%s:%d(:%d): final_putname(%p)
  ",

  		       __FILE__, __LINE__, context->serial, name);
  		if (context->name_count) {

  			struct audit_names *n;

  			int i = 0;

  
  			list_for_each_entry(n, &context->names_list, list)

  				printk(KERN_ERR "name[%d] = %p = %s
  ", i++,

  				       n->name, n->name->name ?: "(null)");

  			}

  #endif

  		final_putname(name);

  	}
  #if AUDIT_DEBUG
  	else {
  		++context->put_count;
  		if (context->put_count > context->name_count) {
  			printk(KERN_ERR "%s:%d(:%d): major=%d"
  			       " in_syscall=%d putname(%p) name_count=%d"
  			       " put_count=%d
  ",
  			       __FILE__, __LINE__,
  			       context->serial, context->major,

  			       context->in_syscall, name->name,
  			       context->name_count, context->put_count);

  			dump_stack();
  		}
  	}
  #endif
  }

  /**

   * __audit_inode - store the inode and device from a lookup

   * @name: name being audited

   * @dentry: dentry being audited

   * @parent: does this dentry represent the parent?

   */

  void __audit_inode(struct filename *name, const struct dentry *dentry,

  		   unsigned int parent)

  {

  	struct audit_context *context = current->audit_context;

  	const struct inode *inode = dentry->d_inode;

  	struct audit_names *n;

  
  	if (!context->in_syscall)
  		return;

  	if (!name)
  		goto out_alloc;

  #if AUDIT_DEBUG
  	/* The struct filename _must_ have a populated ->name */
  	BUG_ON(!name->name);
  #endif
  	/*
  	 * If we have a pointer to an audit_names entry already, then we can
  	 * just use it directly if the type is correct.
  	 */
  	n = name->aname;
  	if (n) {
  		if (parent) {
  			if (n->type == AUDIT_TYPE_PARENT ||
  			    n->type == AUDIT_TYPE_UNKNOWN)
  				goto out;
  		} else {
  			if (n->type != AUDIT_TYPE_PARENT)
  				goto out;
  		}
  	}

  	list_for_each_entry_reverse(n, &context->names_list, list) {

  		/* does the name pointer match? */

  		if (!n->name || n->name->name != name->name)

  			continue;
  
  		/* match the correct record type */
  		if (parent) {
  			if (n->type == AUDIT_TYPE_PARENT ||
  			    n->type == AUDIT_TYPE_UNKNOWN)
  				goto out;
  		} else {
  			if (n->type != AUDIT_TYPE_PARENT)
  				goto out;
  		}

  	}

  out_alloc:

  	/* unable to find the name from a previous getname(). Allocate a new
  	 * anonymous entry.
  	 */

  	n = audit_alloc_name(context, AUDIT_TYPE_NORMAL);

  	if (!n)
  		return;
  out:

  	if (parent) {

  		n->name_len = n->name ? parent_len(n->name->name) : AUDIT_NAME_FULL;

  		n->type = AUDIT_TYPE_PARENT;
  	} else {
  		n->name_len = AUDIT_NAME_FULL;
  		n->type = AUDIT_TYPE_NORMAL;
  	}

  	handle_path(dentry);

  	audit_copy_inode(n, dentry, inode);

  }
  
  /**

   * __audit_inode_child - collect inode info for created/removed objects

   * @parent: inode of dentry parent

   * @dentry: dentry being audited

   * @type:   AUDIT_TYPE_* value that we're looking for

   *
   * For syscalls that create or remove filesystem objects, audit_inode
   * can only collect information for the filesystem object's parent.
   * This call updates the audit context with the child's information.
   * Syscalls that create a new filesystem object must be hooked after
   * the object is created.  Syscalls that remove a filesystem object
   * must be hooked prior, in order to capture the target inode during
   * unsuccessful attempts.
   */

  void __audit_inode_child(const struct inode *parent,