hello group, i am new to kernel programming. i want to have a communication between two modules. i found out from http://kernelnewbies.org/documents/kdoc/kernel-api/x7404.html that inter module communication can be acheived. i am trying out the inter module communciation and i find that i send info from one module(say module A) to the another(say module B) and make changes to the values in module A. the values in module B reflect post chances?. is there any other way that two modules can communicate in such a way thatthat the infomation is queued. i am sending my code and the output i got. can anyone tell me what went wrong. can anyone tell me if i can use EXPORT_SYMBOLS to achecive communication between the modules. thanks in advance gkgodava output: Hello, world - this is the kernel speaking :: foo 10 bar 100 Hello 1, world - this is the kernel speaking :: foo 123 bar 321 Hello 2, world - this is the kernel speaking :: foo 123 bar 321 expected output Hello, world - this is the kernel speaking :: foo 10 bar 100 Hello 1, world - this is the kernel speaking :: foo 10 bar 100 /**************************hello.h**********************************/ typedef struct { int fooptr; int barptr; } my_type_t; /**************************end of hello.h**************************/ /******************module 1*************************************/ /* The necessary header files */ /* Standard in kernel modules */ /* Deal with CONFIG_MODVERSIONS */ my_type_t mydata; /* Initialize the module */ int init_module() { mydata.fooptr = 10; mydata.barptr = 100; printk("Hello, world - this is the kernel speaking :: foo %d bar %d n", mydata.fooptr, mydata.barptr); inter_module_register(MY_STRING, THIS_MODULE, &mydata); (void) inter_module_put(MY_STRING); mydata.fooptr = 123; mydata.barptr = 321; /* If we return a non zero value, it means that * init_module failed and the kernel module * can't be loaded */ return 0; } /* Cleanup - undid whatever init_module did */ void cleanup_module() { inter_module_unregister(MY_STRING); printk("Short is the life of a kernel module n"); } MODULE_LICENSE("GPL"); /*******************end of module 1 *********************************/ /******************module 1*************************************/ /* Standard in kernel modules */ /* Deal with CONFIG_MODVERSIONS */ my_type_t *dataptr; int *modified; /* Initialize the module */ int init_module() { int foo; int bar; dataptr = (my_type_t *)inter_module_get(MY_STRING); foo = dataptr->fooptr; bar = dataptr->barptr; printk("Hello 1, world - this is the kernel speaking :: foo %d bar %d n",foo,bar); (void)inter_module_put(MY_STRING); dataptr = (my_type_t *)inter_module_get(MY_STRING); foo = dataptr->fooptr; bar = dataptr->barptr; printk("Hello 2, world - this is the kernel speaking :: foo %d bar %d n",foo,bar); /* If we return a non zero value, it means that * init_module failed and the kernel module * can't be loaded */ return 0; } /* Cleanup - undid whatever init_module did */ void cleanup_module() { printk("Short is the life of a kernel module n"); } MODULE_LICENSE("GPL"); /*******************end of module 1 *********************************/ -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
