jos/user/faultallocbad.c
Anish Athalye da1f8392b1 Lab 4
2018-10-08 21:32:14 -07:00

25 lines
600 B
C

// test user-level fault handler -- alloc pages to fix faults
// doesn't work because we sys_cputs instead of cprintf (exercise: why?)
#include <inc/lib.h>
void
handler(struct UTrapframe *utf)
{
int r;
void *addr = (void*)utf->utf_fault_va;
cprintf("fault %x\n", addr);
if ((r = sys_page_alloc(0, ROUNDDOWN(addr, PGSIZE),
PTE_P|PTE_U|PTE_W)) < 0)
panic("allocating at %x in page fault handler: %e", addr, r);
snprintf((char*) addr, 100, "this string was faulted in at %x", addr);
}
void
umain(int argc, char **argv)
{
set_pgfault_handler(handler);
sys_cputs((char*)0xDEADBEEF, 4);
}