| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <4628DA30.809@fr.ibm.com>
Date: Fri, 20 Apr 2007 17:20:16 +0200
From: Cedric Le Goater <clg@...ibm.com>
To: devel@...nvz.org
CC: "Eric W. Biederman" <ebiederm@...ssion.com>,
Christoph@...p2.linux-foundation.org,
Holtmann <marcel@...tmann.org>, linux-kernel@...r.kernel.org,
Hellwig <hch@...radead.org>, containers@...ts.osdl.org,
Marcel@...p2.linux-foundation.org, Oleg Nesterov <oleg@...sign.ru>
Subject: Re: [Devel] Re: [PATCH] bluetooth rfcomm: Convert to kthread API.
Andrew Morton wrote:
> On Thu, 19 Apr 2007 01:58:54 -0600
> "Eric W. Biederman" <ebiederm@...ssion.com> wrote:
>
>> From: Eric W. Biederman <ebiederm@...ssion.com>
>>
>> This patch starts krfcommd using kthread_run instead of a combination
>> of kernel_thread and daemonize making the code slightly simpler
>> and more maintainable.
>
> gargh, the more I look at these things, the more I agree with Christoph.
>
>> Cc: Marcel Holtmann <marcel@...tmann.org>
>> Signed-off-by: Eric W. Biederman <ebiederm@...ssion.com>
>> ---
>> net/bluetooth/rfcomm/core.c | 4 ++--
>> 1 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
>> index 34f993a..baaad49 100644
>> --- a/net/bluetooth/rfcomm/core.c
>> +++ b/net/bluetooth/rfcomm/core.c
>> @@ -38,6 +38,7 @@
>> #include <linux/net.h>
>> #include <linux/mutex.h>
>> #include <linux/freezer.h>
>> +#include <linux/kthread.h>
>>
>> #include <net/sock.h>
>> #include <asm/uaccess.h>
>> @@ -1938,7 +1939,6 @@ static int rfcomm_run(void *unused)
>>
>> atomic_inc(&running);
>>
>> - daemonize("krfcommd");
>> set_user_nice(current, -10);
>>
>> BT_DBG("");
>> @@ -2058,7 +2058,7 @@ static int __init rfcomm_init(void)
>>
>> hci_register_cb(&rfcomm_cb);
>>
>> - kernel_thread(rfcomm_run, NULL, CLONE_KERNEL);
>> + kthread_run(rfcomm_run, NULL, "krfcommd");
>>
>> if (class_create_file(bt_class, &class_attr_rfcomm_dlc) < 0)
>> BT_ERR("Failed to create RFCOMM info file");
>
> We should remove the file-wide `terminate' and `running' and switch the
> thread management over to kthread_run(), kthread_stop() and
> kthread_should_stop().
here's an old refreshed one using kthread_stop() and fixing the racy
wakeup.
C.
Signed-off-by: Cedric Le Goater <clg@...ibm.com>
---
net/bluetooth/rfcomm/core.c | 61 +++++++++++++++-----------------------------
1 file changed, 21 insertions(+), 40 deletions(-)
Index: 2.6.21-rc6-mm1/net/bluetooth/rfcomm/core.c
===================================================================
--- 2.6.21-rc6-mm1.orig/net/bluetooth/rfcomm/core.c
+++ 2.6.21-rc6-mm1/net/bluetooth/rfcomm/core.c
@@ -38,6 +38,7 @@
#include <linux/net.h>
#include <linux/mutex.h>
#include <linux/freezer.h>
+#include <linux/kthread.h>
#include <net/sock.h>
#include <asm/uaccess.h>
@@ -68,7 +69,6 @@ static DEFINE_MUTEX(rfcomm_mutex);
static unsigned long rfcomm_event;
static LIST_HEAD(session_list);
-static atomic_t terminate, running;
static int rfcomm_send_frame(struct rfcomm_session *s, u8 *data, int len);
static int rfcomm_send_sabm(struct rfcomm_session *s, u8 dlci);
@@ -1847,28 +1847,6 @@ static inline void rfcomm_process_sessio
rfcomm_unlock();
}
-static void rfcomm_worker(void)
-{
- BT_DBG("");
-
- while (!atomic_read(&terminate)) {
- try_to_freeze();
-
- if (!test_bit(RFCOMM_SCHED_WAKEUP, &rfcomm_event)) {
- /* No pending events. Let's sleep.
- * Incoming connections and data will wake us up. */
- set_current_state(TASK_INTERRUPTIBLE);
- schedule();
- }
-
- /* Process stuff */
- clear_bit(RFCOMM_SCHED_WAKEUP, &rfcomm_event);
- rfcomm_process_sessions();
- }
- set_current_state(TASK_RUNNING);
- return;
-}
-
static int rfcomm_add_listener(bdaddr_t *ba)
{
struct sockaddr_l2 addr;
@@ -1934,22 +1912,29 @@ static void rfcomm_kill_listener(void)
static int rfcomm_run(void *unused)
{
- rfcomm_thread = current;
-
- atomic_inc(&running);
-
- daemonize("krfcommd");
set_user_nice(current, -10);
BT_DBG("");
rfcomm_add_listener(BDADDR_ANY);
- rfcomm_worker();
+ while (!kthread_should_stop()) {
+ try_to_freeze();
- rfcomm_kill_listener();
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (!test_bit(RFCOMM_SCHED_WAKEUP, &rfcomm_event)) {
+ /* No pending events. Let's sleep.
+ * Incoming connections and data will wake us up. */
+ schedule();
+ }
- atomic_dec(&running);
+ /* Process stuff */
+ clear_bit(RFCOMM_SCHED_WAKEUP, &rfcomm_event);
+ rfcomm_process_sessions();
+ }
+ set_current_state(TASK_RUNNING);
+
+ rfcomm_kill_listener();
return 0;
}
@@ -2058,7 +2043,9 @@ static int __init rfcomm_init(void)
hci_register_cb(&rfcomm_cb);
- kernel_thread(rfcomm_run, NULL, CLONE_KERNEL);
+ rfcomm_thread = kthread_run(rfcomm_run, NULL, "krfcommd");
+ if (IS_ERR(rfcomm_thread))
+ return PTR_ERR(rfcomm_thread);
if (class_create_file(bt_class, &class_attr_rfcomm_dlc) < 0)
BT_ERR("Failed to create RFCOMM info file");
@@ -2080,14 +2067,8 @@ static void __exit rfcomm_exit(void)
hci_unregister_cb(&rfcomm_cb);
- /* Terminate working thread.
- * ie. Set terminate flag and wake it up */
- atomic_inc(&terminate);
- rfcomm_schedule(RFCOMM_SCHED_STATE);
-
- /* Wait until thread is running */
- while (atomic_read(&running))
- schedule();
+ /* Terminate working thread */
+ kthread_stop(rfcomm_thread);
#ifdef CONFIG_BT_RFCOMM_TTY
rfcomm_cleanup_ttys();
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists