traps.c

一个2.4.21版本的嵌入式linux内核

/*
 *  linux/arch/parisc/traps.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 1999, 2000  Philipp Rumpf <[e-mail]>
 */

/*
 * 'Traps.c' handles hardware traps and faults after we have saved some
 * state in 'asm.s'.
 */

#include <linux/config.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/console.h>

#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/traps.h>
#include <asm/unaligned.h>
#include <asm/atomic.h>
#include <asm/smp.h>
#include <asm/pdc.h>
#include <asm/pdc_chassis.h>

#include "../math-emu/math-emu.h"	/* for handle_fpe() */

#define PRINT_USER_FAULTS /* (turn this on if you want user faults to be */
			  /*  dumped to the console via printk)          */

static int printbinary(char *buf, unsigned long x, int nbits)
{
	unsigned long mask = 1UL << (nbits - 1);
	while (mask != 0) {
		*buf++ = (mask & x ? '1' : '0');
		mask >>= 1;
	}
	*buf = '\0';

	return nbits;
}

#ifdef __LP64__
#define RFMT "%016lx"
#else
#define RFMT "%08lx"
#endif

static int kstack_depth_to_print = 24;
extern struct module *module_list;
extern struct module kernel_module;

static inline int kernel_text_address(unsigned long addr)
{
#ifdef CONFIG_MODULES
	int retval = 0;
	struct module *mod;
#endif
	extern char _stext, _etext;

	if (addr >= (unsigned long) &_stext &&
	    addr <= (unsigned long) &_etext)
		return 1;

#ifdef CONFIG_MODULES
	for (mod = module_list; mod != &kernel_module; mod = mod->next) {
		/* mod_bound tests for addr being inside the vmalloc'ed
		 * module area. Of course it'd be better to test only
		 * for the .text subset... */
		if (mod_bound(addr, 0, mod)) {
			retval = 1;
			break;
		}
	}
	return retval;
#endif
}


void show_trace(unsigned long * stack)
{
	unsigned long *startstack;
	unsigned long addr;
	int i;

	startstack = (unsigned long *)((unsigned long)stack & ~(THREAD_SIZE - 1));
	i = 1;
	printk("Kernel addresses on the stack:\n");
	while (stack >= startstack) {
		addr = *stack--;
		if (kernel_text_address(addr)) {
			printk(" [<" RFMT ">] ", addr);
			if ((i & 0x03) == 0)
				printk("\n");
			i++;
		}
	}
	printk("\n");
}

void show_trace_task(struct task_struct *tsk)
{
	show_trace((unsigned long *)tsk->thread.regs.ksp);
}

void show_stack(unsigned long * sp)
{
	unsigned long *stack;
	int i;

	/*
	 * debugging aid: "show_stack(NULL);" prints the
	 * back trace for this cpu.
	 */
	if (sp==NULL)
		sp = (unsigned long*)&sp;

	stack = sp;
	printk("\n" KERN_CRIT "Stack Dump:\n");
	printk(KERN_CRIT " " RFMT ":  ", (unsigned long) stack);
	for (i=0; i < kstack_depth_to_print; i++) {
		if (((long) stack & (THREAD_SIZE-1)) == 0)
			break;
		if (i && ((i & 0x03) == 0))
			printk("\n" KERN_CRIT " " RFMT ":  ",
				(unsigned long) stack);
		printk(RFMT " ", *stack--);
	}
	printk("\n" KERN_CRIT "\n");
	show_trace(sp);
}

