jrelo

obj-m += test_module.o

all:
	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules

clean:
	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

jrelo

#!/bin/bash
echo -e "\e[34m青い \e[31m赤い \e[32m緑 \e[93m黄色い \e[35m紫 \e[95mピンク \e[30m黒い \e[97m白い \e[33mオレンギ"

jrelo

#!/bin/bash
set -e

# Usage:
#   rsync_parallel.sh [--parallel=N] [rsync args...]
# 
# Options:
#   --parallel=N	Use N parallel processes for transfer. Defaults to 10.
#
# Notes:

jrelo

Sysvinit Command	Systemd Command	Notes
service frobozz start	systemctl start frobozz	Used to start a service (not reboot persistent)
service frobozz stop	systemctl stop frobozz	Used to stop a service (not reboot persistent)
service frobozz restart	systemctl restart frobozz	Used to stop and then start a service
service frobozz reload	systemctl reload frobozz	When supported, reloads the config file without interrupting pending operations.
service frobozz condrestart	systemctl condrestart frobozz	Restarts if the service is already running.
service frobozz status	systemctl status frobozz	Tells whether a service is currently running.
ls /etc/rc.d/init.d/	systemctl (or) systemctl list-unit-files --type=service (or) ls /lib/systemd/system/.service /etc/systemd/system/.service	Used to list the services that can be started or stopped. Used to list all the services and other units.
chkconfig frobozz on	syst

jrelo

[16:25:27] root@na:~ # echo "A"|xxd -b
0000000: 01000001 00001010                                      A.

[16:25:30] root@na:~ # echo "A"|perl -e '$byte=shift(@ARGV);$bit=shift(@ARGV);undef $/; $in=<>; substr($in,$byte,1) = substr($in,$byte,1) ^ chr(1<<$bit); print $in' 0 1|xxd -b
0000000: 01000011 00001010                                      C.

jrelo

Source material:
  http://security.stackexchange.com/questions/24444/what-is-the-most-hardened-set-of-options-for-gcc-compiling-c-c
  https://wiki.gentoo.org/wiki/Hardened_Gentoo
  https://wiki.debian.org/Hardening

================================================================================================================>
GCC Security related flags and options:

CFLAGS="-fPIE -fstack-protector-all -D_FORTIFY_SOURCE=2" 
LDFLAGS="-Wl,-z,now -Wl,-z,relro"

jrelo

Perl References

Simple Perl variables are called scalars. Examples of scalar values are

   $number      = 123;
   $string      = "String";
   $file_handle = open "<filename";
   $null_value  = undef;
 $reference = \"Reference of a String";

jrelo

#include <stdio.h>
#include <stdlib.h>
extern char** environ;

int main(int argc, char *argv[], char *envp[])
{
    int i;
    setenv("TESTVAR", "watvalue123", 1);

    printf("From char *envp[]:\n");

jrelo

#include <stdio.h>
#include <limits.h>

int main() {
  unsigned long long ulli;
  printf("%d", sizeof(ulli));
  printf("%llu\n", ULLONG_MAX);
  printf("%llu ... or \n", ~(unsigned long long)0);
  printf("%llu\n", (unsigned long long)0 - 1);
  return 0;

jrelo

#!/bin/bash

DEBUGFS=`grep debugfs /proc/mounts | awk '{ print $2; }'`

echo $$ > $DEBUGFS/tracing/set_ftrace_pid
echo function > $DEBUGFS/tracing/current_tracer
echo 1 > $DEBUGFS/tracing/tracing_on
exec $*
echo 0 > $DEBUGFS/tracing/tracing_on