157 lines
4.3 KiB
Diff
157 lines
4.3 KiB
Diff
From ebb60a10ac3c6b28ba7a46aa67b279d41ad9356d Mon Sep 17 00:00:00 2001
|
|
From: Elizabeth Figura <zfigura@codeweavers.com>
|
|
Date: Fri, 13 Dec 2024 13:34:48 -0600
|
|
Subject: ntsync: Introduce NTSYNC_IOC_MUTEX_KILL.
|
|
|
|
This does not correspond to any NT syscall. Rather, when a thread dies, it
|
|
should be called by the NT emulator for each mutex, with the TID of the dying
|
|
thread.
|
|
|
|
NT mutexes are robust (in the pthread sense). When an NT thread dies, any
|
|
mutexes it owned are immediately released. Acquisition of those mutexes by other
|
|
threads will return a special value indicating that the mutex was abandoned,
|
|
like EOWNERDEAD returned from pthread_mutex_lock(), and EOWNERDEAD is indeed
|
|
used here for that purpose.
|
|
|
|
Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com>
|
|
---
|
|
drivers/misc/ntsync.c | 61 +++++++++++++++++++++++++++++++++++--
|
|
include/uapi/linux/ntsync.h | 1 +
|
|
2 files changed, 60 insertions(+), 2 deletions(-)
|
|
|
|
--- a/drivers/misc/ntsync.c
|
|
+++ b/drivers/misc/ntsync.c
|
|
@@ -59,6 +59,7 @@ struct ntsync_obj {
|
|
struct {
|
|
__u32 count;
|
|
pid_t owner;
|
|
+ bool ownerdead;
|
|
} mutex;
|
|
} u;
|
|
|
|
@@ -107,6 +108,7 @@ struct ntsync_q {
|
|
atomic_t signaled;
|
|
|
|
bool all;
|
|
+ bool ownerdead;
|
|
__u32 count;
|
|
struct ntsync_q_entry entries[];
|
|
};
|
|
@@ -275,6 +277,9 @@ static void try_wake_all(struct ntsync_d
|
|
obj->u.sem.count--;
|
|
break;
|
|
case NTSYNC_TYPE_MUTEX:
|
|
+ if (obj->u.mutex.ownerdead)
|
|
+ q->ownerdead = true;
|
|
+ obj->u.mutex.ownerdead = false;
|
|
obj->u.mutex.count++;
|
|
obj->u.mutex.owner = q->owner;
|
|
break;
|
|
@@ -338,6 +343,9 @@ static void try_wake_any_mutex(struct nt
|
|
continue;
|
|
|
|
if (atomic_try_cmpxchg(&q->signaled, &signaled, entry->index)) {
|
|
+ if (mutex->u.mutex.ownerdead)
|
|
+ q->ownerdead = true;
|
|
+ mutex->u.mutex.ownerdead = false;
|
|
mutex->u.mutex.count++;
|
|
mutex->u.mutex.owner = q->owner;
|
|
wake_up_process(q->task);
|
|
@@ -447,6 +455,52 @@ static int ntsync_mutex_unlock(struct nt
|
|
return ret;
|
|
}
|
|
|
|
+/*
|
|
+ * Actually change the mutex state to mark its owner as dead,
|
|
+ * returning -EPERM if not the owner.
|
|
+ */
|
|
+static int kill_mutex_state(struct ntsync_obj *mutex, __u32 owner)
|
|
+{
|
|
+ ntsync_assert_held(mutex);
|
|
+
|
|
+ if (mutex->u.mutex.owner != owner)
|
|
+ return -EPERM;
|
|
+
|
|
+ mutex->u.mutex.ownerdead = true;
|
|
+ mutex->u.mutex.owner = 0;
|
|
+ mutex->u.mutex.count = 0;
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+static int ntsync_mutex_kill(struct ntsync_obj *mutex, void __user *argp)
|
|
+{
|
|
+ struct ntsync_device *dev = mutex->dev;
|
|
+ __u32 owner;
|
|
+ bool all;
|
|
+ int ret;
|
|
+
|
|
+ if (get_user(owner, (__u32 __user *)argp))
|
|
+ return -EFAULT;
|
|
+ if (!owner)
|
|
+ return -EINVAL;
|
|
+
|
|
+ if (mutex->type != NTSYNC_TYPE_MUTEX)
|
|
+ return -EINVAL;
|
|
+
|
|
+ all = ntsync_lock_obj(dev, mutex);
|
|
+
|
|
+ ret = kill_mutex_state(mutex, owner);
|
|
+ if (!ret) {
|
|
+ if (all)
|
|
+ try_wake_all_obj(dev, mutex);
|
|
+ try_wake_any_mutex(mutex);
|
|
+ }
|
|
+
|
|
+ ntsync_unlock_obj(dev, mutex, all);
|
|
+
|
|
+ return ret;
|
|
+}
|
|
+
|
|
static int ntsync_obj_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct ntsync_obj *obj = file->private_data;
|
|
@@ -468,6 +522,8 @@ static long ntsync_obj_ioctl(struct file
|
|
return ntsync_sem_release(obj, argp);
|
|
case NTSYNC_IOC_MUTEX_UNLOCK:
|
|
return ntsync_mutex_unlock(obj, argp);
|
|
+ case NTSYNC_IOC_MUTEX_KILL:
|
|
+ return ntsync_mutex_kill(obj, argp);
|
|
default:
|
|
return -ENOIOCTLCMD;
|
|
}
|
|
@@ -652,6 +708,7 @@ static int setup_wait(struct ntsync_devi
|
|
q->owner = args->owner;
|
|
atomic_set(&q->signaled, -1);
|
|
q->all = all;
|
|
+ q->ownerdead = false;
|
|
q->count = count;
|
|
|
|
for (i = 0; i < count; i++) {
|
|
@@ -760,7 +817,7 @@ static int ntsync_wait_any(struct ntsync
|
|
struct ntsync_wait_args __user *user_args = argp;
|
|
|
|
/* even if we caught a signal, we need to communicate success */
|
|
- ret = 0;
|
|
+ ret = q->ownerdead ? -EOWNERDEAD : 0;
|
|
|
|
if (put_user(signaled, &user_args->index))
|
|
ret = -EFAULT;
|
|
@@ -841,7 +898,7 @@ static int ntsync_wait_all(struct ntsync
|
|
struct ntsync_wait_args __user *user_args = argp;
|
|
|
|
/* even if we caught a signal, we need to communicate success */
|
|
- ret = 0;
|
|
+ ret = q->ownerdead ? -EOWNERDEAD : 0;
|
|
|
|
if (put_user(signaled, &user_args->index))
|
|
ret = -EFAULT;
|
|
--- a/include/uapi/linux/ntsync.h
|
|
+++ b/include/uapi/linux/ntsync.h
|
|
@@ -41,5 +41,6 @@ struct ntsync_wait_args {
|
|
|
|
#define NTSYNC_IOC_SEM_RELEASE _IOWR('N', 0x81, __u32)
|
|
#define NTSYNC_IOC_MUTEX_UNLOCK _IOWR('N', 0x85, struct ntsync_mutex_args)
|
|
+#define NTSYNC_IOC_MUTEX_KILL _IOW ('N', 0x86, __u32)
|
|
|
|
#endif
|