kernel-module

I want to pass a string > 1024 chars to my module (filesystem). As kernel parameters are limited to 1024 chars, someone recommended to use sysfs instead. I tried to include this example in my super.c class to create a string 'filename' & string 'code' entry in sysfs for my module. static decl_subsys(myfs, NULL, NULL); struct myfs_attr { struct attribute attr; char *value; }; static struct myfs_attr fname = { .attr.name="filename", .attr.owner = THIS_MODULE, .attr.mode = 0644, .value = "/my/test/path", }; static struct myfs_attr code = { .attr.name="code", .attr.owner = THIS_MODULE, .attr.mode

I am trying to find a way, inside a module, to keep track of the last block written to a block device. The specific device I need is the one mounted at root (I know the /dev/ name ahead of time if that helps.) My original idea was to wrap the submit_bio function, since it has a logging function already if you "echo 1 > /proc/sys/vm/block_dump". Unfortunately it seems I'd need to modify the source code to make that function a pointer. I'd like to keep this all inside the module if at all possible. After that, I looked into finding the file system type, and wrapping the default file operations

I'm writing a kernel module and I need to hijack/wrap some sys calls. I'm brute-forcing the sys_call_table address and I'm using cr0 to disable/enable page protection. So far so good (I'll make public the entire code once it's done, so I can update this question if somebody wants). Anyways, I have noticed that if I hijack __NR_sys_read I get a kernel oops when I unload the kernel module, and also all konsoles (KDE) crash. Note that this doesn't happen with __NR_sys_open or __NR_sys_write . I'm wondering why is this happening. Any ideas? PS: Please don't go the KProbes way, I already know about