TOMOYO: Copy directly to userspace buffer.

When userspace program reads policy from /sys/kernel/security/tomoyo/
interface, TOMOYO uses line buffered mode. A line has at least one word.

Commit 006dacc "TOMOYO: Support longer pathname." changed a word's max length
from 4000 bytes to max kmalloc()able bytes. By that commit, a line's max length
changed from 8192 bytes to more than max kmalloc()able bytes.

Max number of words in a line remains finite. This patch changes the way of
buffering so that all words in a line are firstly directly copied to userspace
buffer as much as possible and are secondly queued for next read request.
Words queued are guaranteed to be valid until /sys/kernel/security/tomoyo/
interface is close()d.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/security/tomoyo/memory.c b/security/tomoyo/memory.c
index 95a77599ff98..a4aba4d9ca2e 100644
--- a/security/tomoyo/memory.c
+++ b/security/tomoyo/memory.c
@@ -234,7 +234,7 @@ unsigned int tomoyo_quota_for_query;
  */
 void tomoyo_read_memory_counter(struct tomoyo_io_buffer *head)
 {
-        if (!head->read_eof) {
+        if (!head->r.eof) {
                 const unsigned int policy
                         = atomic_read(&tomoyo_policy_memory_size);
                 const unsigned int query = tomoyo_query_memory_size;
@@ -258,7 +258,7 @@ void tomoyo_read_memory_counter(struct tomoyo_io_buffer *head)
                 tomoyo_io_printf(head, "Query lists:  %10u%s\n", query,
                                  buffer);
                 tomoyo_io_printf(head, "Total:        %10u\n", policy + query);
-                head->read_eof = true;
+                head->r.eof = true;
         }
 }