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>
The spawn proxy thread is a special existence in NuttX, usually some developers
spend a lot of time on stack overflow of spawn proxy thread:
https://github.com/apache/nuttx/issues/9046https://github.com/apache/nuttx/pull/9081
In order to avoid similar issues, this PR will remove spawn proxy thread to simplify
the process of task/posix_spawn().
1. Postpone the related processing of spawn file actions until after task_init()
2. Delete the temporary thread of spawn proxy and related global variables
Signed-off-by: chao an <anchao@xiaomi.com>
fix the problem that stat fails to use the relative path
An error will be reported if used in the following way:
stat("//./bin", &st);
Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>
and remove the check of SYS_DOWN since it defines to SYS_RESTART in reboot_notifer.h:
#define SYS_DOWN 0x0001 /* Notify of system down */
#define SYS_RESTART SYS_DOWN
#define SYS_HALT 0x0002 /* Notify of system halt */
#define SYS_POWER_OFF 0x0003 /* Notify of system power off */
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
This way the mappings can be modified for any vm area, not only the
process that is running.
Why? This allows mapping pages to kernel dynamically, this functionality
will be presented later.
Refer to issue #8867 for details and rational.
Convert sigset_t to an array type so that more than 32 signals can be supported.
Why not use a uin64_t?
- Using a uin32_t is more flexible if we decide to increase the number of signals beyound 64.
- 64-bit accesses are not atomic, at least not on 32-bit ARMv7-M and similar
- Keeping the base type as uint32_t does not introduce additional overhead due to padding to achieve 64-bit alignment of uin64_t
- Some architectures still supported by NuttX do not support uin64_t
types,
Increased the number of signals to 64. This matches Linux. This will support all xsignals defined by Linux and also 32 real time signals (also like Linux).
This is is a work in progress; a draft PR that you are encouraged to comment on.
In the last change, the assert behavior test was not considered. Therefore, in this change, sync will be performed only when SYS_RESTART/SYS_DOWN situation occurs, avoiding unpredictable results caused by handling locks or semaphores in interrupts.
mount/fs_foreachmountpoint.c: In function 'mountpoint_filter':
mount/fs_foreachmountpoint.c:99:38: warning: 'sprintf' may write a terminating nul past the end of the destination [-Wformat-overflow=]
99 | sprintf(&dirpath[pathlen], "/%s", node->i_name);
| ^
In function 'mountpoint_filter',
inlined from 'mountpoint_filter' at mount/fs_foreachmountpoint.c:64:12:
mount/fs_foreachmountpoint.c:99:7: note: 'sprintf' output between 2 and 257 bytes into a destination of size 256
99 | sprintf(&dirpath[pathlen], "/%s", node->i_name);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: chao an <anchao@xiaomi.com>
