TOMOYO: Allow reading only execute permission.

Policy editor needs to know allow_execute entries in order to build domain
transition tree. Reading all entries is slow. Thus, allow reading only
allow_execute entries.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

2 files changed, 10 insertions, 0 deletions

diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index 2a5330ec06c9..6c68981c0f5f 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -594,6 +594,10 @@ static bool tomoyo_select_one(struct tomoyo_io_buffer *head, const char *data)
         struct tomoyo_domain_info *domain = NULL;
         bool global_pid = false;
 
+        if (!strcmp(data, "allow_execute")) {
+                head->print_execute_only = true;
+                return true;
+        }
         if (sscanf(data, "pid=%u", &pid) == 1 ||
             (global_pid = true, sscanf(data, "global-pid=%u", &pid) == 1)) {
                 struct task_struct *p;
@@ -759,6 +763,8 @@ static bool tomoyo_print_path_acl(struct tomoyo_io_buffer *head,
         for (bit = head->read_bit; bit < TOMOYO_MAX_PATH_OPERATION; bit++) {
                 if (!(perm & (1 << bit)))
                         continue;
+                if (head->print_execute_only && bit != TOMOYO_TYPE_EXECUTE)
+                        continue;
                 /* Print "read/write" instead of "read" and "write". */
                 if ((bit == TOMOYO_TYPE_READ || bit == TOMOYO_TYPE_WRITE)
                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE)))
@@ -926,6 +932,8 @@ static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
                         = container_of(ptr, struct tomoyo_path_acl, head);
                 return tomoyo_print_path_acl(head, acl);
         }
+        if (head->print_execute_only)
+                return true;
         if (acl_type == TOMOYO_TYPE_PATH2_ACL) {
                 struct tomoyo_path2_acl *acl
                         = container_of(ptr, struct tomoyo_path2_acl, head);
diff --git a/security/tomoyo/common.h b/security/tomoyo/common.h
index cdc9ef56fd86..67b9aeae80a7 100644
--- a/security/tomoyo/common.h
+++ b/security/tomoyo/common.h
@@ -571,6 +571,8 @@ struct tomoyo_io_buffer {
         bool read_single_domain;
         /* Extra variable for reading.          */
         u8 read_bit;
+        /* Read only TOMOYO_TYPE_EXECUTE        */
+        bool print_execute_only;
         /* Bytes available for reading.         */
         int read_avail;
         /* Size of read buffer.                 */