/* * 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/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_stop_sched_tick(1); while (!need_resched()) cpu_idle_sleep(); tick_nohz_restart_sched_tick(); 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, unsigned long parent_tidptr, unsigned long child_tidptr, struct pt_regs *regs) { if (!newsp) newsp = regs->sp; return do_fork(clone_flags, newsp, regs, 0, (int __user *)parent_tidptr, (int __user *)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(char __user *ufilename, char __user *__user *uargv, char __user *__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; }