int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
unsigned long stack_top, struct task_struct * p,
struct pt_regs *regs)
{
void (*handler)(int);
if(current->thread.forking){
memcpy(&p->thread.regs.regs.skas, ®s->regs.skas,
sizeof(p->thread.regs.regs.skas));
REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.skas.regs, 0);
if(sp != 0) REGS_SP(p->thread.regs.regs.skas.regs) = sp;
handler = fork_handler;
arch_copy_thread(¤t->thread.arch, &p->thread.arch);
}
else {
init_thread_registers(&p->thread.regs.regs);
p->thread.request.u.thread = current->thread.request.u.thread;
handler = new_thread_handler;
}
new_thread(task_stack_page(p), &p->thread.mode.skas.switch_buf,
&p->thread.mode.skas.fork_buf, handler);
return(0);
}
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_mem(KERN_EMERG, "Stack: ", regs->sp,
THREAD_SIZE + (unsigned long)task_stack_page(tsk));
dump_backtrace(regs, tsk);
dump_instr(KERN_EMERG, regs);
}
return ret;
}
/*
* Return saved PC of a blocked thread. used in kernel/sched.
* resume in entry.S does not create a new stack frame, it
* just stores the registers %r6-%r15 to the frame given by
* schedule. We want to return the address of the caller of
* schedule, so we have to walk the backchain one time to
* find the frame schedule() store its return address.
*/
unsigned long thread_saved_pc(struct task_struct *tsk)
{
struct stack_frame *sf, *low, *high;
if (!tsk || !task_stack_page(tsk))
return 0;
low = task_stack_page(tsk);
high = (struct stack_frame *) task_pt_regs(tsk);
sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN);
if (sf <= low || sf > high)
return 0;
sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
if (sf <= low || sf > high)
return 0;
return sf->gprs[8];
}
int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
{
int ret;
/*
* We need to tell the secondary core where to find its stack and the
* page tables.
*/
secondary_data.stack = task_stack_page(idle) + THREAD_START_SP;
__flush_dcache_area(&secondary_data, sizeof(secondary_data));
/*
* Now bring the CPU into our world.
*/
ret = boot_secondary(cpu, idle);
if (ret == 0) {
/*
* CPU was successfully started, wait for it to come online or
* time out.
*/
wait_for_completion_timeout(&cpu_running,
msecs_to_jiffies(1000));
if (!cpu_online(cpu)) {
pr_crit("CPU%u: failed to come online\n", cpu);
ret = -EIO;
}
} else {
pr_err("CPU%u: failed to boot: %d\n", cpu, ret);
}
secondary_data.stack = NULL;
return ret;
}
unsigned long get_wchan(struct task_struct *p)
{
unsigned long bp, sp, ip;
unsigned long stack_page;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_page = (unsigned long)task_stack_page(p);
sp = p->thread.sp;
if (!stack_page || sp < stack_page || sp > top_esp+stack_page)
return 0;
/* L4Linux has a different layout in switch_to(), but
* the only difference is that we push a return
* address after ebp. So we simply adjust the esp to
* reflect that. And we leave the different name for
* esp to catch direct usage of thread data. */
sp += 4;/* add 4 to remove return address */
/* include/asm-i386/system.h:switch_to() pushes bp last. */
bp = *(unsigned long *) sp;
do {
if (bp < stack_page || bp > top_ebp+stack_page)
return 0;
ip = *(unsigned long *) (bp+4);
