TOMOYO: Extract bitfield
Tetsuo Handa [Tue, 2 Feb 2010 21:43:06 +0000 (06:43 +0900)]
Since list elements are rounded up to kmalloc() size rather than sizeof(int),
saving one byte by using bitfields is no longer helpful.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

security/tomoyo/common.c
security/tomoyo/common.h
security/tomoyo/domain.c
security/tomoyo/file.c

index ef66223..ae3ed73 100644 (file)
@@ -842,9 +842,7 @@ bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain)
        if (!domain)
                return true;
        list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
-               if (ptr->type & TOMOYO_ACL_DELETED)
-                       continue;
-               switch (tomoyo_acl_type2(ptr)) {
+               switch (ptr->type) {
                        struct tomoyo_single_path_acl_record *acl;
                        u32 perm;
                        u8 i;
@@ -1384,8 +1382,7 @@ static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
                return 0;
        }
        if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
-               tomoyo_set_domain_flag(domain, is_delete,
-                              TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ);
+               domain->ignore_global_allow_read = !is_delete;
                return 0;
        }
        return tomoyo_write_file_policy(data, domain, is_delete);
@@ -1486,10 +1483,8 @@ static bool tomoyo_print_double_path_acl(struct tomoyo_io_buffer *head,
 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
                               struct tomoyo_acl_info *ptr)
 {
-       const u8 acl_type = tomoyo_acl_type2(ptr);
+       const u8 acl_type = ptr->type;
 
-       if (acl_type & TOMOYO_ACL_DELETED)
-               return true;
        if (acl_type == TOMOYO_TYPE_SINGLE_PATH_ACL) {
                struct tomoyo_single_path_acl_record *acl
                        = container_of(ptr,
@@ -1540,10 +1535,9 @@ static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
                /* Print domainname and flags. */
                if (domain->quota_warned)
                        quota_exceeded = "quota_exceeded\n";
-               if (domain->flags & TOMOYO_DOMAIN_FLAGS_TRANSITION_FAILED)
+               if (domain->transition_failed)
                        transition_failed = "transition_failed\n";
-               if (domain->flags &
-                   TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ)
+               if (domain->ignore_global_allow_read)
                        ignore_global_allow_read
                                = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
                done = tomoyo_io_printf(head, "%s\n" TOMOYO_KEYWORD_USE_PROFILE
index 8b59ec8..509ced9 100644 (file)
@@ -101,11 +101,9 @@ struct tomoyo_path_info_with_data {
  *
  *  (1) "list" which is linked to the ->acl_info_list of
  *      "struct tomoyo_domain_info"
- *  (2) "type" which tells
- *      (a) type & 0x7F : type of the entry (either
- *          "struct tomoyo_single_path_acl_record" or
- *          "struct tomoyo_double_path_acl_record")
- *      (b) type & 0x80 : whether the entry is marked as "deleted".
+ *  (2) "type" which tells type of the entry (either
+ *      "struct tomoyo_single_path_acl_record" or
+ *      "struct tomoyo_double_path_acl_record").
  *
  * Packing "struct tomoyo_acl_info" allows
  * "struct tomoyo_single_path_acl_record" to embed "u8" + "u16" and
@@ -114,17 +112,9 @@ struct tomoyo_path_info_with_data {
  */
 struct tomoyo_acl_info {
        struct list_head list;
-       /*
-        * Type of this ACL entry.
-        *
-        * MSB is is_deleted flag.
-        */
        u8 type;
 } __packed;
 
-/* This ACL entry is deleted.           */
-#define TOMOYO_ACL_DELETED        0x80
-
 /*
  * tomoyo_domain_info is a structure which is used for holding permissions
  * (e.g. "allow_read /lib/libc-2.5.so") given to each domain.
@@ -138,7 +128,13 @@ struct tomoyo_acl_info {
  *      "deleted", false otherwise.
  *  (6) "quota_warned" is a bool which is used for suppressing warning message
  *      when learning mode learned too much entries.
- *  (7) "flags" which remembers this domain's attributes.
+ *  (7) "ignore_global_allow_read" is a bool which is true if this domain
+ *      should ignore "allow_read" directive in exception policy.
+ *  (8) "transition_failed" is a bool which is set to true when this domain was
+ *      unable to create a new domain at tomoyo_find_next_domain() because the
+ *      name of the domain to be created was too long or it could not allocate
+ *      memory. If set to true, more than one process continued execve()
+ *      without domain transition.
  *
  * A domain's lifecycle is an analogy of files on / directory.
  * Multiple domains with the same domainname cannot be created (as with
@@ -155,23 +151,13 @@ struct tomoyo_domain_info {
        u8 profile;        /* Profile number to use. */
        bool is_deleted;   /* Delete flag.           */
        bool quota_warned; /* Quota warnning flag.   */
-       /* DOMAIN_FLAGS_*. Use tomoyo_set_domain_flag() to modify. */
-       u8 flags;
+       bool ignore_global_allow_read; /* Ignore "allow_read" flag. */
+       bool transition_failed; /* Domain transition failed flag. */
 };
 
