Linux Strace tool user guide

Transcription

1 Linux Strace tool user guide

2 Reversion Record Date Rev Change Description Author V0.1 Initial Zhang Yongchang 1 / 9

3 catalog 1 PURPOSE TERMINOLOGY ENVIRONMENT HARDWARE PLATFORM SOFTWARE PLATFORM INSTALL GUIDE DOWNLOAD THE STRACE ENVIRONMENT PREPARED COMPILE STRACE USE GUIDE SIMPLE EXAMPLE Trace system call Trace signal STATISTICAL SYSTEM CALL OTHER OPTIONS DESCRIPTION TRACE A EXIST PROCESS / 9

4 Figure index Figure 1 trace system call...6 Figure 2 trace signal (1)...7 Figure 3 trace signal (2)...8 Figure 4 statistical system call / 9

5 1 Purpose This guide help user install the strace on ARM, and show how to use Strace to intercept and record the system calls. 2 Terminology strace: strace is a diagnostic, debugging and instructional user space utility for Linux. It is used to monitor and tamper with interactions between processes and the Linux kernel, which include system calls, signal deliveries, and changes of process state. The operation of strace is made possible by the kernel feature known as ptrace. 3 Environment 3.1 Hardware Platform SOC: Rockchip RK3399 GPU: Mali T864 (800MHz) CPU: Dual-core Cortex-A72 up to 2.0GHz (real frequency is 1.8GHz) Quad-core Cortex-A53 up to 1.5GHz (real frequency is 1.4GHz) 3.2 Software Platform OS: Ubuntu (32bit) 4 Install Guide 4.1 Download the strace wget tar -xvf strace-4.19.tar.xz cd ~/ mkdir -p build-starce To assume the code directory: strace source code:~/strace-4.19 strace build:~/build-strace 4 / 9

6 4.2 Environment Prepared sudo apt-get install flex bison libelf-dev libaudit-dev libdw-dev libunwind-dev python-dev sudo apt-get install libnuma-dev libunwind8 libunwind8-dev sudo apt-get install libslang2 libslang2-dev sudo apt-get install binutils-multiarch-dev elfutils libiberty-dev sudo apt-get install gcc-arm-linux-gnueabihf 4.3 Compile Strace cd ~/build-strace CC=arm-linux-gnueabihf-gcc LD=arm-linux-gnueabifh-ld RANLIB=arm-linux-gnueabihf-ranlib../strace- 4.19/configure --host=arm-linux --target=arm-linux --prefix=/usr/ make j4 sudo make install If your system is 64bit, you should specific --target=aarch64-linux, --host=aarch64-linux. 5 Use Guide 5.1 Simple example Create a test file test.c: #include <stdio.h> int main() { } int num = 0; printf( Please input number: ); scanf( %d, &num); printf( %09d\n, num); return 0; Compile test: 5 / 9

7 gcc o test test.c Trace system call From the output we can know: Figure 1 trace system call 1. The system calls the exec to start a new process, then to prepare the environment. 2. Pause at "read (0,", and wait for input the number. 6 / 9

8 3. Input the number 99, the writer function output \n to the screen. 4. Call exit_group() to complete the entire process Trace signal Figure 2 trace signal (1) Now, we don t input anything, it block at the read function. Start a new terminal: killall test And you can see the strace output: 7 / 9

9 Figure 3 trace signal (2) The test process receives the SIFTERM signal, it will be terminated. 5.2 Statistical system call Strace can count times, calls and errors for the system call, and report a summary. 5.3 Other Options description Please read Strace command manual Figure 4 statistical system call man strace 5.4 Trace a exist process Attach to the process with the process ID pid and begin tracing. The trace may be terminated at any time by a keyboard interrupt signal (CTRL-C). Strace will respond by detaching itself from the traced process(es) leaving it (them) to continue running. Multiple -p options can be used to attach to many processes in addition to command (which is optional if at least one -p option is given). -p "`pidof PROG`" syntax is supported. 8 / 9

10 strace p pid 9 / 9