/*
 * The architecture-independent backtrace generator
 */
void dump_stack(void)
{
	show_stack(0);
}


void show_regs(struct pt_regs *regs)
{
	int i;
	char buf[128], *p;
	char *level;
	unsigned long cr30;
	unsigned long cr31;

	level = user_mode(regs) ? KERN_DEBUG : KERN_CRIT;

	printk("%s\n", level); /* don't want to have that pretty register dump messed up */

	printk("%s     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI\n", level);
	printbinary(buf, regs->gr[0], 32);
	printk("%sPSW: %s %s\n", level, buf, print_tainted());

	for (i = 0; i < 32; i += 4) {
		int j;
		p = buf;
		p += sprintf(p, "%sr%02d-%02d ", level, i, i + 3);
		for (j = 0; j < 4; j++) {
			p += sprintf(p, " " RFMT, (i+j) == 0 ? 0 : regs->gr[i + j]);
		}
		printk("%s\n", buf);
	}

	for (i = 0; i < 8; i += 4) {
		int j;
		p = buf;
		p += sprintf(p, "%ssr%d-%d  ", level, i, i + 3);
		for (j = 0; j < 4; j++) {
			p += sprintf(p, " " RFMT, regs->sr[i + j]);
		}
		printk("%s\n", buf);
	}

#if RIDICULOUSLY_VERBOSE
	for (i = 0; i < 32; i += 2)
		printk("%sFR%02d : %016lx  FR%2d : %016lx", level, i,
				regs->fr[i], i+1, regs->fr[i+1]);
#endif

	cr30 = mfctl(30);
	cr31 = mfctl(31);
	printk("%s\n", level);
	printk("%sIASQ: " RFMT " " RFMT " IAOQ: " RFMT " " RFMT "\n",
	       level, regs->iasq[0], regs->iasq[1], regs->iaoq[0], regs->iaoq[1]);
	printk("%s IIR: %08lx    ISR: " RFMT "  IOR: " RFMT "\n",
	       level, regs->iir, regs->isr, regs->ior);
	printk("%s CPU: %8d   CR30: " RFMT " CR31: " RFMT "\n",
	       level, ((struct task_struct *)cr30)->processor, cr30, cr31);
	printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28);
}


void die_if_kernel(char *str, struct pt_regs *regs, long err)
{
	if (user_mode(regs)) {
#ifdef PRINT_USER_FAULTS
		if (err == 0)
			return; /* STFU */

		/* XXX for debugging only */
		printk(KERN_DEBUG "%s (pid %d): %s (code %ld)\n",
			current->comm, current->pid, str, err);
		show_regs(regs);
#endif
		return;
	}
	
	/* unlock the pdc lock if necessary */
	pdc_emergency_unlock();

	/* maybe the kernel hasn't booted very far yet and hasn't been able 
	 * to initialize the serial or STI console. In that case we should 
	 * re-enable the pdc console, so that the user will be able to 
	 * identify the problem. */
	if (!console_drivers)
		pdc_console_restart();
	
	printk(KERN_CRIT "%s (pid %d): %s (code %ld)\n",
		current->comm, current->pid, str, err);
	show_regs(regs);

	/* Wot's wrong wif bein' racy? */
	if (current->thread.flags & PARISC_KERNEL_DEATH) {
		printk(KERN_CRIT "%s() recursion detected.\n", __FUNCTION__);
		sti();
		while (1);
	}

	current->thread.flags |= PARISC_KERNEL_DEATH;
	do_exit(SIGSEGV);
}

int syscall_ipi(int (*syscall) (struct pt_regs *), struct pt_regs *regs)
{
	return syscall(regs);
}

/* gdb uses break 4,8 */
#define GDB_BREAK_INSN 0x10004
void handle_gdb_break(struct pt_regs *regs, int wot)
{
	struct siginfo si;

	si.si_code = wot;
	si.si_addr = (void *) (regs->iaoq[0] & ~3);
	si.si_signo = SIGTRAP;
	si.si_errno = 0;
	force_sig_info(SIGTRAP, &si, current);
}

void handle_break(unsigned iir, struct pt_regs *regs)
{
	struct siginfo si;