 /* Profile number is an integer between 0 and 255. */
 #define TOMOYO_MAX_PROFILES 256
 
-/* Ignore "allow_read" directive in exception policy. */
-#define TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ 1
-/*
- * This domain was unable to create a new domain at tomoyo_find_next_domain()
- * because the name of the domain to be created was too long or
- * it could not allocate memory.
- * More than one process continued execve() without domain transition.
- */
-#define TOMOYO_DOMAIN_FLAGS_TRANSITION_FAILED        2
-
 /*
  * tomoyo_single_path_acl_record is a structure which is used for holding an
  * entry with one pathname operation (e.g. open(), mkdir()).
@@ -380,9 +366,6 @@ unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr);
 /* Run policy loader when /sbin/init starts. */
 void tomoyo_load_policy(const char *filename);
-/* Change "struct tomoyo_domain_info"->flags. */
-void tomoyo_set_domain_flag(struct tomoyo_domain_info *domain,
-                           const bool is_delete, const u8 flags);
 
 /* strcmp() for "struct tomoyo_path_info" structure. */
 static inline bool tomoyo_pathcmp(const struct tomoyo_path_info *a,
@@ -391,18 +374,6 @@ static inline bool tomoyo_pathcmp(const struct tomoyo_path_info *a,
        return a->hash != b->hash || strcmp(a->name, b->name);
 }
 
-/* Get type of an ACL entry. */
-static inline u8 tomoyo_acl_type1(struct tomoyo_acl_info *ptr)
-{
-       return ptr->type & ~TOMOYO_ACL_DELETED;
-}
-
-/* Get type of an ACL entry. */
-static inline u8 tomoyo_acl_type2(struct tomoyo_acl_info *ptr)
-{
-       return ptr->type;
-}
-
 /**
  * tomoyo_is_valid - Check whether the character is a valid char.
  *
index 3484397..ec612ae 100644 (file)
@@ -130,28 +130,6 @@ struct tomoyo_alias_entry {
 };
 
 /**
- * tomoyo_set_domain_flag - Set or clear domain's attribute flags.
- *
- * @domain:    Pointer to "struct tomoyo_domain_info".
- * @is_delete: True if it is a delete request.
- * @flags:     Flags to set or clear.
- *
- * Returns nothing.
- */
-void tomoyo_set_domain_flag(struct tomoyo_domain_info *domain,
-                           const bool is_delete, const u8 flags)
-{
-       /* We need to serialize because this is bitfield operation. */
-       static DEFINE_SPINLOCK(lock);
-       spin_lock(&lock);
-       if (!is_delete)
-               domain->flags |= flags;
-       else
-               domain->flags &= ~flags;
-       spin_unlock(&lock);
-}
-
-/**
  * tomoyo_get_last_name - Get last component of a domainname.
  *
  * @domain: Pointer to "struct tomoyo_domain_info".
@@ -896,8 +874,7 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
        if (is_enforce)
                retval = -EPERM;
        else
-               tomoyo_set_domain_flag(old_domain, false,
-                                      TOMOYO_DOMAIN_FLAGS_TRANSITION_FAILED);
+               old_domain->transition_failed = true;
  out:
        if (!domain)
                domain = old_domain;
index 24af081..84c821a 100644 (file)
@@ -688,7 +688,7 @@ static int tomoyo_check_single_path_acl2(const struct tomoyo_domain_info *
 
