Hi all,
We work on LINUX 2.2.13 and RTL 2.0.
When a RT task produces a page fault (bad pointer, ....: see the
following code),
the exception function (do_page_fault: arch/i386/mm/fault.c)
also produces a page fault -> infinite loop.
>From a RT task, it seems that the current task structure is not valide
(tsk variable in do_page_fault function: tsk = current;).
Is it normal ????
How to solve the problem and display information about the page fault ?
If this page fault is produced in a simple module (not from a RT task),
the panic displays all the informations about the access (address, IP,
stack, ...).
For debugging it is very useful.
Many thanks.
Denis
#include <rtl.h>
#include <rtl_sched.h>
#include <linux/module.h>
RT_TASK k_test_task;
int nb;
void k_test(int data) {
char *ptr = 0;
for (;;) {
rtl_printf("k_test: %d\n", nb);
rtl_printf("ptr=0x%x\n", ptr);
rtl_printf("Before access in zero\n");
*ptr = 0; /* Access in zero to produce a page fault */
rtl_printf("After access in zero\n");
nb++;
rt_task_wait();
}
}
int init_module(void) {
nb = 0;
/* Create task */
if (rt_task_init(&k_test_task, k_test, 0, 8192, 1) < 0) {
printk("init_module: Error rt_task_init\n");
return(-1);
}
if (rt_task_make_periodic(&k_test_task, rt_get_time() +
(RTIME)(RT_TICKS_PER_SEC * 2),
(RTIME)(RT_TICKS_PER_SEC * 5)) < 0) {
printk("init_module: Error rt_task_make_periodic\n");
return(-1);
}
return(0);
}
void cleanup_module(void) {
rt_task_delete(&k_test_task);
rtl_printf("Cleanup module\n");
}
-- [rtl] ---
To unsubscribe:
echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR
echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED]
---
For more information on Real-Time Linux see:
http://www.rtlinux.org/rtlinux/
