gh0s7/mckernel
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Reference counting per-thread data

Browse Source 
It is accompanied by the following fixes:
(1) Fix put ppd locations in mcexec_wait_syscall()
(2) Move put ptd to end of mcexec_terminate_thread_unsafe() and mcexec_ret_syscall()
(3) Add debug messages for ptd add/get/put
(4) Fix ptd-add/get/put matching in mcexec_wait_syscall()
    * Skip put when woken-up from wait_event_interruptible() by signal

Change-Id: Ib9be3f5e62a7a370197cb36c9fa7c4d79f44c314
This commit is contained in:
Masamichi Takagi
2018-09-03 19:36:28 +09:00
parent a121ffc785
commit b8bacdd2de
3 changed files with 269 additions and 112 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
executer/kernel/mcctrl/mcctrl.h
View File

@ -228,9 +228,12 @@ struct mcctrl_channel {
};
struct mcctrl_per_thread_data {
struct mcctrl_per_proc_data *ppd;
struct list_head hash;
struct task_struct *task;
void *data;
int tid; /* debug */
atomic_t refcount;
};
#define MCCTRL_PER_THREAD_DATA_HASH_SHIFT 8
@ -447,20 +450,18 @@ struct mcctrl_per_proc_data *mcctrl_get_per_proc_data(
struct mcctrl_usrdata *ud, int pid);
void mcctrl_put_per_proc_data(struct mcctrl_per_proc_data *ppd);
int mcctrl_add_per_thread_data(struct mcctrl_per_proc_data* ppd,
struct task_struct *task, void *data);
int mcctrl_delete_per_thread_data(struct mcctrl_per_proc_data* ppd,
struct task_struct *task);
int mcctrl_add_per_thread_data(struct mcctrl_per_proc_data *ppd, void *data);
void mcctrl_put_per_thread_data_unsafe(struct mcctrl_per_thread_data *ptd);
void mcctrl_put_per_thread_data(struct mcctrl_per_thread_data* ptd);
#ifdef POSTK_DEBUG_ARCH_DEP_56 /* Strange how to use inline declaration fix. */
static inline struct mcctrl_per_thread_data *mcctrl_get_per_thread_data(
struct mcctrl_per_proc_data *ppd, struct task_struct *task)
inline struct mcctrl_per_thread_data *mcctrl_get_per_thread_data(struct mcctrl_per_proc_data *ppd, struct task_struct *task)
{
struct mcctrl_per_thread_data *ptd_iter, *ptd = NULL;
int hash = (((uint64_t)task >> 4) & MCCTRL_PER_THREAD_DATA_HASH_MASK);
unsigned long flags;
/* Check if data for this thread exists and return it */
read_lock_irqsave(&ppd->per_thread_data_hash_lock[hash], flags);
/* Check if data for this thread exists */
write_lock_irqsave(&ppd->per_thread_data_hash_lock[hash], flags);
list_for_each_entry(ptd_iter, &ppd->per_thread_data_hash[hash], hash) {
if (ptd_iter->task == task) {
@ -469,12 +470,21 @@ static inline struct mcctrl_per_thread_data *mcctrl_get_per_thread_data(
}
}
read_unlock_irqrestore(&ppd->per_thread_data_hash_lock[hash], flags);
return ptd ? ptd->data : NULL;
if (ptd) {
if (atomic_read(&ptd->refcount) <= 0) {
printk("%s: ERROR: use-after-free detected (%d)", __FUNCTION__, atomic_read(&ptd->refcount));
ptd = NULL;
goto out;
}
atomic_inc(&ptd->refcount);
}
out:
write_unlock_irqrestore(&ppd->per_thread_data_hash_lock[hash], flags);
return ptd;
}
#else /* POSTK_DEBUG_ARCH_DEP_56 */
inline struct mcctrl_per_thread_data *mcctrl_get_per_thread_data(
struct mcctrl_per_proc_data *ppd, struct task_struct *task);
inline struct mcctrl_per_thread_data *mcctrl_get_per_thread_data(struct mcctrl_per_proc_data *ppd, struct task_struct *task);
#endif /* POSTK_DEBUG_ARCH_DEP_56 */
void __return_syscall(ihk_os_t os, struct ikc_scd_packet *packet,