if (!in_sched_functions(ip))
return ip;
bp = *(unsigned long *) bp;
} while (count++ < 16);
return 0;
}
static enum stack_type
analyze_stack(int cpu, struct task_struct *task, unsigned long *stack,
unsigned long **stack_end, unsigned long *irq_stack,
unsigned *used, char **id)
{
unsigned long addr;
addr = ((unsigned long)stack & (~(THREAD_SIZE - 1)));
if ((unsigned long)task_stack_page(task) == addr)
return STACK_IS_NORMAL;
*stack_end = in_exception_stack(cpu, (unsigned long)stack,
used, id);
if (*stack_end)
return STACK_IS_EXCEPTION;
if (!irq_stack)
return STACK_IS_NORMAL;
*stack_end = irq_stack;
irq_stack = irq_stack - irq_stack_size;
if (in_irq_stack(stack, irq_stack, *stack_end))
return STACK_IS_IRQ;
return STACK_IS_UNKNOWN;
}
void __noreturn die(const char *str, struct pt_regs *regs,
long err, unsigned long addr)
{
static int die_counter;
oops_enter();
spin_lock_irq(&die_lock);
console_verbose();
bust_spinlocks(1);
pr_err("%s: err %04lx (%s) addr %08lx [#%d]\n", str, err & 0xffff,
trap_name(err & 0xffff), addr, ++die_counter);
print_modules();
show_regs(regs);
pr_err("Process: %s (pid: %d, stack limit = %p)\n", current->comm,
task_pid_nr(current), task_stack_page(current) + THREAD_SIZE);
bust_spinlocks(0);
add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
if (kexec_should_crash(current))
crash_kexec(regs);
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception");
spin_unlock_irq(&die_lock);
oops_exit();
do_exit(SIGSEGV);
}
bool in_task_stack(unsigned long *stack, struct task_struct *task,
struct stack_info *info)
{
unsigned long *begin = task_stack_page(task);
unsigned long *end = task_stack_page(task) + THREAD_SIZE;
if (stack < begin || stack >= end)
return false;
info->type = STACK_TYPE_TASK;
info->begin = begin;
info->end = end;
info->next_sp = NULL;
return true;
}
static void __kasan_unpoison_stack(struct task_struct *task, const void *sp)
{
void *base = task_stack_page(task);
size_t size = sp - base;
kasan_unpoison_shadow(base, size);
}
/*
* get_wchan - a maintenance nightmare^W^Wpain in the ass ...
*/
unsigned long get_wchan(struct task_struct *task)
{
unsigned long pc = 0;
#ifdef CONFIG_KALLSYMS
unsigned long sp;
unsigned long ra = 0;
#endif
if (!task || task == current || task->state == TASK_RUNNING)
goto out;
if (!task_stack_page(task))
goto out;
pc = thread_saved_pc(task);
#ifdef CONFIG_KALLSYMS
sp = task->thread.reg29 + schedule_mfi.frame_size;
while (in_sched_functions(pc))
pc = unwind_stack(task, &sp, pc, &ra);
#endif
out:
return pc;
}
static int __die(const char *str, int err, struct thread_info *thread,
struct pt_regs *regs)
{
unsigned long sp, stack;
struct task_struct *tsk = thread->task;
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), thread + 1);
if (!user_mode(regs) || in_interrupt()) {
sp = regs->sp;
stack = (unsigned long)task_stack_page(tsk);
dump_mem(KERN_EMERG, "Stack: ", sp, ALIGN(sp, THREAD_SIZE));
if (sp < stack || (sp - stack) > THREAD_SIZE) {
printk(KERN_EMERG "Invalid sp[%lx] or stack address[%lx]\n", sp, stack);
dump_mem(KERN_EMERG, "Stack(backup) ", stack, THREAD_SIZE + stack);
}
dump_backtrace(regs, tsk);
dump_instr(KERN_EMERG, regs);
}
return ret;
}
/*
* Write contents of register REGNO in task TASK.
