This PR is a modification that optimizes priority inheritance
for only one holder. After the above modifications are completed,
the mutex lock->unlock process that supports priority inheritance
can be optimized by 200 cycles.
Before modify: 2000 cycle
After modify: 1742 cycle
Signed-off-by: zhangyuan21 <zhangyuan21@xiaomi.com>
In many cases, it is legal for the child process to use the fd
created by the parent process,
so to improve compatibility, we allow the child process
to use the fd of the Parent process.
Signed-off-by: hujun5 <hujun5@xiaomi.com>
use PTHREAD_CLEANUP_STACKSIZE to enable or disable interfaces pthread_cleanup_push() and pthread_cleanup_pop().
reasons:(1)same as TLS_TASK_NELEM (2)it is no need to use two variables
Signed-off-by: yanghuatao <yanghuatao@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>
in the initial impl, the regex is depends on ALLOW_MIT_COMPONENTS, and
if other modules want to use regex, also needs to depends on
ALLOW_MIT_COMPONENTS, which is ambiguity, so we provide a seperate
kconfig option for regex: LIBC_REGEX, which is depends on
ALLOW_MIT_COMPONENTS, but is enabled by default. Thus if
ALLOW_MIT_COMPONENTS is enabled, then the LIBC_REGEX is also enabled
either automatically, and this is more clear than controlled by
ALLOW_MIT_COMPONENTS option only.
Signed-off-by: guoshichao <guoshichao@xiaomi.com>
- Linux: What inside /etc/hosts comes first.
- NuttX: Even if we write a domain in /etc/hosts, we still use DNS
result instead of hosts lines. This patch change this behavior.
Signed-off-by: Zhe Weng <wengzhe@xiaomi.com>
Add the `LIBC_PREVENT_STRING_KERNEL` and `LIBC_PREVENT_STRING_USER`
that are meant to be selected by the chip if no libc implementation
is going to be built. If selected, neither NuttX's software version
of the libc nor any architecture-specific implementation will be
built in the kernel or in the userspace, respectively. In this
case, the linker may provide a ROM-defined version of the libc
functions instead.
FD (file descriptor) is widely used in system software development,
and almost all implementations of posix os (including nuttx) use FD as an index.
the value of fd needs to be allocated starting from the minimum available value of 3, and each process has a copy,
so the same fd value is very easy to reuse in the program.
In multi threaded or multi process environments without address isolation,
If the ownership, global variables, and competition relationships of fd are not properly handled,
there may be issues with fd duplication or accidental closure.
Further leading to the following issues, which are difficult to troubleshoot.
1. Security vulnerability: the fd we wrote is not the expected fd and will be accessed by hackers to obtain data
2. Program exceptions or crashes: write or read fd failures, and program logic errors
3. The structured file XML or database is damaged: the data format written to the database is not the expected format.
The implementation principle of fdsan is based on the implementation of Android
https://android.googlesource.com/platform/bionic/+/master/docs/fdsan.md
Signed-off-by: hujun5 <hujun5@xiaomi.com>
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_setcancelstate.html
The pthread_setcancelstate() function may fail if:
[EINVAL]
The specified state is not PTHREAD_CANCEL_ENABLE or PTHREAD_CANCEL_DISABLE.
The pthread_setcanceltype() function may fail if:
[EINVAL]
The specified type is not PTHREAD_CANCEL_DEFERRED or PTHREAD_CANCEL_ASYNCHRONOUS.
Signed-off-by: zhangyuan21 <zhangyuan21@xiaomi.com>
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_once.html
If an implementation detects that the value specified by the once_control
argument to pthread_once() does not refer to a pthread_once_t object
initialized by PTHREAD_ONCE_INIT, it is recommended that the function
should fail and report an [EINVAL] error.
Signed-off-by: zhangyuan21 <zhangyuan21@xiaomi.com>
