kprobes sample driver (take 2)
PATCH 1/1 kprobes sample driver (take 2)
This is a resubmit of the kprobe sample driver with changes made from Vamsi's feedback with the exception of using kernel_text_address(addr) from arch/i386/kernel/traps.c. (I still need to get that working in my tree.)
As before ==>
This is a sample kprobes module that implements a simple misc char device that can cause arbitrary text to be printk'ed when arbitrary kernel addresses are executed.
This patch was created on top of a 2.5.47 kernel with the kprobes patch applied.
I created this driver just to learn what kprobes was all about. I am sending this to the mailing list for other people that are curious about kprobes (and also to have people who know more about kprobes show me where my understanding is flawed.)
To use the device, create a misc char node with a minor of 221, and then write strings of the format "0xADDRESS MESSAGE" to the device. When the file is closed all kprobes are unregistered, so I usually test by doing:
$ mknod /dev/noisy c 10 221 $ cat > /dev/noisy 0xc0107d50 sys_fork
.. and then go do something that will trigger a sys_fork.
-rustyl
drivers/char/Kconfig +15 -0
@@ -1270,5 +1270,20 @@ Once bound, I/O against /dev/raw/rawN uses efficient zero-copy I/O. See the raw(8) manpage for more details. +config NOISY + tristate "Noisy Interface Support" + ---help--- + If you say Y here and create a character special file /dev/noisy with + major number 10 and minor number 221 using mknod ("man mknod"), you + will get access to an interface for inserting arbitrary printk's + into executing kernel code. + + This driver is also available as a module ( = code which can be + inserted in and removed from the running kernel whenever you want). + The module is called noisy.o. If you want to compile it as a module, + say M here and read <file:Documentation/modules.txt>. + + If unsure, say N. + endmenu
drivers/char/Makefile +1 -0
@@ -102,6 +102,7 @@ obj-$(CONFIG_AGP) += agp/ obj-$(CONFIG_DRM) += drm/ obj-$(CONFIG_PCMCIA) += pcmcia/ +obj-$(CONFIG_NOISY) += noisy.o # Files generated that shall be removed upon make clean clean-files := consolemap_deftbl.c defkeymap.c qtronixmap.c
drivers/char/noisy.c +238 -0
238 lines not on this page · raw message
include/linux/miscdevice.h +1 -0
@@ -23,6 +23,7 @@#define MICROCODE_MINOR 184#define MWAVE_MINOR 219/* ACP/Mwave Modem */ #define MPT_MINOR 220 +#define NOISY_MINOR 221#define MISC_DYNAMIC_MINOR 255#define SGI_GRAPHICS_MINOR 146