*/
static inline int
put_reg(struct task_struct *task, int regno, unsigned long data)
{
char *reg_ptr;
struct pt_regs *regs =
(struct pt_regs *)((unsigned long)task_stack_page(task) +
(THREAD_SIZE - sizeof(struct pt_regs)));
reg_ptr = (char *)regs;
switch (regno) {
case PT_PC:
/*********************************************************************/
/* At this point the kernel is most likely in exception. */
/* The RETX register will be used to populate the pc of the process. */
/*********************************************************************/
regs->retx = data;
regs->pc = data;
break;
case PT_RETX:
break; /* regs->retx = data; break; */
case PT_USP:
regs->usp = data;
task->thread.usp = data;
break;
default:
if (regno <= 216)
*(long *)(reg_ptr + regno) = data;
}
return 0;
}
/*
* Checks if a given pointer and length is contained by the current
* stack frame (if possible).
*
* 0: not at all on the stack
* 1: fully within a valid stack frame
* 2: fully on the stack (when can't do frame-checking)
* -1: error condition (invalid stack position or bad stack frame)
*/
static noinline int check_stack_object(const void *obj, unsigned long len)
{
const void * const stack = task_stack_page(current);
const void * const stackend = stack + THREAD_SIZE;
int ret;
/* Object is not on the stack at all. */
if (obj + len <= stack || stackend <= obj)
return NOT_STACK;
/*
* Reject: object partially overlaps the stack (passing the
* the check above means at least one end is within the stack,
* so if this check fails, the other end is outside the stack).
*/
if (obj < stack || stackend < obj + len)
return BAD_STACK;
/* Check if object is safely within a valid frame. */
ret = arch_within_stack_frames(stack, stackend, obj, len);
if (ret)
return ret;
return GOOD_STACK;
}
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;
}
void dump_trace(struct task_struct *task, struct pt_regs *regs,
unsigned long *stack, unsigned long bp,
const struct stacktrace_ops *ops, void *data)
{
int graph = 0;
if (!task)
task = current;
if (!stack) {
unsigned long dummy;
stack = &dummy;
if (task && task != current)
stack = (unsigned long *)task->thread.sp;
}
if (!bp)
bp = stack_frame(task, regs);
for (;;) {
void *stack_start = (void *)((unsigned long)stack & ~(THREAD_SIZE-1));
bp = ops->walk_stack(task, stack_start, stack, bp, ops, data, NULL, &graph);
if (stack_start == task_stack_page(task))
break;
stack = *(unsigned long **)stack_start;
if (ops->stack(data, "IRQ") < 0)
break;
touch_nmi_watchdog();
}
}
static void save_context_stack(struct stack_trace *trace, struct pt_regs *regs)
{
unsigned long sp = regs->regs[29];
#ifdef CONFIG_KALLSYMS
unsigned long ra = regs->regs[31];
unsigned long pc = regs->cp0_epc;
if (raw_show_trace || !__kernel_text_address(pc)) {
unsigned long stack_page =
(unsigned long)task_stack_page(current);
if (stack_page && sp >= stack_page &&
sp <= stack_page + THREAD_SIZE - 32)
save_raw_context_stack(trace, sp);
return;
}
do {
if (trace->skip > 0)
trace->skip--;
else
trace->entries[trace->nr_entries++] = pc;
if (trace->nr_entries >= trace->max_entries)
break;
pc = unwind_stack(current, &sp, pc, &ra);
} while (pc);
#else
save_raw_context_stack(trace, sp);
#endif
}
void save_stack_trace(struct stack_trace *trace)
{
unsigned long low, high;
unsigned long fp;
struct stackframe *frame;
int skip = trace->skip;
low = (unsigned long)task_stack_page(current);
high = low + THREAD_SIZE;
fp = current_frame_pointer;
while (fp >= low && fp <= (high - sizeof(*frame))) {
frame = (struct stackframe *)fp;
if (skip) {
skip--;
} else {
trace->entries[trace->nr_entries++] = frame->rets;
if (trace->nr_entries >= trace->max_entries)
