Staging
v0.6.0
v0.6.0
https://github.com/torvalds/linux
Tip revision: 2734d6c1b1a089fb593ef6a23d4b70903526fe0c authored by Linus Torvalds on 18 July 2021, 21:13:49 UTC
Linux 5.14-rc2
Linux 5.14-rc2
Tip revision: 2734d6c
traps.c
/*
* Hardware exception handling
*
* Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
* Copyright (C) 2004 Microtronix Datacom Ltd.
* Copyright (C) 2001 Vic Phillips
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of this
* archive for more details.
*/
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/ptrace.h>
#include <asm/traps.h>
#include <asm/sections.h>
#include <linux/uaccess.h>
static DEFINE_SPINLOCK(die_lock);
static void _send_sig(int signo, int code, unsigned long addr)
{
force_sig_fault(signo, code, (void __user *) addr);
}
void die(const char *str, struct pt_regs *regs, long err)
{
console_verbose();
spin_lock_irq(&die_lock);
pr_warn("Oops: %s, sig: %ld\n", str, err);
show_regs(regs);
spin_unlock_irq(&die_lock);
/*
* do_exit() should take care of panic'ing from an interrupt
* context so we don't handle it here
*/
do_exit(err);
}
void _exception(int signo, struct pt_regs *regs, int code, unsigned long addr)
{
if (!user_mode(regs))
die("Exception in kernel mode", regs, signo);
_send_sig(signo, code, addr);
}
/*
* The show_stack() is external API which we do not use ourselves.
*/
int kstack_depth_to_print = 48;
void show_stack(struct task_struct *task, unsigned long *stack,
const char *loglvl)
{
unsigned long *endstack, addr;
int i;
if (!stack) {
if (task)
stack = (unsigned long *)task->thread.ksp;
else
stack = (unsigned long *)&stack;
}
addr = (unsigned long) stack;
endstack = (unsigned long *) PAGE_ALIGN(addr);
printk("%sStack from %08lx:", loglvl, (unsigned long)stack);
for (i = 0; i < kstack_depth_to_print; i++) {
if (stack + 1 > endstack)
break;
if (i % 8 == 0)
printk("%s\n ", loglvl);
printk("%s %08lx", loglvl, *stack++);
}
printk("%s\nCall Trace:", loglvl);
i = 0;
while (stack + 1 <= endstack) {
addr = *stack++;
/*
* If the address is either in the text segment of the
* kernel, or in the region which contains vmalloc'ed
* memory, it *may* be the address of a calling
* routine; if so, print it so that someone tracing
* down the cause of the crash will be able to figure
* out the call path that was taken.
*/
if (((addr >= (unsigned long) _stext) &&
(addr <= (unsigned long) _etext))) {
if (i % 4 == 0)
pr_emerg("\n ");
printk("%s [<%08lx>]", loglvl, addr);
i++;
}
}
printk("%s\n", loglvl);
}
void __init trap_init(void)
{
/* Nothing to do here */
}
/* Breakpoint handler */
asmlinkage void breakpoint_c(struct pt_regs *fp)
{
/*
* The breakpoint entry code has moved the PC on by 4 bytes, so we must
* move it back. This could be done on the host but we do it here
* because monitor.S of JTAG gdbserver does it too.
*/
fp->ea -= 4;
_exception(SIGTRAP, fp, TRAP_BRKPT, fp->ea);
}
#ifndef CONFIG_NIOS2_ALIGNMENT_TRAP
/* Alignment exception handler */
asmlinkage void handle_unaligned_c(struct pt_regs *fp, int cause)
{
unsigned long addr = RDCTL(CTL_BADADDR);
cause >>= 2;
fp->ea -= 4;
if (fixup_exception(fp))
return;
if (!user_mode(fp)) {
pr_alert("Unaligned access from kernel mode, this might be a hardware\n");
pr_alert("problem, dump registers and restart the instruction\n");
pr_alert(" BADADDR 0x%08lx\n", addr);
pr_alert(" cause %d\n", cause);
pr_alert(" op-code 0x%08lx\n", *(unsigned long *)(fp->ea));
show_regs(fp);
return;
}
_exception(SIGBUS, fp, BUS_ADRALN, addr);
}
#endif /* CONFIG_NIOS2_ALIGNMENT_TRAP */
/* Illegal instruction handler */
asmlinkage void handle_illegal_c(struct pt_regs *fp)
{
fp->ea -= 4;
_exception(SIGILL, fp, ILL_ILLOPC, fp->ea);
}
/* Supervisor instruction handler */
asmlinkage void handle_supervisor_instr(struct pt_regs *fp)
{
fp->ea -= 4;
_exception(SIGILL, fp, ILL_PRVOPC, fp->ea);
}
/* Division error handler */
asmlinkage void handle_diverror_c(struct pt_regs *fp)
{
fp->ea -= 4;
_exception(SIGFPE, fp, FPE_INTDIV, fp->ea);
}
/* Unhandled exception handler */
asmlinkage void unhandled_exception(struct pt_regs *regs, int cause)
{
unsigned long addr = RDCTL(CTL_BADADDR);
cause /= 4;
pr_emerg("Unhandled exception #%d in %s mode (badaddr=0x%08lx)\n",
cause, user_mode(regs) ? "user" : "kernel", addr);
regs->ea -= 4;
show_regs(regs);
pr_emerg("opcode: 0x%08lx\n", *(unsigned long *)(regs->ea));
}
asmlinkage void handle_trap_1_c(struct pt_regs *fp)
{
_send_sig(SIGUSR1, 0, fp->ea);
}
asmlinkage void handle_trap_2_c(struct pt_regs *fp)
{
_send_sig(SIGUSR2, 0, fp->ea);
}
asmlinkage void handle_trap_3_c(struct pt_regs *fp)
{
_send_sig(SIGILL, ILL_ILLTRP, fp->ea);
}