- 根目录:
- arch
- avr32
- kernel
- process.c
/*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/fs.h>
#include <linux/pm.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/reboot.h>
#include <linux/tick.h>
#include <linux/uaccess.h>
#include <linux/unistd.h>
#include <asm/sysreg.h>
#include <asm/ocd.h>
#include <asm/syscalls.h>
#include <mach/pm.h>
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);
/*
* This file handles the architecture-dependent parts of process handling..
*/
void cpu_idle(void)
{
/* endless idle loop with no priority at all */
while (1) {
tick_nohz_idle_enter();
rcu_idle_enter();
while (!need_resched())
cpu_idle_sleep();
rcu_idle_exit();
tick_nohz_idle_exit();
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
void machine_halt(void)
{
/*
* Enter Stop mode. The 32 kHz oscillator will keep running so
* the RTC will keep the time properly and the system will
* boot quickly.
*/
asm volatile("sleep 3\n\t"
"sub pc, -2");
}
void machine_power_off(void)
{
if (pm_power_off)
pm_power_off();
}
void machine_restart(char *cmd)
{
ocd_write(DC, (1 << OCD_DC_DBE_BIT));
ocd_write(DC, (1 << OCD_DC_RES_BIT));
while (1) ;
}
/*
* PC is actually discarded when returning from a system call -- the
* return address must be stored in LR. This function will make sure
* LR points to do_exit before starting the thread.
*
* Also, when returning from fork(), r12 is 0, so we must copy the
* argument as well.
*
* r0 : The argument to the main thread function
* r1 : The address of do_exit
* r2 : The address of the main thread function
*/
asmlinkage extern void kernel_thread_helper(void);
__asm__(" .type kernel_thread_helper, @function\n"
"kernel_thread_helper:\n"
" mov r12, r0\n"
" mov lr, r2\n"
" mov pc, r1\n"
" .size kernel_thread_helper, . - kernel_thread_helper");
int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
struct pt_regs regs;
memset(®s, 0, sizeof(regs));
regs.r0 = (unsigned long)arg;
regs.r1 = (unsigned long)fn;
regs.r2 = (unsigned long)do_exit;
regs.lr = (unsigned long)kernel_thread_helper;
regs.pc = (unsigned long)kernel_thread_helper;
regs.sr = MODE_SUPERVISOR;
return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
0, ®s, 0, NULL, NULL);
}
EXPORT_SYMBOL(kernel_thread);
/*
* Free current thread data structures etc
*/
void exit_thread(void)
{
ocd_disable(current);
}
void flush_thread(void)
{
/* nothing to do */
}
void release_thread(struct task_struct *dead_task)
{
/* do nothing */
}
static void dump_mem(const char *str, const char *log_lvl,
unsigned long bottom, unsigned long top)
{
unsigned long p;
int i;
printk("%s%s(0x%08lx to 0x%08lx)\n", log_lvl, str, bottom, top);
for (p = bottom & ~31; p < top; ) {
printk("%s%04lx: ", log_lvl, p & 0xffff);
for (i = 0; i < 8; i++, p += 4) {
unsigned int val;
if (p < bottom || p >= top)
printk(" ");
else {
if (__get_user(val, (unsigned int __user *)p)) {
printk("\n");
goto out;
}
printk("%08x ", val);
}
}
printk("\n");
}
out:
return;
}
static inline int valid_stack_ptr(struct thread_info *tinfo, unsigned long p)
{
return (p > (unsigned long)tinfo)
&& (p < (unsigned long)tinfo + THREAD_SIZE - 3);
}
#ifdef CONFIG_FRAME_POINTER
static void show_trace_log_lvl(struct task_struct *tsk, unsigned long *sp,
struct pt_regs *regs, const char *log_lvl)
{
unsigned long lr, fp;
struct thread_info *tinfo;
if (regs)
fp = regs->r7;
else if (tsk == current)
asm("mov %0, r7" : "=r"(fp));
else
fp = tsk->thread.cpu_context.r7;
/*
* Walk the stack as long as the frame pointer (a) is within
* the kernel stack of the task, and (b) it doesn't move
* downwards.
