void set_task_stack_end_magic(struct task_struct *tsk)
{
unsigned long *stackend;
stackend = end_of_stack(tsk);
*stackend = STACK_END_MAGIC; /* for overflow detection */
}
static int __die(const char *str, int err, struct pt_regs *regs)
{
struct task_struct *tsk = current;
static int die_counter;
int ret;
pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
str, err, ++die_counter);
/* trap and error numbers are mostly meaningless on ARM */
ret = notify_die(DIE_OOPS, str, regs, err, 0, SIGSEGV);
if (ret == NOTIFY_STOP)
return ret;
print_modules();
__show_regs(regs);
pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk),
end_of_stack(tsk));
if (!user_mode(regs)) {
dump_backtrace(regs, tsk);
dump_instr(KERN_EMERG, regs);
}
return ret;
}
unsigned long get_wchan(struct task_struct *p)
{
unsigned long fp, lr;
unsigned long stack_start, stack_end;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
if (IS_ENABLED(CONFIG_FRAME_POINTER)) {
stack_start = (unsigned long)end_of_stack(p);
stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
fp = thread_saved_fp(p);
do {
if (fp < stack_start || fp > stack_end)
return 0;
lr = ((unsigned long *)fp)[0];
if (!in_sched_functions(lr))
return lr;
fp = *(unsigned long *)(fp + 4);
} while (count++ < 16);
}
return 0;
}
static struct task_struct *dup_task_struct(struct task_struct *orig)
{
struct task_struct *tsk;
struct thread_info *ti;
unsigned long *stackend;
int node = tsk_fork_get_node(orig);
int err;
prepare_to_copy(orig);
tsk = alloc_task_struct_node(node);
if (!tsk)
return NULL;
ti = alloc_thread_info_node(tsk, node);
if (!ti) {
free_task_struct(tsk);
return NULL;
}
err = arch_dup_task_struct(tsk, orig);
if (err)
goto out;
tsk->stack = ti;
err = prop_local_init_single(&tsk->dirties);
if (err)
goto out;
setup_thread_stack(tsk, orig);
clear_user_return_notifier(tsk);
clear_tsk_need_resched(tsk);
stackend = end_of_stack(tsk);
*stackend = STACK_END_MAGIC; /* for overflow detection */
#ifdef CONFIG_CC_STACKPROTECTOR
tsk->stack_canary = get_random_int();
#endif
/*
* One for us, one for whoever does the "release_task()" (usually
* parent)
*/
atomic_set(&tsk->usage, 2);
#ifdef CONFIG_BLK_DEV_IO_TRACE
tsk->btrace_seq = 0;
#endif
tsk->splice_pipe = NULL;
account_kernel_stack(ti, 1);
return tsk;
out:
free_thread_info(ti);
free_task_struct(tsk);
return NULL;
}
static struct task_struct *dup_task_struct(struct task_struct *orig)
{
struct task_struct *tsk;
struct thread_info *ti;
unsigned long *stackend;
int node = tsk_fork_get_node(orig);
int err;
prepare_to_copy(orig);
tsk = alloc_task_struct_node(node);
if (!tsk){
printk("[%d:%s] fork fail at alloc_tsk_node, please check kmem_cache_alloc_node()\n", current->pid, current->comm);
return NULL;
}
ti = alloc_thread_info_node(tsk, node);
if (!ti) {
printk("[%d:%s] fork fail at alloc_t_info_node, please check alloc_pages_node()\n", current->pid, current->comm);
free_task_struct(tsk);
return NULL;
}
err = arch_dup_task_struct(tsk, orig);
if (err){
printk("[%d:%s] fork fail at arch_dup_task_struct, err:%d \n", current->pid, current->comm, err);
goto out;
}
tsk->stack = ti;
setup_thread_stack(tsk, orig);
clear_user_return_notifier(tsk);
clear_tsk_need_resched(tsk);
stackend = end_of_stack(tsk);
*stackend = STACK_END_MAGIC; /* for overflow detection */
#ifdef CONFIG_CC_STACKPROTECTOR
tsk->stack_canary = get_random_int();
#endif
/*
* One for us, one for whoever does the "release_task()" (usually
* parent)
*/
atomic_set(&tsk->usage, 2);
#ifdef CONFIG_BLK_DEV_IO_TRACE
tsk->btrace_seq = 0;
#endif
tsk->splice_pipe = NULL;
account_kernel_stack(ti, 1);
return tsk;
out:
free_thread_info(ti);
free_task_struct(tsk);
return NULL;
}
static struct task_struct *dup_task_struct(struct task_struct *orig)
{
struct task_struct *tsk;
struct thread_info *ti;
unsigned long *stackend;
int node = tsk_fork_get_node(orig);
