Hello,
i have already writen onthis subject.
i have added function af_add() to icmp.c code that is called everytime ping
xx.xx.xx.xx is done.
this function is given some informative data as a param, and puts this into
buffer (kmalloced).
whenever buffer is full it swaps data from memory to file.
so i use
- spin_lock()/unlock() at the beginning and end of the func
- i kmalloc mem once at the first call to the fucntion af_add
- and switch between user/kernel when writing to file
That is all the idea.
But i get oops (but non-deterministically) when i try to run this (of course
after kernel compilation)
ooops says: sth about kernel BUG at sched.c 564 or somewhere else slub.c...
(i don personally think this is tru reason)
At the end of ooops there is: Kernel panic. Aiee, killing irq handler
In irq handler - not syncing
This is the code:
********************************************************
#define ELEMENT_MAX 4
#define write(f, buf, sz) (f->f_op->write(f, buf, sz, &f->f_pos))
struct element {
int data[16];
};
struct element *ptr=0;
unsigned int c_element = 0;
void af_add(struct element t) {
struct file *f;
char path[24];
mm_segment_t oldfs;
spinlock_t af_add_lock = SPIN_LOCK_UNLOCKED;
spin_lock(&af_add_lock); // or lock_kernel();
if ((c_element + 1) != ELEMENT_MAX){
if(!ptr) {
ptr = kmalloc(sizeof(struct element)*ELEMENT_MAX, GFP_KERNEL);
if(!ptr){
printk("nie moge zaalokowac mem..\n");
return;
}
}else{
memcpy(ptr + c_element, &t, sizeof(struct element));
}
}else {
snprintf(path, sizeof(path), "/tmp/dumplog"); // open file
f = filp_open(path, O_CREAT | O_APPEND, 00600);
if (IS_ERR(f) || !f) { // check if it
properly opened
printk("blad przy otwieraniu..\n");
return;
}
oldfs = get_fs(); // switch
user/kernel
set_fs(get_ds());
printk("write: %d\n", write(f, (void *) ptr, sizeof(struct
element) * ELEMENT_MAX)); // write to file
set_fs(oldfs);
filp_close(f, 0);
c_swap++;
c_element = 0;
}
c_element++;
spin_unlock(&af_add_lock); // or unlock_kernel();
}
***************************************************************
This is added to icmp.c code just to be able to test easily.
In icmp.c it is called for every packet like this:
***************************************
static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
{
... /* original icmp.c code */
struct element t;
int ii;
// for(ii=0; ii<8; ii++)
t.data[0]=222;
af_add(t);
... /* original icmp.c code */
}
***************************************
And sometimes it works .. .some strange data are writen to dumplog file.....
please help this is part of my research.. and i can not go ANY FURTHER
witouh it
thank you in advance
adam
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