*/
tinfo = task_thread_info(tsk);
printk("%sCall trace:\n", log_lvl);
while (valid_stack_ptr(tinfo, fp)) {
unsigned long new_fp;
lr = *(unsigned long *)fp;
#ifdef CONFIG_KALLSYMS
printk("%s [<%08lx>] ", log_lvl, lr);
#else
printk(" [<%08lx>] ", lr);
#endif
print_symbol("%s\n", lr);
new_fp = *(unsigned long *)(fp + 4);
if (new_fp <= fp)
break;
fp = new_fp;
}
printk("\n");
}
#else
static void show_trace_log_lvl(struct task_struct *tsk, unsigned long *sp,
struct pt_regs *regs, const char *log_lvl)
{
unsigned long addr;
printk("%sCall trace:\n", log_lvl);
while (!kstack_end(sp)) {
addr = *sp++;
if (kernel_text_address(addr)) {
#ifdef CONFIG_KALLSYMS
printk("%s [<%08lx>] ", log_lvl, addr);
#else
printk(" [<%08lx>] ", addr);
#endif
print_symbol("%s\n", addr);
}
}
printk("\n");
}
#endif
void show_stack_log_lvl(struct task_struct *tsk, unsigned long sp,
struct pt_regs *regs, const char *log_lvl)
{
struct thread_info *tinfo;
if (sp == 0) {
if (tsk)
sp = tsk->thread.cpu_context.ksp;
else
sp = (unsigned long)&tinfo;
}
if (!tsk)
tsk = current;
tinfo = task_thread_info(tsk);
if (valid_stack_ptr(tinfo, sp)) {
dump_mem("Stack: ", log_lvl, sp,
THREAD_SIZE + (unsigned long)tinfo);
show_trace_log_lvl(tsk, (unsigned long *)sp, regs, log_lvl);
}
}
void show_stack(struct task_struct *tsk, unsigned long *stack)
{
show_stack_log_lvl(tsk, (unsigned long)stack, NULL, "");
}
void dump_stack(void)
{
unsigned long stack;
show_trace_log_lvl(current, &stack, NULL, "");
}
EXPORT_SYMBOL(dump_stack);
static const char *cpu_modes[] = {
"Application", "Supervisor", "Interrupt level 0", "Interrupt level 1",
"Interrupt level 2", "Interrupt level 3", "Exception", "NMI"
};
void show_regs_log_lvl(struct pt_regs *regs, const char *log_lvl)
{
unsigned long sp = regs->sp;
unsigned long lr = regs->lr;
unsigned long mode = (regs->sr & MODE_MASK) >> MODE_SHIFT;
if (!user_mode(regs)) {
sp = (unsigned long)regs + FRAME_SIZE_FULL;
printk("%s", log_lvl);
print_symbol("PC is at %s\n", instruction_pointer(regs));
printk("%s", log_lvl);
print_symbol("LR is at %s\n", lr);
}
printk("%spc : [<%08lx>] lr : [<%08lx>] %s\n"
"%ssp : %08lx r12: %08lx r11: %08lx\n",
log_lvl, instruction_pointer(regs), lr, print_tainted(),
log_lvl, sp, regs->r12, regs->r11);
printk("%sr10: %08lx r9 : %08lx r8 : %08lx\n",
log_lvl, regs->r10, regs->r9, regs->r8);
printk("%sr7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
log_lvl, regs->r7, regs->r6, regs->r5, regs->r4);
printk("%sr3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
log_lvl, regs->r3, regs->r2, regs->r1, regs->r0);
printk("%sFlags: %c%c%c%c%c\n", log_lvl,
regs->sr & SR_Q ? 'Q' : 'q',
regs->sr & SR_V ? 'V' : 'v',
regs->sr & SR_N ? 'N' : 'n',
regs->sr & SR_Z ? 'Z' : 'z',
regs->sr & SR_C ? 'C' : 'c');
printk("%sMode bits: %c%c%c%c%c%c%c%c%c%c\n", log_lvl,
regs->sr & SR_H ? 'H' : 'h',
regs->sr & SR_J ? 'J' : 'j',
regs->sr & SR_DM ? 'M' : 'm',
regs->sr & SR_D ? 'D' : 'd',
regs->sr & SR_EM ? 'E' : 'e',
regs->sr & SR_I3M ? '3' : '.',
regs->sr & SR_I2M ? '2' : '.',
regs->sr & SR_I1M ? '1' : '.',
regs->sr & SR_I0M ? '0' : '.',
regs->sr & SR_GM ? 'G' : 'g');
printk("%sCPU Mode: %s\n", log_lvl, cpu_modes[mode]);