int err;
prepare_to_copy(orig);
tsk = alloc_task_struct_node(node);
if (!tsk)
return NULL;
ti = alloc_thread_info_node(tsk, node);
if (!ti) {
free_task_struct(tsk);
return NULL;
}
err = arch_dup_task_struct(tsk, orig);
if (err)
goto out;
tsk->stack = ti;
setup_thread_stack(tsk, orig);
clear_user_return_notifier(tsk);
clear_tsk_need_resched(tsk);
stackend = end_of_stack(tsk);
*stackend = STACK_END_MAGIC;
#ifdef CONFIG_CC_STACKPROTECTOR
tsk->stack_canary = get_random_int();
#endif
atomic_set(&tsk->usage, 2);
#ifdef CONFIG_BLK_DEV_IO_TRACE
tsk->btrace_seq = 0;
#endif
tsk->splice_pipe = NULL;
account_kernel_stack(ti, 1);
return tsk;
out:
free_thread_info(ti);
free_task_struct(tsk);
return NULL;
}
static phys_addr_t stack_page1_virt_to_phys(struct cpu_suspend_ctx *ptr)
{
struct thread_info *ti = current_thread_info();
if (virt_is_valid_lowmem(ti)) {
return virt_to_phys(ptr);
} else if (is_vmalloc_addr(ti)) {
unsigned long stack_page, low, high;
stack_page = (unsigned long)task_stack_page(current);
low = (unsigned long)end_of_stack(current);
high = stack_page + PAGE_SIZE - sizeof(struct cpu_suspend_ctx);
BUG_ON(((unsigned long)ptr < low) ||
((unsigned long)ptr >= high));
return ti->phys_addr + ((unsigned long)ptr - stack_page);
} else {
BUG();
}
}
static struct task_struct *dup_task_struct(struct task_struct *orig)
{
struct task_struct *tsk;
struct thread_info *ti;
unsigned long *stackend;
int node = tsk_fork_get_node(orig);
int err;
prepare_to_copy(orig);
tsk = alloc_task_struct_node(node);
if (!tsk)
return NULL;
ti = alloc_thread_info_node(tsk, node);
if (!ti) {
free_task_struct(tsk);
return NULL;
}
err = arch_dup_task_struct(tsk, orig);
if (err)
goto out;
tsk->stack = ti;
#ifdef CONFIG_SECCOMP
/*
* We must handle setting up seccomp filters once we're under
* the sighand lock in case orig has changed between now and
* then. Until then, filter must be NULL to avoid messing up
* the usage counts on the error path calling free_task.
*/
tsk->seccomp.filter = NULL;
#endif
setup_thread_stack(tsk, orig);
clear_user_return_notifier(tsk);
clear_tsk_need_resched(tsk);
stackend = end_of_stack(tsk);
*stackend = STACK_END_MAGIC; /* for overflow detection */
#ifdef CONFIG_CC_STACKPROTECTOR
tsk->stack_canary = get_random_int();
#endif
/*
* One for us, one for whoever does the "release_task()" (usually
* parent)
*/
atomic_set(&tsk->usage, 2);
#ifdef CONFIG_BLK_DEV_IO_TRACE
tsk->btrace_seq = 0;
#endif
tsk->splice_pipe = NULL;
account_kernel_stack(ti, 1);
return tsk;
out:
free_thread_info(ti);
free_task_struct(tsk);
return NULL;
}
/*
* 由do_fork()调用，为新的子进程创建task_struct, thread_info, 内核栈等信息
* 创建完成之后和父进程状态完全相同
*/
static struct task_struct *dup_task_struct(struct task_struct *orig)
{
struct task_struct *tsk;
struct thread_info *ti;
unsigned long *stackend;
int err;
prepare_to_copy(orig);
/* 申请task_struct内存空间 */
tsk = alloc_task_struct();
if (!tsk)
return NULL;
/* 申请thread_info内存空间 */
ti = alloc_thread_info(tsk);
if (!ti) {
/* 失败需要释放前面已经成功申请的task_struct内存空间，防止内存泄漏 */
free_task_struct(tsk);
return NULL;
}
/* 复制orig进程的信息到tsk进程中，复制完成后地址空间地址相同 */
err = arch_dup_task_struct(tsk, orig);
if (err)
goto out;
tsk->stack = ti;
/* 清空新进程的部分标志 */
err = prop_local_init_single(&tsk->dirties);
if (err)
goto out;
/* 新进程的进程栈信息 */
setup_thread_stack(tsk, orig);
/* 清除进程栈的部分信息 */
clear_user_return_notifier(tsk);
clear_tsk_need_resched(tsk);
stackend = end_of_stack(tsk);
*stackend = STACK_END_MAGIC; /* 用作内存越界检测 */
#ifdef CONFIG_CC_STACKPROTECTOR
tsk->stack_canary = get_random_int();
#endif
/* One for us, one for whoever does the "release_task()" (usually parent) */
atomic_set(&tsk->usage,2);
atomic_set(&tsk->fs_excl, 0);
#ifdef CONFIG_BLK_DEV_IO_TRACE
tsk->btrace_seq = 0;
#endif
tsk->splice_pipe = NULL;
/* 内核栈??? 干啥的??? */
account_kernel_stack(ti, 1);
return tsk;
out:
free_thread_info(ti);
free_task_struct(tsk);
return NULL;
}