        list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
                struct tomoyo_single_path_acl_record *acl;
-               if (tomoyo_acl_type2(ptr) != TOMOYO_TYPE_SINGLE_PATH_ACL)
+               if (ptr->type != TOMOYO_TYPE_SINGLE_PATH_ACL)
                        continue;
                acl = container_of(ptr, struct tomoyo_single_path_acl_record,
                                   head);
@@ -770,8 +770,7 @@ static int tomoyo_check_file_perm2(struct tomoyo_domain_info * const domain,
        if (!filename)
                return 0;
        error = tomoyo_check_file_acl(domain, filename, perm);
-       if (error && perm == 4 &&
-           (domain->flags & TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ) == 0
+       if (error && perm == 4 && !domain->ignore_global_allow_read
            && tomoyo_is_globally_readable_file(filename))
                error = 0;
        if (perm == 6)
@@ -885,15 +884,12 @@ static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
        if (is_delete)
                goto delete;
        list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
-               if (tomoyo_acl_type1(ptr) != TOMOYO_TYPE_SINGLE_PATH_ACL)
+               if (ptr->type != TOMOYO_TYPE_SINGLE_PATH_ACL)
                        continue;
                acl = container_of(ptr, struct tomoyo_single_path_acl_record,
                                   head);
                if (acl->filename != saved_filename)
                        continue;
-               /* Special case. Clear all bits if marked as deleted. */
-               if (ptr->type & TOMOYO_ACL_DELETED)
-                       acl->perm = 0;
                if (perm <= 0xFFFF)
                        acl->perm |= perm;
                else
@@ -902,7 +898,6 @@ static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
                        acl->perm |= 1 << TOMOYO_TYPE_READ_WRITE_ACL;
                else if (acl->perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL))
                        acl->perm |= rw_mask;
-               ptr->type &= ~TOMOYO_ACL_DELETED;
                error = 0;
                goto out;
        }
@@ -927,7 +922,7 @@ static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
  delete:
        error = -ENOENT;
        list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
-               if (tomoyo_acl_type2(ptr) != TOMOYO_TYPE_SINGLE_PATH_ACL)
+               if (ptr->type != TOMOYO_TYPE_SINGLE_PATH_ACL)
                        continue;
                acl = container_of(ptr, struct tomoyo_single_path_acl_record,
                                   head);
@@ -941,8 +936,6 @@ static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
                        acl->perm &= ~(1 << TOMOYO_TYPE_READ_WRITE_ACL);
                else if (!(acl->perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL)))
                        acl->perm &= ~rw_mask;
-               if (!acl->perm && !acl->perm_high)
-                       ptr->type |= TOMOYO_ACL_DELETED;
                error = 0;
                break;
        }
@@ -989,18 +982,14 @@ static int tomoyo_update_double_path_acl(const u8 type, const char *filename1,
        if (is_delete)
                goto delete;
        list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
-               if (tomoyo_acl_type1(ptr) != TOMOYO_TYPE_DOUBLE_PATH_ACL)
+               if (ptr->type != TOMOYO_TYPE_DOUBLE_PATH_ACL)
                        continue;
                acl = container_of(ptr, struct tomoyo_double_path_acl_record,
                                   head);
                if (acl->filename1 != saved_filename1 ||
                    acl->filename2 != saved_filename2)
                        continue;
-               /* Special case. Clear all bits if marked as deleted. */
-               if (ptr->type & TOMOYO_ACL_DELETED)
-                       acl->perm = 0;
                acl->perm |= perm;
-               ptr->type &= ~TOMOYO_ACL_DELETED;
                error = 0;
                goto out;
        }
@@ -1021,7 +1010,7 @@ static int tomoyo_update_double_path_acl(const u8 type, const char *filename1,
  delete:
        error = -ENOENT;
        list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
-               if (tomoyo_acl_type2(ptr) != TOMOYO_TYPE_DOUBLE_PATH_ACL)
+               if (ptr->type != TOMOYO_TYPE_DOUBLE_PATH_ACL)
                        continue;
                acl = container_of(ptr, struct tomoyo_double_path_acl_record,
                                   head);
@@ -1029,8 +1018,6 @@ static int tomoyo_update_double_path_acl(const u8 type, const char *filename1,
                    acl->filename2 != saved_filename2)
                        continue;
                acl->perm &= ~perm;
-               if (!acl->perm)
-                       ptr->type |= TOMOYO_ACL_DELETED;
                error = 0;
                break;
        }
@@ -1086,7 +1073,7 @@ static int tomoyo_check_double_path_acl(const struct tomoyo_domain_info *domain,
                return 0;
        list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
                struct tomoyo_double_path_acl_record *acl;
-               if (tomoyo_acl_type2(ptr) != TOMOYO_TYPE_DOUBLE_PATH_ACL)
+               if (ptr->type != TOMOYO_TYPE_DOUBLE_PATH_ACL)
                        continue;
                acl = container_of(ptr, struct tomoyo_double_path_acl_record,
                                   head);