1.【需求描述】
            L0~L1 支持Trace，提供两种工作模式：在线模式、离线缓存模式， 用于按时间线追踪系统事件，如任务切换、中断、ipc等。
        2.【方案描述】
            L0:
            (1).在内核模块预置静态代码桩
            (2).触发桩后，收集系统上下文信息
            (3).离线模式则写入内存，用户可通过dump导出；
            (4).在线模式通过pipeline对接IDE进行可视化解析和展示；
            L1:
            新增trace字符设备，位于"/dev/trace",通过对设备节点的read\write\ioctl，实现用户态trace；

        BREAKING CHANGE:
        1.新增一系列trace的对外API，位于los_trace.h中.
        LOS_TRACE_EASY简易插桩
        LOS_TRACE标准插桩
        LOS_TraceInit配置Trace缓冲区的地址和大小
        LOS_TraceStart开启事件记录
        LOS_TraceStop停止事件记录
        LOS_TraceRecordDump输出Trace缓冲区数据
        LOS_TraceRecordGet获取Trace缓冲区的首地址
        LOS_TraceReset清除Trace缓冲区中的事件
        LOS_TraceEventMaskSet设置事件掩码，仅记录某些模块的事件
        LOS_TraceHwiFilterHookReg注册过滤特定中断号事件的钩子函数

        Close #I46WA0
Signed-off-by: NLiteOS2021 <dinglu@huawei.com>

Change-Id: I6a8e64794c4852f2c2980993a06180e09ec6ee0d

Merge pull request !586 from jason_gitee/master

Merge pull request !588 from 马帅/master

Merge pull request !590 from Caoruihong/lto

Signed-off-by: NCaoruihong <crh.cao@huawei.com>
Change-Id: Ibf8df58696b7f1ccb3b5b21154c3b94dda1e8ad2

Merge pull request !579 from Caoruihong/optimize_build_scripts

Signed-off-by: NCaoruihong <crh.cao@huawei.com>
Change-Id: Ibb4223ef2d032a03950263b766414ca1c021e69a

Merge pull request !570 from guweijie/gwj-kernel-ppoll-20210825

Signed-off-by: Njason_gitee <yangjie140@huawei.com>

Signed-off-by: Nmaltose214 <mashuai3@huawei.com>

Merge pull request !573 from Caoruihong/v21.02

Merge pull request !571 from wangjianjun/sys

Merge pull request !561 from guweijie/gwj-kernel-20210819

Merge pull request !544 from wangjianjun/waitid

Merge pull request !543 from wcc/fs

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>

Signed-off-by: NCaoruihong <crh.cao@huawei.com>
Change-Id: I5cdca0ee82d3e8a164120fe3ecb6e94f2f89d600

把测试用例放在full中，需要依赖文件group和passwd，放在/etc下

Change-Id: Ie038b64db96180b52ee10d70d494da42207d3b92
Signed-off-by: Nwjj <502004968@qq.com>

Merge pull request !569 from Caoruihong/mksh_toybox

Signed-off-by: NCaoruihong <crh.cao@huawei.com>
Change-Id: Ie152b0ad21af5dc8e8c31c71f236500e5726e1c4

add fchdir and testcases

Change-Id: Iad724944e727c4a08b8801f109acbbe48f55c283
Signed-off-by: Nwcc0 <917033401@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

1.modifications:
modified:   testsuites/unittest/fs/BUILD.gn
modified:   testsuites/unittest/fs/jffs/It_vfs_jffs.h
renamed:    testsuites/unittest/fs/jffs/smoke/It_test_faccessat_001.cpp -> testsuites/unittest/fs/jffs/full/It_test_faccessat_001.cpp
renamed:    testsuites/unittest/fs/jffs/smoke/It_test_faccessat_002.cpp -> testsuites/unittest/fs/jffs/full/It_test_faccessat_002.cpp
renamed:    testsuites/unittest/fs/jffs/smoke/It_test_fstatat_001.cpp -> testsuites/unittest/fs/jffs/full/It_test_fstatat_001.cpp
renamed:    testsuites/unittest/fs/jffs/smoke/It_test_fstatat_002.cpp -> testsuites/unittest/fs/jffs/full/It_test_fstatat_002.cpp
renamed:    testsuites/unittest/fs/jffs/smoke/It_test_fstatfs_001.cpp -> testsuites/unittest/fs/jffs/full/It_test_fstatfs_001.cpp
renamed:    testsuites/unittest/fs/jffs/smoke/It_test_fstatfs_002.cpp -> testsuites/unittest/fs/jffs/full/It_test_fstatfs_002.cpp
modified:   testsuites/unittest/fs/jffs/vfs_jffs_test.cpp
2.add 6 testcases:
It_test_faccessat_001.cpp
It_test_faccessat_002.cpp
It_test_fstatat_001.cpp
It_test_fstatat_002.cpp
It_test_fstatfs_001.cpp
It_test_fstatfs_002.cpp
3.influence:
none
Signed-off-by: Nteamol <28105285@qq.com>

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