break;
}
/*
*/
low = fp + sizeof(*frame);
fp = frame->fp;
}
}
static int __cpuinit xen_cpu_up(unsigned int cpu)
{
struct task_struct *idle = idle_task(cpu);
int rc;
per_cpu(current_task, cpu) = idle;
#ifdef CONFIG_X86_32
irq_ctx_init(cpu);
#else
clear_tsk_thread_flag(idle, TIF_FORK);
per_cpu(kernel_stack, cpu) =
(unsigned long)task_stack_page(idle) -
KERNEL_STACK_OFFSET + THREAD_SIZE;
per_cpu(kernel_stack8k, cpu) =
(unsigned long)task_stack_page(idle) -
KERNEL_STACK_OFFSET + THREAD_SIZE - 8192;
#endif
xen_setup_runstate_info(cpu);
xen_setup_timer(cpu);
xen_init_lock_cpu(cpu);
per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
/* make sure interrupts start blocked */
per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
rc = cpu_initialize_context(cpu, idle);
if (rc)
return rc;
if (num_online_cpus() == 1)
alternatives_smp_switch(1);
rc = xen_smp_intr_init(cpu);
if (rc)
return rc;
rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
BUG_ON(rc);
while(per_cpu(cpu_state, cpu) != CPU_ONLINE) {
HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
barrier();
}
return 0;
}
int
copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long unused, struct task_struct *p, struct pt_regs *regs)
{
struct pt_regs *childregs;
struct pt_regs *kregs;
unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
struct thread_info *ti;
unsigned long top_of_kernel_stack;
top_of_kernel_stack = sp;
p->set_child_tid = p->clear_child_tid = NULL;
sp -= STACK_FRAME_OVERHEAD;
sp -= sizeof(struct pt_regs);
childregs = (struct pt_regs *)sp;
*childregs = *regs;
if ((childregs->sr & SPR_SR_SM) == 1) {
childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
childregs->gpr[10] = (unsigned long)task_thread_info(p);
} else {
childregs->sp = usp;
}
childregs->gpr[11] = 0;
sp -= STACK_FRAME_OVERHEAD;
sp -= sizeof(struct pt_regs);
kregs = (struct pt_regs *)sp;
ti = task_thread_info(p);
ti->ksp = sp;
kregs->sp = top_of_kernel_stack;
kregs->gpr[3] = (unsigned long)current;
kregs->gpr[10] = (unsigned long)task_thread_info(p);
kregs->gpr[9] = (unsigned long)ret_from_fork;
return 0;
}
static bool in_task_stack(unsigned long sp, struct task_struct *task,
struct stack_info *info)
{
unsigned long stack;
stack = (unsigned long) task_stack_page(task);
return in_stack(sp, info, STACK_TYPE_TASK, stack, stack + THREAD_SIZE);
}
int copy_thread_tt(int nr, unsigned long clone_flags, unsigned long sp,
unsigned long stack_top, struct task_struct * p,
struct pt_regs *regs)
{
int (*tramp)(void *);
int new_pid, err;
unsigned long stack;
if(current->thread.forking)
tramp = fork_tramp;
else {
tramp = new_thread_proc;
p->thread.request.u.thread = current->thread.request.u.thread;
}
err = os_pipe(p->thread.mode.tt.switch_pipe, 1, 1);
if(err < 0){
printk("copy_thread : pipe failed, err = %d\n", -err);
return(err);
}
stack = alloc_stack(0, 0);
if(stack == 0){
printk(KERN_ERR "copy_thread : failed to allocate "
"temporary stack\n");
return(-ENOMEM);
}
clone_flags &= CLONE_VM;
p->thread.temp_stack = stack;
new_pid = start_fork_tramp(task_stack_page(p), stack, clone_flags, tramp);
if(new_pid < 0){
printk(KERN_ERR "copy_thread : clone failed - errno = %d\n",
-new_pid);
return(new_pid);
}
if(current->thread.forking){
sc_to_sc(UPT_SC(&p->thread.regs.regs), UPT_SC(®s->regs));
SC_SET_SYSCALL_RETURN(UPT_SC(&p->thread.regs.regs), 0);
if(sp != 0)
SC_SP(UPT_SC(&p->thread.regs.regs)) = sp;
}
p->thread.mode.tt.extern_pid = new_pid;
current->thread.request.op = OP_FORK;
current->thread.request.u.fork.pid = new_pid;
os_usr1_process(os_getpid());
/* Enable the signal and then disable it to ensure that it is handled
* here, and nowhere else.
