[[PageOutline]]

 = 11/02 =
 == informative system calls ==
 * kernel/sys.c
  * sethostname, gethostname
  * about copy_to_user/copy_from_user
 * kernel/hrtimer.c
  * nanosleep
  * about timespec
 * kernel/posix-timers.c
  * clock_gettime
  * about timespec
 * kernel/module.c
  * delete_module
  * about strncpy_from_user
 * kernel/printk.c
  * about !__LOG_BUF_LEN/access_ok

 == testing new_debug syscall ==
 * windell57:i386 s0711489$ make -j2
{{{
Kernel: arch/x86/boot/bzImage is ready  (#3)
}}}

 * s0711489@ubuntu-lucid:~$ sudo /mnt/hgfs/tools/install.sh
 * s0711489@ubuntu-lucid:~$ sudo reboot

 * s0711489@ubuntu-lucid:~$ cat > new_debug-sys.c
 * s0711489@ubuntu-lucid:~$ gcc -I /lib/modules/2.6.35.14/build/arch/x86/include/ new_debug-sys.c

 * s0711489@ubuntu-lucid:~$ ./a.out
{{{
new_debug()
}}}
 * s0711489@ubuntu-lucid:~$ dmesg | tail -n 2
{{{
[    6.833440] dhclient3 used greatest stack depth: 5560 bytes left
[  579.378377] new_debug()
}}}
 * s0711489@ubuntu-lucid:~$ ./a.out hoge fuga piyo
{{{
[-570566464.-1216585740] hoge
[0.000000000] fuga
[0.000000000] piyo
}}}
 * s0711489@ubuntu-lucid:~$ dmesg | tail -n 5
{{{
[    6.833440] dhclient3 used greatest stack depth: 5560 bytes left
[  579.378377] new_debug()
[  596.785236] hoge
[  596.785274] fuga
[  596.785282] piyo
}}}

 == maybe useful ==
 * http://hira-consulting.com/wiki/index.php?linux2.6%2Farch%2Fi386%2Flib%2Fusercopy.c
 * http://hira-consulting.com/wiki/?linux2.6%2Finclude%2Flinux%2Ferr.h
 * IS_ERR_OR_NULL
 * !__LOG_BUF_LEN

 * https://www.codeblog.org/blog/gniibe/20060323.html
 * [https://www.codeblog.org/blog/gniibe/20060327.html#p02 get_user/put_user, set_fs のまとめ]
 * http://www.ibm.com/developerworks/jp/linux/library/l-system-calls/ の「copy_to_user」の定義が変
{{{
unsigned long copy_from_user( void *to, const void __user *from, unsigned long n );
unsigned long copy_to_user( void *to, const void __user *from, unsigned long n );
}}}
  * 以下が正しい
{{{
unsigned long copy_from_user( void *to, const void __user *from, unsigned long n );
unsigned long copy_to_user( void __user *to, const void *from, unsigned long n );
}}}