void lkdtm_WRITE_KERN(void)
{
size_t size;
unsigned char *ptr;
size = (unsigned long)do_overwritten - (unsigned long)do_nothing;
ptr = (unsigned char *)do_overwritten;
pr_info("attempting bad %zu byte write at %p\n", size, ptr);
memcpy(ptr, (unsigned char *)do_nothing, size);
flush_icache_range((unsigned long)ptr, (unsigned long)(ptr + size));
do_overwritten();
}
static void lkdtm_do_action(enum ctype which)
{
switch (which) {
case CT_PANIC:
panic("dumptest");
break;
case CT_BUG:
BUG();
break;
case CT_WARNING:
WARN_ON(1);
break;
case CT_EXCEPTION:
*((int *) 0) = 0;
break;
case CT_LOOP:
for (;;)
;
break;
case CT_OVERFLOW:
(void) recursive_loop(recur_count);
break;
case CT_CORRUPT_STACK:
corrupt_stack();
break;
case CT_UNALIGNED_LOAD_STORE_WRITE: {
static u8 data[5] __attribute__((aligned(4))) = {1, 2,
3, 4, 5};
u32 *p;
u32 val = 0x12345678;
p = (u32 *)(data + 1);
if (*p == 0)
val = 0x87654321;
*p = val;
break;
}
case CT_OVERWRITE_ALLOCATION: {
size_t len = 1020;
u32 *data = kmalloc(len, GFP_KERNEL);
data[1024 / sizeof(u32)] = 0x12345678;
kfree(data);
break;
}
case CT_WRITE_AFTER_FREE: {
size_t len = 1024;
u32 *data = kmalloc(len, GFP_KERNEL);
kfree(data);
schedule();
memset(data, 0x78, len);
break;
}
case CT_SOFTLOCKUP:
preempt_disable();
for (;;)
cpu_relax();
break;
case CT_HARDLOCKUP:
local_irq_disable();
for (;;)
cpu_relax();
break;
case CT_SPINLOCKUP:
/* Must be called twice to trigger. */
spin_lock(&lock_me_up);
/* Let sparse know we intended to exit holding the lock. */
__release(&lock_me_up);
break;
case CT_HUNG_TASK:
set_current_state(TASK_UNINTERRUPTIBLE);
schedule();
break;
case CT_EXEC_DATA:
execute_location(data_area);
break;
case CT_EXEC_STACK: {
u8 stack_area[EXEC_SIZE];
execute_location(stack_area);
break;
}
case CT_EXEC_KMALLOC: {
u32 *kmalloc_area = kmalloc(EXEC_SIZE, GFP_KERNEL);
execute_location(kmalloc_area);
kfree(kmalloc_area);
break;
}
case CT_EXEC_VMALLOC: {
u32 *vmalloc_area = vmalloc(EXEC_SIZE);
execute_location(vmalloc_area);
vfree(vmalloc_area);
break;
}
case CT_EXEC_USERSPACE: {
unsigned long user_addr;
user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_ANONYMOUS | MAP_PRIVATE, 0);
if (user_addr >= TASK_SIZE) {
pr_warn("Failed to allocate user memory\n");
return;
}
execute_user_location((void *)user_addr);
vm_munmap(user_addr, PAGE_SIZE);
break;
}
case CT_ACCESS_USERSPACE: {
unsigned long user_addr, tmp;
unsigned long *ptr;
user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_ANONYMOUS | MAP_PRIVATE, 0);
if (user_addr >= TASK_SIZE) {
pr_warn("Failed to allocate user memory\n");
return;
}
ptr = (unsigned long *)user_addr;
pr_info("attempting bad read at %p\n", ptr);
tmp = *ptr;
tmp += 0xc0dec0de;
pr_info("attempting bad write at %p\n", ptr);
*ptr = tmp;
vm_munmap(user_addr, PAGE_SIZE);
break;
}
case CT_WRITE_RO: {
unsigned long *ptr;
ptr = (unsigned long *)&rodata;
pr_info("attempting bad write at %p\n", ptr);
*ptr ^= 0xabcd1234;
break;
}
case CT_WRITE_KERN: {
size_t size;
unsigned char *ptr;
size = (unsigned long)do_overwritten -
(unsigned long)do_nothing;
ptr = (unsigned char *)do_overwritten;
pr_info("attempting bad %zu byte write at %p\n", size, ptr);
memcpy(ptr, (unsigned char *)do_nothing, size);
flush_icache_range((unsigned long)ptr,
(unsigned long)(ptr + size));
do_overwritten();
break;
}
case CT_NONE:
default:
break;
}
}