If cancellation points are enabled, then the following logic is activated in sem_wait(). This causes ECANCELED to be returned every time that sem_wait is called.
int sem_wait(FAR sem_t *sem)
{
...
/* sem_wait() is a cancellation point */
if (enter_cancellation_point())
{
#ifdef CONFIG_CANCELLATION_POINTS
/* If there is a pending cancellation, then do not perform
* the wait. Exit now with ECANCELED.
*/
errcode = ECANCELED;
goto errout_with_cancelpt;
#endif
}
...
Normally this works fine. sem_wait() is the OS API called by the application and will cancel the thread just before it returns to the application. Since it is cancellation point, it should never be called from within the OS.
There there is is one perverse cases where sem_wait() may be nested within another cancellation point. If open() is called, it will attempt to lock a VFS data structure and will eventually call nxmutex_lock(). nxmutex_lock() waits on a semaphore:
int nxmutex_lock(FAR mutex_t *mutex)
{
...
for (; ; )
{
/* Take the semaphore (perhaps waiting) */
ret = _SEM_WAIT(&mutex->sem);
if (ret >= 0)
{
mutex->holder = _SCHED_GETTID();
break;
}
ret = _SEM_ERRVAL(ret);
if (ret != -EINTR && ret != -ECANCELED)
{
break;
}
}
...
}
In the FLAT build, _SEM_WAIT expands to sem_wait(). That causes the error in the logic: It should always expand to nxsem_wait(). That is because sem_wait() is cancellation point and should never be called from with the OS or the C library internally.
The failure occurs because the cancellation point logic in sem_wait() returns -ECANCELED (via _SEM_ERRVAL) because sem_wait() is nested; it needs to return the -ECANCELED error to the outermost cancellation point which is open() in this case. Returning -ECANCELED then causes an infinite loop to occur in nxmutex_lock().
The correct behavior in this case is to call nxsem_wait() instead of sem_wait(). nxsem_wait() is identical to sem_wait() except that it is not a cancelation point. It will return -ECANCELED if the thread is canceled, but only once. So no infinite loop results.
In addition, an nxsem_wait() system call was added to support the call from nxmutex_lock().
This resolves Issue #9695
This function will use gcc's function
__builtin_dynamic_object_size and __builtin_object_size
Its function is to obtain the size of the object through compilation,
so as to judge whether there are out-of-bounds operations in commonly used functions.
It should be noted that the option -O2 and above is required to enable this function
Signed-off-by: anjiahao <1090959677@qq.com>
because NuttX doesn't have the device number, so we're not assigning a
valid value here. just memset to zero.
Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>
In embedded development environments, due to the lack of address isolation between processes,
fd may be passed between processes and lead to misuse,
We have designed an fd cross-process automatic detection tool,
fdcheck_protect returns the fd containing the pid information,
indicating that the ownership of the current fd belongs to the pid and is not allowed to be used by other processes.
fdcheck_restore will obtain the true fd and check if the ownership of the fd is legal
For ease of understanding, let's give an example where
the following information is represented in 32-bit binary format
fd 00000000 00000000 00000000 10001010
pid 00000000 00000000 00000011 01010101
ret 00000000 00000011 01010101 10001010
Signed-off-by: hujun5 <hujun5@xiaomi.com>
Updated alt1250 driver with regarding to the following changes.
- Add LTE hibernation feature
- Split source code per module
- Some refactoring
- Some bug fixes
RESTORE_FACTORY used to reset the device
FACTORY_INQUIRY used to reset the device but need user confirmed.
Signed-off-by: minjian.tang <minjian.tang@aqara.com>
CURRENT_REGS may change during assert handling, so pass
in the 'regs' parameter at the entry point of _assert.
Signed-off-by: zhangyuan21 <zhangyuan21@xiaomi.com>
This commit adds Linux like adjtime() interface that is used to correct
the system time clock if it varies from real value. The adjustment is
done by slight adjustment of clock period and therefore the adjustment
is without time jumps (both forward and backwards)
The implementation is enabled by CONFIG_CLOCK_ADJTIME and separated from
CONFIG_CLOCK_TIMEKEEPING functions. Options CONFIG_CLOCK_ADJTIME_SLEWLIMIT
and CONFIG_CLOCK_ADJTIME_PERIOD can be used to control the adjustment
speed.
Interfaces up_get_timer_period() and up_adj_timer_period() has to be
defined by architecture level support.
This is not a POSIX interface but derives from 4.3BSD, System V.
It is also supported for Linux compatibility.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>
The current implementation requires the use of enter_critical_section, so the source code needs to be moved to kernel space
Signed-off-by: hujun5 <hujun5@xiaomi.com>
SOCK_CTRL is added to provide special control over network drivers
and daemons. Currently, SOCK_DGRAM and SOCK_STREAM perform this control,
but these use socket resources. In the case of usersocket in particular,
this is a waste of the device's limited socket resources.
The version information basically uses 20 characters for date and time,
which is small enough to specify an arbitrary version string. Therefore,
increase the buffer a little.
SOCK_CTRL is added to provide special control over network drivers
and daemons. Currently, SOCK_DGRAM and SOCK_STREAM perform this control,
but these use socket resources. In the case of usersocket in particular,
this is a waste of the device's limited socket resources.
First configure nuttx to support ipv4 and ipv6 dual stack,
then start two simulators and run Iperf ipv4 udp speed test,
unaligned access exception to sockaddr_in occours.
The root cause is that struct sockaddr_storage isn't set to
the desired alignment.
Signed-off-by: luojun1 <luojun1@xiaomi.com>
dbus/dbus/dbus-pollable-set-epoll.c:258:18: error: ‘EPOLLET’ undeclared
(first use in this function); did you mean ‘EPOLLERR’?
258 | event.events = EPOLLET;
| ^~~~~~~
| EPOLLERR
Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>