printk("%sProcess: %s [%d] (task: %p thread: %p)\n",
log_lvl, current->comm, current->pid, current,
task_thread_info(current));
}
void show_regs(struct pt_regs *regs)
{
unsigned long sp = regs->sp;
if (!user_mode(regs))
sp = (unsigned long)regs + FRAME_SIZE_FULL;
show_regs_log_lvl(regs, "");
show_trace_log_lvl(current, (unsigned long *)sp, regs, "");
}
EXPORT_SYMBOL(show_regs);
/* Fill in the fpu structure for a core dump. This is easy -- we don't have any */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
{
/* Not valid */
return 0;
}
asmlinkage void ret_from_fork(void);
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;
childregs = ((struct pt_regs *)(THREAD_SIZE + (unsigned long)task_stack_page(p))) - 1;
*childregs = *regs;
if (user_mode(regs))
childregs->sp = usp;
else
childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
childregs->r12 = 0; /* Set return value for child */
p->thread.cpu_context.sr = MODE_SUPERVISOR | SR_GM;
p->thread.cpu_context.ksp = (unsigned long)childregs;
p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
clear_tsk_thread_flag(p, TIF_DEBUG);
if ((clone_flags & CLONE_PTRACE) && test_thread_flag(TIF_DEBUG))
ocd_enable(p);
return 0;
}
/* r12-r8 are dummy parameters to force the compiler to use the stack */
asmlinkage int sys_fork(struct pt_regs *regs)
{
return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
}
asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
void __user *parent_tidptr, void __user *child_tidptr,
struct pt_regs *regs)
{
if (!newsp)
newsp = regs->sp;
return do_fork(clone_flags, newsp, regs, 0, parent_tidptr,
child_tidptr);
}
asmlinkage int sys_vfork(struct pt_regs *regs)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs,
0, NULL, NULL);
}
asmlinkage int sys_execve(const char __user *ufilename,
const char __user *const __user *uargv,
const char __user *const __user *uenvp,
struct pt_regs *regs)
{
int error;
char *filename;
filename = getname(ufilename);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename, uargv, uenvp, regs);
putname(filename);
out:
return error;
}
/*
* This function is supposed to answer the question "who called
* schedule()?"
*/
unsigned long get_wchan(struct task_struct *p)
{
unsigned long pc;
unsigned long stack_page;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_page = (unsigned long)task_stack_page(p);
BUG_ON(!stack_page);
/*
* The stored value of PC is either the address right after
* the call to __switch_to() or ret_from_fork.
*/
pc = thread_saved_pc(p);
if (in_sched_functions(pc)) {
#ifdef CONFIG_FRAME_POINTER
unsigned long fp = p->thread.cpu_context.r7;
BUG_ON(fp < stack_page || fp > (THREAD_SIZE + stack_page));
pc = *(unsigned long *)fp;
#else
/*
* We depend on the frame size of schedule here, which
* is actually quite ugly. It might be possible to
* determine the frame size automatically at build
* time by doing this:
* - compile sched.c
* - disassemble the resulting sched.o
* - look for 'sub sp,??' shortly after '<schedule>:'
*/
unsigned long sp = p->thread.cpu_context.ksp + 16;
BUG_ON(sp < stack_page || sp > (THREAD_SIZE + stack_page));
pc = *(unsigned long *)sp;
#endif
}
return pc;
}