# ubuntu 18+
> apt-get update
> apt-get install -y gcc git make
> git pull https://github.com/SirHao/MemCapture
test1/main.c
is a demo of user's application, use
$test1: gcc -o main main.c
to complie. Then, use following command to run this demo:
$test1: ./main
$out> a b c d e f g h i
a b c d e f g h i
a b c d e f g h i
test2/
is our main workspace to capture user-application systemcall on malloc(2)
and free(1)
The Makefile is already done, use
$test2: make
to update the Mem.so for every modification
- note: since
printf(...)
also usemalloc(2)
to alloc a buffer, in mem.c, usefprintf(stderr,xxx)
intead ofprintf
. Otherwise, core dump occures.
in the terminal used to run test1/main
, before run, type:
export LD_PRELOAD=/home/xx/test2xxx/Mem.so # notice: use absolute path of Mem.so
this will load Mem.so into this terminal . From now on, all following processes in this terminal will firstly call our func with the same name (now, we only capture to systemcall malloc
and ``).
Then:
./main
you will find there are something diff. from before, the user application will firstly enter our mem.c:malloc(2)
, print sth. , then call the real malloc(2)
in our logic., the out put is:
[malloc] request:10
[malloc] request:1024
a b c d e f g h i
[free] free
[malloc] request:10
a b c d e f g h i
[free] free
[malloc] request:10
a b c d e f g h i
[free] free