kernel-module

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/string.h> #include <net/netlink.h> #include <net/genetlink.h> struct sock *nl_sk = NULL; static void

I am wanting to use the function getname in my kernel module. It is not exported. Since I am running into this problem right now, I would like to know how to access and use any kernel symbol that is not exported. I figure that the steps necessary to use one will differ depending what the symbol is, so I'd like to see how it would be done for a type (e.g., a struct), a variable, a table of pointers (like the system call table), and a function. How can these be done in either of these cases: When I know the address of the symbol from System.map or /proc/kallsyms . When I know the name of the

What is the difference between device address , physical address and virtual address ? Actually I am trying for mmap in drivers, I am stuck on this concept. The documentation says: The kernel normally uses virtual addresses. Any address returned by kmalloc(), vmalloc(), and similar interfaces is a virtual address and can be stored in a "void *". The virtual memory system (TLB, page tables, etc.) translates virtual addresses to CPU physical addresses, which are stored as "phys_addr_t" or "resource_size_t". The kernel manages device resources like registers as physical addresses. These are the

I am using Linux 2.6.26 kernel version and I am trying to change the interrupt descriptor table using a kernel module. I am only trying to change the page fault table entry here. So I make a copy of the original IDT and make changes to the page fault table entry only. The objective of the ISR is to print out information of the page fault before calling the original Page fault handler. But the kernel just crashes once I load it with insmod i.e it specifically crashed with the "loadIDTR" function. With further debugging, I found out that by not changing any entry if I load the IDTR it works fine

I have a simple kernel object that I built for probing around at kernel memory. If I build it on my 64-bit Ubuntu (3.2) machine it works fine on that machine. But it won't insmod on my 64-bit Ubuntu (3.9) machine. And vice versa. It gives me a "-1 Invalid module format" error if I try to run it on a Kernel rev other than the one I'd built it on. I thought insmod linked it dynamically against the exported symbol table and the exported symbol table does not change between kernel revisions. (It gets appended.) Can someone tell me how I can build a kernel module (.ko) that is compatible with

I have a question when I located the address in kernel. I insert a hello module in kernel, in this module, I put these things: char mystring[]="this is my address"; printk("<1>The address of mystring is %p",virt_to_phys(mystring)); I think I can get the physical address of mystring, but what I found is, in syslog, the printed address of it is 0x38dd0000. However, I dumped the memory and found the real address of it is dcd2a000, which is quite different from the former one. How to explain this? I did something wrong? Thanks PS: I used a tool to dump the whole memory, physical addresses.