traps.c - Android社区 - https://www.androidos.net.cn/

Kernel | 2.6.39

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/* traps.c: high-level exception handler for FR-V
 *
 * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/types.h>
#include <linux/user.h>
#include <linux/string.h>
#include <linux/linkage.h>
#include <linux/init.h>
#include <linux/module.h>

#include <asm/asm-offsets.h>
#include <asm/setup.h>
#include <asm/fpu.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/siginfo.h>
#include <asm/unaligned.h>

void show_backtrace(struct pt_regs *, unsigned long);

extern asmlinkage void __break_hijack_kernel_event(void);

/*****************************************************************************/
/*
 * instruction access error
 */
asmlinkage void insn_access_error(unsigned long esfr1, unsigned long epcr0, unsigned long esr0)
{
	siginfo_t info;

die_if_kernel("-- Insn Access Error --\n"
		      "EPCR0 : %08lx\n"
		      "ESR0  : %08lx\n",
		      epcr0, esr0);

info.si_signo	= SIGSEGV;
	info.si_code	= SEGV_ACCERR;
	info.si_errno	= 0;
	info.si_addr	= (void __user *) ((epcr0 & EPCR0_V) ? (epcr0 & EPCR0_PC) : __frame->pc);

force_sig_info(info.si_signo, &info, current);
} /* end insn_access_error() */

/*****************************************************************************/
/*
 * handler for:
 * - illegal instruction
 * - privileged instruction
 * - unsupported trap
 * - debug exceptions
 */
asmlinkage void illegal_instruction(unsigned long esfr1, unsigned long epcr0, unsigned long esr0)
{
	siginfo_t info;

die_if_kernel("-- Illegal Instruction --\n"
		      "EPCR0 : %08lx\n"
		      "ESR0  : %08lx\n"
		      "ESFR1 : %08lx\n",
		      epcr0, esr0, esfr1);

info.si_errno	= 0;
	info.si_addr	= (void __user *) ((epcr0 & EPCR0_V) ? (epcr0 & EPCR0_PC) : __frame->pc);

switch (__frame->tbr & TBR_TT) {
	case TBR_TT_ILLEGAL_INSTR:
		info.si_signo	= SIGILL;
		info.si_code	= ILL_ILLOPC;
		break;
	case TBR_TT_PRIV_INSTR:
		info.si_signo	= SIGILL;
		info.si_code	= ILL_PRVOPC;
		break;
	case TBR_TT_TRAP2 ... TBR_TT_TRAP126:
		info.si_signo	= SIGILL;
		info.si_code	= ILL_ILLTRP;
		break;
	/* GDB uses "tira gr0, #1" as a breakpoint instruction.  */
	case TBR_TT_TRAP1:
	case TBR_TT_BREAK:
		info.si_signo	= SIGTRAP;
		info.si_code	=
			(__frame->__status & REG__STATUS_STEPPED) ? TRAP_TRACE : TRAP_BRKPT;
		break;
	}

force_sig_info(info.si_signo, &info, current);
} /* end illegal_instruction() */

/*****************************************************************************/
/*
 * handle atomic operations with errors
 * - arguments in gr8, gr9, gr10
 * - original memory value placed in gr5
 * - replacement memory value placed in gr9
 */
asmlinkage void atomic_operation(unsigned long esfr1, unsigned long epcr0,
				 unsigned long esr0)
{
	static DEFINE_SPINLOCK(atomic_op_lock);
	unsigned long x, y, z;
	unsigned long __user *p;
	mm_segment_t oldfs;
	siginfo_t info;
	int ret;

y = 0;
	z = 0;

oldfs = get_fs();
	if (!user_mode(__frame))
		set_fs(KERNEL_DS);

switch (__frame->tbr & TBR_TT) {
		/* TIRA gr0,#120
		 * u32 __atomic_user_cmpxchg32(u32 *ptr, u32 test, u32 new)
		 */
	case TBR_TT_ATOMIC_CMPXCHG32:
		p = (unsigned long __user *) __frame->gr8;
		x = __frame->gr9;
		y = __frame->gr10;

for (;;) {
			ret = get_user(z, p);
			if (ret < 0)
				goto error;

if (z != x)
				goto done;