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0e25498f8c
There are two big uses of do_exit. The first is it's design use to be the guts of the exit(2) system call. The second use is to terminate a task after something catastrophic has happened like a NULL pointer in kernel code. Add a function make_task_dead that is initialy exactly the same as do_exit to cover the cases where do_exit is called to handle catastrophic failure. In time this can probably be reduced to just a light wrapper around do_task_dead. For now keep it exactly the same so that there will be no behavioral differences introducing this new concept. Replace all of the uses of do_exit that use it for catastraphic task cleanup with make_task_dead to make it clear what the code is doing. As part of this rename rewind_stack_do_exit rewind_stack_and_make_dead. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
144 lines
4 KiB
C
144 lines
4 KiB
C
/*
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* HW exception handling
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*
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* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
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* Copyright (C) 2008 PetaLogix
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*
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* This file is subject to the terms and conditions of the GNU General
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* Public License. See the file COPYING in the main directory of this
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* archive for more details.
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*/
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/*
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* This file handles the architecture-dependent parts of hardware exceptions
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*/
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#include <linux/export.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/sched/debug.h>
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#include <linux/kallsyms.h>
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#include <asm/exceptions.h>
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#include <asm/entry.h> /* For KM CPU var */
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#include <linux/uaccess.h>
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#include <linux/errno.h>
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#include <linux/ptrace.h>
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#include <asm/current.h>
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#include <asm/cacheflush.h>
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#define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02
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#define MICROBLAZE_IBUS_EXCEPTION 0x03
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#define MICROBLAZE_DBUS_EXCEPTION 0x04
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#define MICROBLAZE_DIV_ZERO_EXCEPTION 0x05
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#define MICROBLAZE_FPU_EXCEPTION 0x06
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#define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07
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static DEFINE_SPINLOCK(die_lock);
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void die(const char *str, struct pt_regs *fp, long err)
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{
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console_verbose();
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spin_lock_irq(&die_lock);
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pr_warn("Oops: %s, sig: %ld\n", str, err);
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show_regs(fp);
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spin_unlock_irq(&die_lock);
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/* make_task_dead() should take care of panic'ing from an interrupt
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* context so we don't handle it here
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*/
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make_task_dead(err);
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}
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/* for user application debugging */
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asmlinkage void sw_exception(struct pt_regs *regs)
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{
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_exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16);
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flush_dcache_range(regs->r16, regs->r16 + 0x4);
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flush_icache_range(regs->r16, regs->r16 + 0x4);
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}
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void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
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{
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if (kernel_mode(regs))
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die("Exception in kernel mode", regs, signr);
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force_sig_fault(signr, code, (void __user *)addr);
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}
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asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
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int fsr, int addr)
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{
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addr = regs->pc;
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#if 0
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pr_warn("Exception %02x in %s mode, FSR=%08x PC=%08x ESR=%08x\n",
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type, user_mode(regs) ? "user" : "kernel", fsr,
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(unsigned int) regs->pc, (unsigned int) regs->esr);
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#endif
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switch (type & 0x1F) {
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case MICROBLAZE_ILL_OPCODE_EXCEPTION:
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if (user_mode(regs)) {
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pr_debug("Illegal opcode exception in user mode\n");
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_exception(SIGILL, regs, ILL_ILLOPC, addr);
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return;
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}
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pr_warn("Illegal opcode exception in kernel mode.\n");
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die("opcode exception", regs, SIGBUS);
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break;
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case MICROBLAZE_IBUS_EXCEPTION:
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if (user_mode(regs)) {
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pr_debug("Instruction bus error exception in user mode\n");
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_exception(SIGBUS, regs, BUS_ADRERR, addr);
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return;
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}
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pr_warn("Instruction bus error exception in kernel mode.\n");
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die("bus exception", regs, SIGBUS);
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break;
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case MICROBLAZE_DBUS_EXCEPTION:
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if (user_mode(regs)) {
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pr_debug("Data bus error exception in user mode\n");
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_exception(SIGBUS, regs, BUS_ADRERR, addr);
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return;
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}
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pr_warn("Data bus error exception in kernel mode.\n");
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die("bus exception", regs, SIGBUS);
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break;
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case MICROBLAZE_DIV_ZERO_EXCEPTION:
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if (user_mode(regs)) {
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pr_debug("Divide by zero exception in user mode\n");
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_exception(SIGFPE, regs, FPE_INTDIV, addr);
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return;
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}
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pr_warn("Divide by zero exception in kernel mode.\n");
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die("Divide by zero exception", regs, SIGBUS);
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break;
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case MICROBLAZE_FPU_EXCEPTION:
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pr_debug("FPU exception\n");
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/* IEEE FP exception */
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/* I removed fsr variable and use code var for storing fsr */
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if (fsr & FSR_IO)
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fsr = FPE_FLTINV;
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else if (fsr & FSR_OF)
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fsr = FPE_FLTOVF;
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else if (fsr & FSR_UF)
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fsr = FPE_FLTUND;
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else if (fsr & FSR_DZ)
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fsr = FPE_FLTDIV;
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else if (fsr & FSR_DO)
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fsr = FPE_FLTRES;
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_exception(SIGFPE, regs, fsr, addr);
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break;
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case MICROBLAZE_PRIVILEGED_EXCEPTION:
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pr_debug("Privileged exception\n");
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_exception(SIGILL, regs, ILL_PRVOPC, addr);
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break;
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default:
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/* FIXME what to do in unexpected exception */
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pr_warn("Unexpected exception %02x PC=%08x in %s mode\n",
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type, (unsigned int) addr,
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kernel_mode(regs) ? "kernel" : "user");
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}
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return;
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}
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