I'm trying to get a kernel module to load at boot. If I run insmod /path/to/module.ko, it works fine. But this has to be repeated every time I reboot. If I run modprobe /path/to/module.ko, it can't find the module. I know modprobe uses a configuration file, but I can't get it to load the module even after adding /path/to/module.ko to /...
I'm writing a Linux kernel module that needs to open and read files. What's the best way to accomplish that? ...
I'm writting a Linux module (Kernel Programming), and I`m getting: "Unable to handle kernel NULL pointer dereference" What does it mean? ...
If I load a kernel module and list the loaded modules with lsmod, I can get the "use count" of the module (number of other modules with a reference to the module). Is there a way to figure out what is using a module, though? The issue is that a module I am developing insists its use count is 1 and thus I cannot use rmmod to unload it, b...
I'd like to add a new system call via an LKM, but I'm not sure how to do this. That is, I know that if I want to add a completely new system call, I can look through the sys_call_table and find a sys_ni_syscall and just replace it, but I was curious if it was possible to actually add to the sys_call_table. I realize it's probably not pos...
New to Linux programming in general. I am trying to communicate with a kernel module via shared memory, but cannot call the functions used in user apps such as shmget(); I have installed kernel-headers and kernel-devel, and included , to the kernel module source, but the headers do not contain any functions. Is there a standard way of...
I want to create a proc file under /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...
While compiling Linux kernel modules that depend on each other, linker gives undefined symbol warnings like Building modules, stage 2. MODPOST *** Warning: "function_name1" [module_name] undefined! *** Warning: "function_name2" [module_name] undefined! *** Warning: "function_name3" [module_name] undefined! The unresolved symbols ar...
I was browsing for an open source kernel when I ran across SANOS which feels like something worth keeping alive as open source. To bring it up to modern standards, the following enhancements need to occur: Support for Multiple CPUs/Cores Add IPv6 (currently only supports IPv4) Ability to run 8192 concurrent threads Ability to support ...
I'm trying to use a somewhat old DAQ, and had to jump through a few hoops to get an old (circa 2004) device driver for it to compile (DTI-DT340 Linux-DAQ-PCI). I've gotten to the point where it compiles, I can load the the kernel module, it finds the card, and I can create the character devices using mknod. But I can't seem to open the...
Is it possible to compile a linux kernel(2.6) module that includes functionality defined by non-kernel includes? For example: kernelmodule.h #include <linux/init.h> #include <linux/module.h> #include <linux/kernel.h> // printk() // ... #include <openssl/sha.h> // ... Makefile obj-m := kernelmodule.o all: $(MAKE) -C /lib/mo...
How to intercept system calls on aix 5.3 or aix 6.1? ...
How can the CPU affinity of a process be set in kernel module? In user mode there is a syscall sched_setaffinity, but I am looking for the kernel mode equivalent. In the Linux kernel code, there is also a function called sched_setaffinity. It's called from the sys_sched_setaffinity function which is called by system_call. From what i...
I know all the discussions about why one should not read/write files from kernel, instead how to use /proc or netlink to do that. I want to read/write anyway. I have also read http://www.linuxjournal.com/article/8110 However, problem is 2.6.30 does not export sys_read(). Rather its wrapped in SYSCALL_DEFINE3. So if I use that in my mod...
Hi, Im getting into kernel work for a bit of my summer research. We are looking to make modifications to the TCP, in specific RTT calculations. What I would like to do is replace the resolution of one of the functions in tcp_input.c to a function provided by a dynamically loaded kernel module. I think this would improve the pace at w...
I am writing kernel module(C in Linux) and I want to change the permission of the other files in it. any solution? since I am in kernel I can't use chmod syscall and ... thanks for your help This is my Makefile: > obj-m += ca.o > > all: > make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules > > clean: > ...
I compiled and ran the chardev.c example from the lkmpg and when writing to the device received an unexpected error: anon@anon:~/lkmpg$ sudo echo "hi" > /dev/chardev bash: /dev/chardev: Permission denied The module write function looks like this: /* * Called when a process writes to dev file: echo "hi" > /dev/chardev */ static s...
I was reading the LKMPG ( See Section 4.1.4. Unregistering A Device ) and it wasn't clear to me when to use the try_module_get / module_put functions. Some of the LKMPG examples use them, some don't. To add to the confusion, try_module_get appears 282 times in 193 files in the 2.6.24 source, yet in Linux Device Drivers ( LDD3 ) and Ess...
Hello all; I'm working on modifying a Linux 2.6.22-5 kernel driver in order to add threading, and I'm running into a problem I can't seem to figure out. I have set up the module so that there is a single function which is called, which invokes one or more worker threads to do the actual work. The worker threads contain only existing f...
Hello, I'd like pass a pointer from a user space memory into a function in my kernel module. I don't want to use copy_from_user. I've read that I should use get_user_pages function. For example one page. struct page **pages; pages = kmalloc(1 * sizeof(*pages), GFP_KERNEL); down_read(¤t->mm->mmap_sem); get_user_pages(current,cur...