cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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exceptions.c (4073B)


      1/*
      2 * HW exception handling
      3 *
      4 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
      5 * Copyright (C) 2008 PetaLogix
      6 *
      7 * This file is subject to the terms and conditions of the GNU General
      8 * Public License.  See the file COPYING in the main directory of this
      9 * archive for more details.
     10 */
     11
     12/*
     13 * This file handles the architecture-dependent parts of hardware exceptions
     14 */
     15
     16#include <linux/export.h>
     17#include <linux/kernel.h>
     18#include <linux/signal.h>
     19#include <linux/sched.h>
     20#include <linux/sched/debug.h>
     21#include <linux/kallsyms.h>
     22
     23#include <asm/exceptions.h>
     24#include <asm/entry.h>		/* For KM CPU var */
     25#include <linux/uaccess.h>
     26#include <linux/errno.h>
     27#include <linux/ptrace.h>
     28#include <asm/current.h>
     29#include <asm/cacheflush.h>
     30
     31#define MICROBLAZE_ILL_OPCODE_EXCEPTION	0x02
     32#define MICROBLAZE_IBUS_EXCEPTION	0x03
     33#define MICROBLAZE_DBUS_EXCEPTION	0x04
     34#define MICROBLAZE_DIV_ZERO_EXCEPTION	0x05
     35#define MICROBLAZE_FPU_EXCEPTION	0x06
     36#define MICROBLAZE_PRIVILEGED_EXCEPTION	0x07
     37
     38static DEFINE_SPINLOCK(die_lock);
     39
     40void die(const char *str, struct pt_regs *fp, long err)
     41{
     42	console_verbose();
     43	spin_lock_irq(&die_lock);
     44	pr_warn("Oops: %s, sig: %ld\n", str, err);
     45	show_regs(fp);
     46	spin_unlock_irq(&die_lock);
     47	/* make_task_dead() should take care of panic'ing from an interrupt
     48	 * context so we don't handle it here
     49	 */
     50	make_task_dead(err);
     51}
     52
     53/* for user application debugging */
     54asmlinkage void sw_exception(struct pt_regs *regs)
     55{
     56	_exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16);
     57	flush_dcache_range(regs->r16, regs->r16 + 0x4);
     58	flush_icache_range(regs->r16, regs->r16 + 0x4);
     59}
     60
     61void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
     62{
     63	if (kernel_mode(regs))
     64		die("Exception in kernel mode", regs, signr);
     65
     66	force_sig_fault(signr, code, (void __user *)addr);
     67}
     68
     69asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
     70							int fsr, int addr)
     71{
     72	addr = regs->pc;
     73
     74#if 0
     75	pr_warn("Exception %02x in %s mode, FSR=%08x PC=%08x ESR=%08x\n",
     76			type, user_mode(regs) ? "user" : "kernel", fsr,
     77			(unsigned int) regs->pc, (unsigned int) regs->esr);
     78#endif
     79
     80	switch (type & 0x1F) {
     81	case MICROBLAZE_ILL_OPCODE_EXCEPTION:
     82		if (user_mode(regs)) {
     83			pr_debug("Illegal opcode exception in user mode\n");
     84			_exception(SIGILL, regs, ILL_ILLOPC, addr);
     85			return;
     86		}
     87		pr_warn("Illegal opcode exception in kernel mode.\n");
     88		die("opcode exception", regs, SIGBUS);
     89		break;
     90	case MICROBLAZE_IBUS_EXCEPTION:
     91		if (user_mode(regs)) {
     92			pr_debug("Instruction bus error exception in user mode\n");
     93			_exception(SIGBUS, regs, BUS_ADRERR, addr);
     94			return;
     95		}
     96		pr_warn("Instruction bus error exception in kernel mode.\n");
     97		die("bus exception", regs, SIGBUS);
     98		break;
     99	case MICROBLAZE_DBUS_EXCEPTION:
    100		if (user_mode(regs)) {
    101			pr_debug("Data bus error exception in user mode\n");
    102			_exception(SIGBUS, regs, BUS_ADRERR, addr);
    103			return;
    104		}
    105		pr_warn("Data bus error exception in kernel mode.\n");
    106		die("bus exception", regs, SIGBUS);
    107		break;
    108	case MICROBLAZE_DIV_ZERO_EXCEPTION:
    109		if (user_mode(regs)) {
    110			pr_debug("Divide by zero exception in user mode\n");
    111			_exception(SIGFPE, regs, FPE_INTDIV, addr);
    112			return;
    113		}
    114		pr_warn("Divide by zero exception in kernel mode.\n");
    115		die("Divide by zero exception", regs, SIGBUS);
    116		break;
    117	case MICROBLAZE_FPU_EXCEPTION:
    118		pr_debug("FPU exception\n");
    119		/* IEEE FP exception */
    120		/* I removed fsr variable and use code var for storing fsr */
    121		if (fsr & FSR_IO)
    122			fsr = FPE_FLTINV;
    123		else if (fsr & FSR_OF)
    124			fsr = FPE_FLTOVF;
    125		else if (fsr & FSR_UF)
    126			fsr = FPE_FLTUND;
    127		else if (fsr & FSR_DZ)
    128			fsr = FPE_FLTDIV;
    129		else if (fsr & FSR_DO)
    130			fsr = FPE_FLTRES;
    131		_exception(SIGFPE, regs, fsr, addr);
    132		break;
    133	case MICROBLAZE_PRIVILEGED_EXCEPTION:
    134		pr_debug("Privileged exception\n");
    135		_exception(SIGILL, regs, ILL_PRVOPC, addr);
    136		break;
    137	default:
    138	/* FIXME what to do in unexpected exception */
    139		pr_warn("Unexpected exception %02x PC=%08x in %s mode\n",
    140			type, (unsigned int) addr,
    141			kernel_mode(regs) ? "kernel" : "user");
    142	}
    143	return;
    144}