Help - how to pass an array of struct from one module to another?

[l x <whereisit28@yahoo.com>]

Hi,

I create two modules modA and modB (real files
attached below: modA.c, modB.c and modA.h).  I intend
to make them work like this:

- "insmod modA.o" will initialze the array of struct,
pA[0], pA[1] and pA[2].
- "insmod modB.o" will call the function
modA_func_1(ptr) defined in modA, which copies the the
pointers "ptr = pA".  I assume I should see the
following 3 line on the console:

################ ptr[0].i=0
################ ptr[1].i=10
################ ptr[2].i=20

But I only see 3 ramdom numbers (not 0, 10, 20).  This
means modA_func_1(ptr) defined in modA doesn't do "ptr
= pA" correctly, or somehow the ptr value gets changed
when function modA_func_1(ptr) returns. 

What I missed and how to pass an array of struct from
one module to another?

Thanks,

T.

/*************** modA.c ********************
#define MODULE
#include <linux/module.h>
#include "modA.h"

int init_module(void)
{
    printk("<0>Hello, world from modA\n");
   
    return 0;
}

void modA_func_1(void * ptr)
{
    A_struct *pA;
    int i;

    pA = (A_struct *) kmalloc(3*sizeof(A_struct));

    for(i=0; i<3; i++)
        pA[0].i = i * 10;

    ptr = pA;
}

EXPORT_SYMBOL_NOVERS(modA_func_1);

void cleanup_module(void)
{
    printk("<0>Goodbye world from modA\n");
}


/****************** modB.c *******************/
#define MODULE
#include <linux/module.h>

#include "modA.h"

extern void modA_func_1(struct A *ptr);

int init_module(void)
{
    A_struct * ptr;
    int i;

    ptr = (A_struct *) kmalloc(3*sizeof(A_struct));

    modA_func_1(ptr);

    for(i=0; i<3; i++)
        printk("<0>################ ptr[%d].i=%d\n",
i, ptr[i].i);

    return 0;
}

void cleanup_module(void)
{
    printk("<0>Goodbye world from modB\n");
}


/*************** modA.h **********************/
typedef struct A
{
    int i;
    char c;
} A_struct;




	
		
__________________________________
Do you Yahoo!?
Friends.  Fun.  Try the all-new Yahoo! Messenger.
http://messenger.yahoo.com/ 

--
Kernelnewbies: Help each other learn about the Linux kernel.
Archive:       http://mail.nl.linux.org/kernelnewbies/
FAQ:           http://kernelnewbies.org/faq/