1.modifications:
modified:   syscall/los_syscall.h
modified:   syscall/misc_syscall.c
modified:   syscall/syscall_lookup.h
2.add 3 testcases:
testsuites/unittest/IO/full/IO_test_ppoll_001.cpp
testsuites/unittest/IO/full/IO_test_ppoll_002.cpp
3.influence:
none
Signed-off-by: Nteamol <28105285@qq.com>

Merge pull request !504 from phchang/updateclock

Merge pull request !567 from Caoruihong/opt_make

Signed-off-by: NCaoruihong <crh.cao@huawei.com>
Change-Id: I2e61b7ea231be78423dc10412e0ab9a710cad8ef

Merge pull request !564 from Caoruihong/update_makefile

Signed-off-by: NCaoruihong <crh.cao@huawei.com>
Change-Id: Ie2dfa7334417ccd55bd56a19a7882a982ce49cab

Merge pull request !563 from wangchen/a_codex

【背景】定期A核代码消除。

【修改方案】
1，根据工具扫描结果，对代码告警进行更改

【影响】
对现有的产品编译不会有影响。

re #I46KF6
Signed-off-by: Nwangchen <253227059@qq.com>

Merge pull request !487 from JerryH/smp-xxx

Merge pull request !558 from Caoruihong/update_musl

Merge pull request !558 from Caoruihong/update_musl

Signed-off-by: NCaoruihong <crh.cao@huawei.com>
Change-Id: I32b820bc0eb7465bf54d506e7f5e759ef64101e2

Merge pull request !538 from 野生毛霉君/master

Merge pull request !557 from susha/master

Merge pull request !556 from Caoruihong/update_makefile

remove some unused Makefile code and optimize some code
Signed-off-by: NCaoruihong <crh.cao@huawei.com>
Change-Id: I1c31d07481bb6aee47b0c51d63d6b68316c38c88

Signed-off-by: Nsusha <susha@huawei.com>

close: #I44WH1
Signed-off-by: Nmucor <mucorwang@gmail.com>

Merge pull request !548 from zhushengle/sched_time

初始化调度时间不以g_sysSchedStartTime是否为0为界限，而以g_sysSchedStartTime是否为64位最大值
为界限，避免特殊以下场景：调度开启时系统时间为0，导致初始化的g_sysSchedStartTime还是0，导致
调度启动后获取的调度时间轴始终为0.
Close  #I45HP5
Signed-off-by: Nzhushengle <zhushengle@huawei.com>
Change-Id: I5272c79f06b53361ee7b931081d3a3276db59073

【背景】当前kernel的unittest下的用例全量与门禁用例结构不合理，当前上传clock修改后版本

【修改方案】
1 原来没有测试clock模块的基本场景，这里补上基本场景作为smoke用例，并命名为clock_test_smoke.cpp
2 将原来smoke用例移到full中
3 删除与xts测试重复的用例和标记宏TEST_ON_LINUX的用例（即原来版本的clock_test_002,003,004用例）
4 原来clock_test_012用例用于测试进程的运行时间，里面存在正常场景和异常场景，现在将其分成两个用例
5 对所有用例重新排序，使得结构完整

re #I44170
Signed-off-by: Nvcbchang <vcbchang@qq.com>

Change-Id: I30852a5f9c414668c00eddbcc9631d70818514a1

Merge pull request !541 from Kiita/shell_cmd_0812

Merge pull request !495 from lnlan/fix_mqueue_0803

Merge pull request !521 from phchang/fixsync_8

Merge pull request !521 from phchang/fixsync_8

【背景】liteos_a需要支持toybox缺失的自研shell命令

【修改方案】
新增自研shell命令的入口判断场景，使得mksh可以执行自研shell的命令

re #I44U0H
Signed-off-by: yansira <yansira@hotmail.com>
Change-Id: Idf08cb6df456bd6c89fe8fe505317f1c0ca61eda

Merge pull request !542 from Harylee/qemu

close #I45297
Signed-off-by: NHaryslee <lihao189@huawei.com>
Change-Id: Ide31fc41af0ecc72c2b7fbaed85efe9b6530467b

Merge pull request !539 from wcc/fchmod0

Merge pull request !287 from MGY917/master

Merge pull request !287 from MGY917/master

Merge pull request !536 from Caoruihong/liteos_a_mini

Merge pull request !536 from Caoruihong/liteos_a_mini

Merge pull request !527 from Harylee/dyn

首先，POSIX规范规定文件描述符需要支持close-on-exec属性，修改前的vfs不支持close-on-exec，当exec系列函数执行时，进程所有的文件将会被关闭（0，1，2也重新被打开）。但是，系统有些时候是不能在exec时关闭全部文件的，例如在执行exec之前，就需要重定向进程的某些文件描述符时（使用dup2），就希望该文件不被关闭，继续保持重定向属性，shell执行进程并重定向其标准输出到文件，这是我们经常做的事情。

BREAKING CHANGE:
执行exec类函数后，进程拥有的文件描述符情况发生变化：修改前，默认关闭所有的进程文件描述符，0，1，2重新打开；修改后，除非文件描述符拥有FD_CLOEXEC标记，否则该描述符不会被关闭。

re #I3U81W

Change-Id: I54e841ac88e9835ec23e97de0cbc906c4e11f5a4
Signed-off-by: NGuangyao Ma <guangyao.ma@outlook.com>

Merge pull request !502 from Zhaotianyu/0731libc_opt

add fchmod api and testcases

Change-Id: I310e9e9d79bbe3fa8dbab6080bbfce8a77b79bb3
Signed-off-by: Nwcc0 <917033401@qq.com>

Merge pull request !477 from wcc/fstatfs

!388 fix mutex&pthread mould musl api:pthread_mutexattr_getrobust/pthread_mutexattr_setrobust/pthread_mutex_consistent/pthread_getconcurrency/pthread_setconcurrency
Merge pull request !388 from 王建军/mutex

Merge pull request !518 from zhushengle/sched_tick