strace工具简介及使用

一．Strace简介

用户态的Strace工具跟踪进程的系统调用，注意是只能跟踪系统调用，不能跟踪用户程序和库

 

内核也自带一个strace调试工具，内核的这个strace跟踪内核函数调用过程，与这个strace有区别。

 

二．Strace编译

以编译t1020的strace工具为例子

（1）下载源码，进入源码目录，运行configure进行配置

. ./configure

--prefix=/home/workspace/hbx/strace/strace-4.5.14

--host=powerpc-linux

--target=powerpc-linux

CC=/opt/ppc8540_gcc4.1.2_glibc2.5.0/bin/powerpc-8540-linux-gnu-gcc LD=/opt/ppc8540_gcc4.1.2_glibc2.5.0/bin/powerpc-8540-linux-gnu-ld 

RANLIB=/opt/ ppc8540_gcc4.1.2_glibc2.5.0/bin/powerpc-8540-linux-gnu-ranlib

 

（2）静态编译

make CFLAGS+="-static"

 

（3）make install

 

静态编译的strace工具如下，下载到板子上即可运行调试

 

三．Strace 用法

1.Strace –p  (进程pid)

显示进程系统调用

 

2.Strace –tt –p (进程pid)

显示进程系统调用，带时间

 

3.Strace系统调用统计：

# strace -c -p 3975

Process 3975 attached

^CProcess 3975 detached

% time     seconds  usecs/call     calls    errors syscall

------ ----------- ----------- --------- --------- ----------------

 42.13    0.108059          43      2530      1241 open

 23.54    0.060374          45      1335           read

 17.05    0.043741          35      1241           stat

 11.09    0.028432          20      1420           close

  2.90    0.007426          28       262           getdents

  2.21    0.005660          43       131           openat

  0.89    0.002284          48        48           write

  0.07    0.000174          58         3           munmap

  0.04    0.000103         103         1           brk

  0.04    0.000097          97         1           poll

  0.03    0.000072          24         3           mmap

  0.01    0.000036          12         3           fstat

  0.01    0.000015          15         1           ioctl

------ ----------- ----------- --------- --------- ----------------

100.00    0.256473                  6979      1241 total

#

 

4.加-T,统计系统调用耗时

# strace -T -p 3975

Process 3975 attached

restart_syscall(<... resuming interrupted call ...>) = 0 <2.157076> //方括号内即调用耗时

ioctl(1, _IOC(_IOC_READ, 0x74, 0x68, 0x08), {ws_row=48, ws_col=177, ws_xpixel=0, ws_ypixel=0}) = 0 <0.000030>

openat(AT_FDCWD, "/proc", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 3 <0.000062>

getdents(3, /* 226 entries */, 32768)   = 5864 <0.001486>

stat("/proc/1", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0 <0.000054>

open("/proc/1/intr", O_RDONLY)          = -1 ENOENT (No such file or directory) <0.000060>

open("/proc/1/stat", O_RDONLY)          = 4 <0.000237>

read(4, "1 (init) S 0 1 1 0 -1 4194560 22"..., 1023) = 302 <0.000063>

close(4)                                = 0 <0.000037>

openat(AT_FDCWD, "/proc/1/task", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 4 <0.000055>

getdents(4, /* 3 entries */, 32768)     = 72 <0.000034>

stat("/proc/1/task/1", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0 <0.000104>

open("/proc/1/task/1/intr", O_RDONLY)   = -1 ENOENT (No such file or directory) <0.000058>

open("/proc/1/task/1/stat", O_RDONLY)   = 5 <0.000102>

read(5, "1 (init) S 0 1 1 0 -1 4194560 22"..., 1023) = 302 <0.000085>