kernel-module

问题 Is it possible, to use a Loadable Kernel Module, compiled for 3.0.8+ mod_unload ARMv5 (my self-make'd kernel) in a kernel with version 3.0.31-gd5a18e0 SMP preempt mod_unload ARMv7 (android stock-kernel)? The module itself contains nearly nothing, just // Defining __KERNEL__ and MODULE allows us to access kernel-level code not usually available to userspace programs. #undef __KERNEL__ #define __KERNEL__ #undef MODULE #define MODULE // Linux Kernel/LKM headers: module.h is needed by all modules

问题 I'm working on a small firewall, i had to retrieve the datas from each tcp packet from port 80 (http) for parsing them. This code works well on a debian 32 bits virtual machine, i'm able to print the headers of each web page, but when i try to load my kernel module and to transfer some datas through the http port, it prints no datas. When i compile, it shows those warnings only on my 64bits computer : /home/dev3/C/FIREWALL/firewall.c: In function ‘hook_func’: /home/dev3/C/FIREWALL/firewall.c

问题 I want to compile my c code (in kernel) which needs to include some header files from another directory. Instead of specifying the complete path to header files in c file, I would like to specify the include path in Makefile. My c file gets complied when the config option CONFIG_FEATURE_X is enabled. I have written the following in Makefile: obj-$(CONFIG_FEATURE_X) += my_file.o ccflags-$(CONFIG_FEATURE_X) += -I$(obj)/../../path When the CONFIG_FEATURE_X is enabled (Y) in .config using make

问题 In a kernel module, how to list all the kernel symbols with their addresses? The kernel should not be re-compiled. I know "cat /proc/kallsyms" in an interface, but how to get them directly from kernel data structures, using functions like kallsyms_lookup_name . 回答1: Example Working module code: #include <linux/module.h> #include <linux/kallsyms.h> static int prsyms_print_symbol(void *data, const char *namebuf, struct module *module, unsigned long address) { pr_info("### %lx\t%s\n", address,

问题 I am trying to write a device driver and I need to use system() function in the driver. To use system() we need to include <stdlib.h> , which dosnt seem to work from a driver. It says no such file or directory found. Is there an alternative to stdlib.h for device drivers? Or an alternative to system() ? 回答1: stdlib.h is a user space header. User space is that set of memory locations in which user processes (i.e., everything other than the kernel) run. A process is an executing instance of a

问题 As part of my project I need to read the kernel to get the memory address of system call table and system call address. Or in effect i need to extract the contents of the system call table and all the system calls. Till now I use GDB for this purpose. Is there any way so that I could do it using a kernel module. I am new the kernel module programming. Looking for advice from experts here. 回答1: Let me first start by saying reading arbitrary kernel memory is tricky business! And there are many

问题 I want to access performance counters inside the kernel. I found many ways to use performance counters in user space, but can you tell me some way to use those in kernel space. Please don't specify tool name , I want to write my own code, preferably a kernel module. I am using Ubuntu with kernel 3.18.1. 回答1: http://www.cise.ufl.edu/~sb3/files/pmc.pdf http://www.cs.inf.ethz.ch/stricker/lab/doc/intel-part4.pdf The first pdf contains description on how to use pmc. The second contains the address

问题 I want to create a file under a /proc/driver directory. I would like to use a macro like proc_root_driver (or something else provided) rather than use "driver/MODULE_NAME" explicitly. I use create_proc_entry : struct proc_dir_entry *simpleproc_fops_entry; simpleproc_fops_entry = create_proc_entry(MODULE_NAME, 0400, NULL /* proc_root_dir */); After googling, I found suggestion to use proc_root_driver , but when I use it, I get the error proc_root_driver undeclared in this function And also,

问题 The task I am trying to achieve is actually quite simple (multicast the string "TEST" to a userland daemon), but the kernel module doesn't compile. It stops with the error: passing argument 4 of ‘genlmsg_multicast_allns’ makes integer from pointer without a cast [enabled by default] But shouldn't it just be the multicast group I defined? Here is the code for "clarification": #include <linux/module.h> #include <net/sock.h> #include <linux/netlink.h> #include <linux/skbuff.h> #include <linux

问题 When I try to rmmod a module I get the error message "Error: Module in use" , lsmod | grep <module name> shows the count. Is there a way that would tell me which processes are using this particular kernel module/driver? 回答1: This was asked before, but there was no great answer, probably because there is no good way to accomplish to find what is using what. The best suggestion is to dmesg and look for any indication of what loaded the module. You might also try using the --force parameter to