	switch(iir) {
	case 0x00:
#ifdef PRINT_USER_FAULTS
		printk(KERN_DEBUG "break 0,0: pid=%d command='%s'\n",
		       current->pid, current->comm);
#endif
		die_if_kernel("Breakpoint", regs, 0);
#ifdef PRINT_USER_FAULTS
		show_regs(regs);
#endif
		si.si_code = TRAP_BRKPT;
		si.si_addr = (void *) (regs->iaoq[0] & ~3);
		si.si_signo = SIGTRAP;
		force_sig_info(SIGTRAP, &si, current);
		break;

	case GDB_BREAK_INSN:
		die_if_kernel("Breakpoint", regs, 0);
		handle_gdb_break(regs, TRAP_BRKPT);
		break;

	default:
#ifdef PRINT_USER_FAULTS
		printk(KERN_DEBUG "break %#08x: pid=%d command='%s'\n",
		       iir, current->pid, current->comm);
		show_regs(regs);
#endif
		si.si_signo = SIGTRAP;
		si.si_code = TRAP_BRKPT;
		si.si_addr = (void *) (regs->iaoq[0] & ~3);
		force_sig_info(SIGTRAP, &si, current);
		return;
	}
}


int handle_toc(void)
{
	printk(KERN_CRIT "TOC call.\n");
	return 0;
}

static void default_trap(int code, struct pt_regs *regs)
{
	printk(KERN_ERR "Trap %d on CPU %d\n", code, smp_processor_id());
	show_regs(regs);
}

void (*cpu_lpmc) (int code, struct pt_regs *regs) = default_trap;


void transfer_pim_to_trap_frame(struct pt_regs *regs)
{
    register int i;
    extern unsigned int hpmc_pim_data[];
    struct pdc_hpmc_pim_11 *pim_narrow;
    struct pdc_hpmc_pim_20 *pim_wide;

    if (boot_cpu_data.cpu_type >= pcxu) {

	pim_wide = (struct pdc_hpmc_pim_20 *)hpmc_pim_data;

	/*
	 * Note: The following code will probably generate a
	 * bunch of truncation error warnings from the compiler.
	 * Could be handled with an ifdef, but perhaps there
	 * is a better way.
	 */

	regs->gr[0] = pim_wide->cr[22];

	for (i = 1; i < 32; i++)
	    regs->gr[i] = pim_wide->gr[i];

	for (i = 0; i < 32; i++)
	    regs->fr[i] = pim_wide->fr[i];

	for (i = 0; i < 8; i++)
	    regs->sr[i] = pim_wide->sr[i];

	regs->iasq[0] = pim_wide->cr[17];
	regs->iasq[1] = pim_wide->iasq_back;
	regs->iaoq[0] = pim_wide->cr[18];
	regs->iaoq[1] = pim_wide->iaoq_back;

	regs->sar  = pim_wide->cr[11];
	regs->iir  = pim_wide->cr[19];
	regs->isr  = pim_wide->cr[20];
	regs->ior  = pim_wide->cr[21];
    }
    else {
	pim_narrow = (struct pdc_hpmc_pim_11 *)hpmc_pim_data;

	regs->gr[0] = pim_narrow->cr[22];

	for (i = 1; i < 32; i++)
	    regs->gr[i] = pim_narrow->gr[i];

	for (i = 0; i < 32; i++)
	    regs->fr[i] = pim_narrow->fr[i];

	for (i = 0; i < 8; i++)
	    regs->sr[i] = pim_narrow->sr[i];

	regs->iasq[0] = pim_narrow->cr[17];
	regs->iasq[1] = pim_narrow->iasq_back;
	regs->iaoq[0] = pim_narrow->cr[18];
	regs->iaoq[1] = pim_narrow->iaoq_back;

	regs->sar  = pim_narrow->cr[11];
	regs->iir  = pim_narrow->cr[19];
	regs->isr  = pim_narrow->cr[20];
	regs->ior  = pim_narrow->cr[21];
    }

    /*
     * The following fields only have meaning if we came through
     * another path. So just zero them here.
     */

    regs->ksp = 0;
    regs->kpc = 0;
    regs->orig_r28 = 0;
}