*/
change_sig(SIGUSR1, 1);
change_sig(SIGUSR1, 0);
err = 0;
return(err);
}
int start_uml_tt(void)
{
void *sp;
int pages;
pages = (1 << CONFIG_KERNEL_STACK_ORDER);
sp = task_stack_page(&init_task) +
pages * PAGE_SIZE - sizeof(unsigned long);
return(tracer(start_kernel_proc, sp));
}
unsigned long get_wchan(struct task_struct *task)
{
if (!task || task == current || task->state == TASK_RUNNING)
return 0;
if (!task_stack_page(task))
return 0;
return task_pt_regs(task)->cp0_epc;
}
/*
* Called from fs/proc with a reference on @p to find the function
* which called into schedule(). This needs to be done carefully
* because the task might wake up and we might look at a stack
* changing under us.
*/
unsigned long get_wchan(struct task_struct *p)
{
unsigned long start, bottom, top, sp, fp, ip, ret = 0;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
if (!try_get_task_stack(p))
return 0;
start = (unsigned long)task_stack_page(p);
if (!start)
goto out;
/*
* Layout of the stack page:
*
* ----------- topmax = start + THREAD_SIZE - sizeof(unsigned long)
* PADDING
* ----------- top = topmax - TOP_OF_KERNEL_STACK_PADDING
* stack
* ----------- bottom = start
*
* The tasks stack pointer points at the location where the
* framepointer is stored. The data on the stack is:
* ... IP FP ... IP FP
*
* We need to read FP and IP, so we need to adjust the upper
* bound by another unsigned long.
*/
top = start + THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING;
top -= 2 * sizeof(unsigned long);
bottom = start;
sp = READ_ONCE(p->thread.sp);
if (sp < bottom || sp > top)
goto out;
fp = READ_ONCE_NOCHECK(((struct inactive_task_frame *)sp)->bp);
do {
if (fp < bottom || fp > top)
goto out;
ip = READ_ONCE_NOCHECK(*(unsigned long *)(fp + sizeof(unsigned long)));
if (!in_sched_functions(ip)) {
ret = ip;
goto out;
}
fp = READ_ONCE_NOCHECK(*(unsigned long *)fp);
} while (count++ < 16 && p->state != TASK_RUNNING);
out:
put_task_stack(p);
return ret;
}
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
unsigned long sp, low, high;
sp = tsk->thread.ksp & PSW_ADDR_INSN;
low = (unsigned long) task_stack_page(tsk);
high = (unsigned long) task_pt_regs(tsk);
save_context_stack(trace, sp, low, high, 0);
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
/*
* Copy architecture-specific thread state
*/
int
copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long kthread_arg, struct task_struct *p)
{
struct pt_regs *cregs = &(p->thread.regs);
void *stack = task_stack_page(p);
/* We have to use void * instead of a function pointer, because
* function pointers aren't a pointer to the function on 64-bit.
* Make them const so the compiler knows they live in .text */
extern void * const ret_from_kernel_thread;
extern void * const child_return;
if (unlikely(p->flags & PF_KTHREAD)) {
/* kernel thread */
memset(cregs, 0, sizeof(struct pt_regs));
if (!usp) /* idle thread */
return 0;
/* Must exit via ret_from_kernel_thread in order
* to call schedule_tail()
*/
cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
cregs->kpc = (unsigned long) &ret_from_kernel_thread;
/*
* Copy function and argument to be called from
* ret_from_kernel_thread.
