merge task_work and rcu_head, get rid of separate allocation for keyring case
task_work and rcu_head are identical now; merge them (calling the result
struct callback_head, rcu_head #define'd to it), kill separate allocation
in security/keys since we can just use cred->rcu now.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index b9216eb..af3555c 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1405,7 +1405,7 @@
int (*notifier)(void *priv);
void *notifier_data;
sigset_t *notifier_mask;
- void *task_works;
+ struct callback_head *task_works;
struct audit_context *audit_context;
#ifdef CONFIG_AUDITSYSCALL
diff --git a/include/linux/task_work.h b/include/linux/task_work.h
index 3b3e2c8..fb46b03 100644
--- a/include/linux/task_work.h
+++ b/include/linux/task_work.h
@@ -4,22 +4,16 @@
#include <linux/list.h>
#include <linux/sched.h>
-struct task_work;
-typedef void (*task_work_func_t)(struct task_work *);
-
-struct task_work {
- struct task_work *next;
- task_work_func_t func;
-};
+typedef void (*task_work_func_t)(struct callback_head *);
static inline void
-init_task_work(struct task_work *twork, task_work_func_t func)
+init_task_work(struct callback_head *twork, task_work_func_t func)
{
twork->func = func;
}
-int task_work_add(struct task_struct *task, struct task_work *twork, bool);
-struct task_work *task_work_cancel(struct task_struct *, task_work_func_t);
+int task_work_add(struct task_struct *task, struct callback_head *twork, bool);
+struct callback_head *task_work_cancel(struct task_struct *, task_work_func_t);
void task_work_run(void);
static inline void exit_task_work(struct task_struct *task)
diff --git a/include/linux/types.h b/include/linux/types.h
index 9c1bd53..bf0dd75 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -246,14 +246,15 @@
};
/**
- * struct rcu_head - callback structure for use with RCU
+ * struct callback_head - callback structure for use with RCU and task_work
* @next: next update requests in a list
* @func: actual update function to call after the grace period.
*/
-struct rcu_head {
- struct rcu_head *next;
- void (*func)(struct rcu_head *head);
+struct callback_head {
+ struct callback_head *next;
+ void (*func)(struct callback_head *head);
};
+#define rcu_head callback_head
#endif /* __KERNEL__ */
#endif /* __ASSEMBLY__ */
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index d1dd547..814c9ef 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -781,7 +781,7 @@
wake_up(&desc->wait_for_threads);
}
-static void irq_thread_dtor(struct task_work *unused)
+static void irq_thread_dtor(struct callback_head *unused)
{
struct task_struct *tsk = current;
struct irq_desc *desc;
@@ -813,7 +813,7 @@
*/
static int irq_thread(void *data)
{
- struct task_work on_exit_work;
+ struct callback_head on_exit_work;
static const struct sched_param param = {
.sched_priority = MAX_USER_RT_PRIO/2,
};
diff --git a/kernel/task_work.c b/kernel/task_work.c
index 9b8948d..76266fb 100644
--- a/kernel/task_work.c
+++ b/kernel/task_work.c
@@ -3,7 +3,7 @@
#include <linux/tracehook.h>
int
-task_work_add(struct task_struct *task, struct task_work *twork, bool notify)
+task_work_add(struct task_struct *task, struct callback_head *twork, bool notify)
{
unsigned long flags;
int err = -ESRCH;
@@ -19,8 +19,8 @@
*/
raw_spin_lock_irqsave(&task->pi_lock, flags);
if (likely(!(task->flags & PF_EXITING))) {
- struct task_work *last = task->task_works;
- struct task_work *first = last ? last->next : twork;
+ struct callback_head *last = task->task_works;
+ struct callback_head *first = last ? last->next : twork;
twork->next = first;
if (last)
last->next = twork;
@@ -35,16 +35,16 @@
return err;
}
-struct task_work *
+struct callback_head *
task_work_cancel(struct task_struct *task, task_work_func_t func)
{
unsigned long flags;
- struct task_work *last, *res = NULL;
+ struct callback_head *last, *res = NULL;
raw_spin_lock_irqsave(&task->pi_lock, flags);
last = task->task_works;
if (last) {
- struct task_work *q = last, *p = q->next;
+ struct callback_head *q = last, *p = q->next;
while (1) {
if (p->func == func) {
q->next = p->next;
@@ -66,7 +66,7 @@
void task_work_run(void)
{
struct task_struct *task = current;
- struct task_work *p, *q;
+ struct callback_head *p, *q;
raw_spin_lock_irq(&task->pi_lock);
p = task->task_works;
diff --git a/security/keys/internal.h b/security/keys/internal.h
index b510a31..c246ba5 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -148,12 +148,8 @@
#define KEY_LOOKUP_PARTIAL 0x02
#define KEY_LOOKUP_FOR_UNLINK 0x04
-struct kludge { /* this will die off very soon */
- struct task_work twork;
- struct cred *cred;
-};
extern long join_session_keyring(const char *name);
-extern void key_change_session_keyring(struct task_work *twork);
+extern void key_change_session_keyring(struct callback_head *twork);
extern struct work_struct key_gc_work;
extern unsigned key_gc_delay;
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 26723ca..0291b3f 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1456,8 +1456,7 @@
{
struct task_struct *me, *parent;
const struct cred *mycred, *pcred;
- struct kludge *newwork;
- struct task_work *oldwork;
+ struct callback_head *newwork, *oldwork;
key_ref_t keyring_r;
struct cred *cred;
int ret;
@@ -1467,20 +1466,17 @@
return PTR_ERR(keyring_r);
ret = -ENOMEM;
- newwork = kmalloc(sizeof(struct kludge), GFP_KERNEL);
- if (!newwork)
- goto error_keyring;
/* our parent is going to need a new cred struct, a new tgcred struct
* and new security data, so we allocate them here to prevent ENOMEM in
* our parent */
cred = cred_alloc_blank();
if (!cred)
- goto error_newwork;
+ goto error_keyring;
+ newwork = &cred->rcu;
cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r);
- init_task_work(&newwork->twork, key_change_session_keyring);
- newwork->cred = cred;
+ init_task_work(newwork, key_change_session_keyring);
me = current;
rcu_read_lock();
@@ -1529,24 +1525,18 @@
/* the replacement session keyring is applied just prior to userspace
* restarting */
- ret = task_work_add(parent, &newwork->twork, true);
+ ret = task_work_add(parent, newwork, true);
if (!ret)
newwork = NULL;
unlock:
write_unlock_irq(&tasklist_lock);
rcu_read_unlock();
- if (oldwork) {
- put_cred(container_of(oldwork, struct kludge, twork)->cred);
- kfree(oldwork);
- }
- if (newwork) {
- put_cred(newwork->cred);
- kfree(newwork);
- }
+ if (oldwork)
+ put_cred(container_of(oldwork, struct cred, rcu));
+ if (newwork)
+ put_cred(cred);
return ret;
-error_newwork:
- kfree(newwork);
error_keyring:
key_ref_put(keyring_r);
return ret;
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index c9b07c9..54339cf 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -834,13 +834,11 @@
* Replace a process's session keyring on behalf of one of its children when
* the target process is about to resume userspace execution.
*/
-void key_change_session_keyring(struct task_work *twork)
+void key_change_session_keyring(struct callback_head *twork)
{
const struct cred *old = current_cred();
- struct kludge *p = container_of(twork, struct kludge, twork);
- struct cred *new = p->cred;
+ struct cred *new = container_of(twork, struct cred, rcu);
- kfree(p);
if (unlikely(current->flags & PF_EXITING)) {
put_cred(new);
return;