*/
#ifdef CONFIG_64BIT
cregs->gr[27] = ((unsigned long *)usp)[3];
cregs->gr[26] = ((unsigned long *)usp)[2];
#else
cregs->gr[26] = usp;
#endif
cregs->gr[25] = kthread_arg;
} else {
/* user thread */
/* usp must be word aligned. This also prevents users from
* passing in the value 1 (which is the signal for a special
* return for a kernel thread) */
if (usp) {
usp = ALIGN(usp, 4);
if (likely(usp))
cregs->gr[30] = usp;
}
cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
cregs->kpc = (unsigned long) &child_return;
/* Setup thread TLS area from the 4th parameter in clone */
if (clone_flags & CLONE_SETTLS)
cregs->cr27 = cregs->gr[23];
}
return 0;
}
static inline int valid_stack_ptr(struct task_struct *task,
void *p, unsigned int size, void *end)
{
void *t = task_stack_page(task);
if (end) {
if (p < end && p >= (end-THREAD_SIZE))
return 1;
else
return 0;
}
return p >= t && p < t + THREAD_SIZE - size;
}
/* Test that VMAP_STACK is actually allocating with a leading guard page */
void lkdtm_STACK_GUARD_PAGE_LEADING(void)
{
const unsigned char *stack = task_stack_page(current);
const unsigned char *ptr = stack - 1;
volatile unsigned char byte;
pr_info("attempting bad read from page below current stack\n");
byte = *ptr;
pr_err("FAIL: accessed page before stack!\n");
}
/* Test that VMAP_STACK is actually allocating with a trailing guard page */
void lkdtm_STACK_GUARD_PAGE_TRAILING(void)
{
const unsigned char *stack = task_stack_page(current);
const unsigned char *ptr = stack + THREAD_SIZE;
volatile unsigned char byte;
pr_info("attempting bad read from page above current stack\n");
byte = *ptr;
pr_err("FAIL: accessed page after stack!\n");
}
/*
* set up the kernel stack for a new thread and copy arch-specific thread
* control information
*/
int copy_thread(unsigned long clone_flags,
unsigned long c_usp, unsigned long ustk_size,
struct task_struct *p, struct pt_regs *kregs)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *c_uregs, *c_kregs, *uregs;
unsigned long c_ksp;
uregs = current->thread.uregs;
c_ksp = (unsigned long) task_stack_page(p) + THREAD_SIZE;
/* allocate the userspace exception frame and set it up */
c_ksp -= sizeof(struct pt_regs);
c_uregs = (struct pt_regs *) c_ksp;
p->thread.uregs = c_uregs;
*c_uregs = *uregs;
c_uregs->sp = c_usp;
c_uregs->epsw &= ~EPSW_FE; /* my FPU */
c_ksp -= 12; /* allocate function call ABI slack */
/* the new TLS pointer is passed in as arg #5 to sys_clone() */
if (clone_flags & CLONE_SETTLS)
c_uregs->e2 = current_frame()->d3;
/* set up the return kernel frame if called from kernel_thread() */
c_kregs = c_uregs;
if (kregs != uregs) {
c_ksp -= sizeof(struct pt_regs);
c_kregs = (struct pt_regs *) c_ksp;
*c_kregs = *kregs;
c_kregs->sp = c_usp;
c_kregs->next = c_uregs;
#ifdef CONFIG_MN10300_CURRENT_IN_E2
c_kregs->e2 = (unsigned long) p; /* current */
#endif
c_ksp -= 12; /* allocate function call ABI slack */
}
/* set up things up so the scheduler can start the new task */
ti->frame = c_kregs;
p->thread.a3 = (unsigned long) c_kregs;
p->thread.sp = c_ksp;
p->thread.pc = (unsigned long) ret_from_fork;
p->thread.wchan = (unsigned long) ret_from_fork;
p->thread.usp = c_usp;
return 0;
}