236 lines
6.1 KiB
C
236 lines
6.1 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-only
|
||
|
|
/*
|
||
|
|
* Copyright (C) 2012 Regents of the University of California
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/cpu.h>
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/init.h>
|
||
|
|
#include <linux/sched.h>
|
||
|
|
#include <linux/sched/debug.h>
|
||
|
|
#include <linux/sched/signal.h>
|
||
|
|
#include <linux/signal.h>
|
||
|
|
#include <linux/kdebug.h>
|
||
|
|
#include <linux/uaccess.h>
|
||
|
|
#include <linux/kprobes.h>
|
||
|
|
#include <linux/mm.h>
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/irq.h>
|
||
|
|
|
||
|
|
#include <asm/asm-prototypes.h>
|
||
|
|
#include <asm/bug.h>
|
||
|
|
#include <asm/processor.h>
|
||
|
|
#include <asm/ptrace.h>
|
||
|
|
#include <asm/csr.h>
|
||
|
|
|
||
|
|
int show_unhandled_signals = 1;
|
||
|
|
|
||
|
|
static DEFINE_SPINLOCK(die_lock);
|
||
|
|
|
||
|
|
void die(struct pt_regs *regs, const char *str)
|
||
|
|
{
|
||
|
|
static int die_counter;
|
||
|
|
int ret;
|
||
|
|
|
||
|
|
oops_enter();
|
||
|
|
|
||
|
|
spin_lock_irq(&die_lock);
|
||
|
|
console_verbose();
|
||
|
|
bust_spinlocks(1);
|
||
|
|
|
||
|
|
pr_emerg("%s [#%d]\n", str, ++die_counter);
|
||
|
|
print_modules();
|
||
|
|
show_regs(regs);
|
||
|
|
|
||
|
|
ret = notify_die(DIE_OOPS, str, regs, 0, regs->cause, SIGSEGV);
|
||
|
|
|
||
|
|
bust_spinlocks(0);
|
||
|
|
add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
|
||
|
|
spin_unlock_irq(&die_lock);
|
||
|
|
oops_exit();
|
||
|
|
|
||
|
|
if (in_interrupt())
|
||
|
|
panic("Fatal exception in interrupt");
|
||
|
|
if (panic_on_oops)
|
||
|
|
panic("Fatal exception");
|
||
|
|
if (ret != NOTIFY_STOP)
|
||
|
|
make_task_dead(SIGSEGV);
|
||
|
|
}
|
||
|
|
|
||
|
|
void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr)
|
||
|
|
{
|
||
|
|
struct task_struct *tsk = current;
|
||
|
|
|
||
|
|
if (show_unhandled_signals && unhandled_signal(tsk, signo)
|
||
|
|
&& printk_ratelimit()) {
|
||
|
|
pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT,
|
||
|
|
tsk->comm, task_pid_nr(tsk), signo, code, addr);
|
||
|
|
print_vma_addr(KERN_CONT " in ", instruction_pointer(regs));
|
||
|
|
pr_cont("\n");
|
||
|
|
__show_regs(regs);
|
||
|
|
}
|
||
|
|
|
||
|
|
force_sig_fault(signo, code, (void __user *)addr);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void do_trap_error(struct pt_regs *regs, int signo, int code,
|
||
|
|
unsigned long addr, const char *str)
|
||
|
|
{
|
||
|
|
current->thread.bad_cause = regs->cause;
|
||
|
|
|
||
|
|
if (user_mode(regs)) {
|
||
|
|
do_trap(regs, signo, code, addr);
|
||
|
|
} else {
|
||
|
|
if (!fixup_exception(regs))
|
||
|
|
die(regs, str);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
#if defined (CONFIG_XIP_KERNEL) && defined (CONFIG_RISCV_ERRATA_ALTERNATIVE)
|
||
|
|
#define __trap_section __section(".xip.traps")
|
||
|
|
#else
|
||
|
|
#define __trap_section
|
||
|
|
#endif
|
||
|
|
#define DO_ERROR_INFO(name, signo, code, str) \
|
||
|
|
asmlinkage __visible __trap_section void name(struct pt_regs *regs) \
|
||
|
|
{ \
|
||
|
|
do_trap_error(regs, signo, code, regs->epc, "Oops - " str); \
|
||
|
|
}
|
||
|
|
|
||
|
|
DO_ERROR_INFO(do_trap_unknown,
|
||
|
|
SIGILL, ILL_ILLTRP, "unknown exception");
|
||
|
|
DO_ERROR_INFO(do_trap_insn_misaligned,
|
||
|
|
SIGBUS, BUS_ADRALN, "instruction address misaligned");
|
||
|
|
DO_ERROR_INFO(do_trap_insn_fault,
|
||
|
|
SIGSEGV, SEGV_ACCERR, "instruction access fault");
|
||
|
|
DO_ERROR_INFO(do_trap_insn_illegal,
|
||
|
|
SIGILL, ILL_ILLOPC, "illegal instruction");
|
||
|
|
DO_ERROR_INFO(do_trap_load_fault,
|
||
|
|
SIGSEGV, SEGV_ACCERR, "load access fault");
|
||
|
|
#ifndef CONFIG_RISCV_M_MODE
|
||
|
|
DO_ERROR_INFO(do_trap_load_misaligned,
|
||
|
|
SIGBUS, BUS_ADRALN, "Oops - load address misaligned");
|
||
|
|
DO_ERROR_INFO(do_trap_store_misaligned,
|
||
|
|
SIGBUS, BUS_ADRALN, "Oops - store (or AMO) address misaligned");
|
||
|
|
#else
|
||
|
|
int handle_misaligned_load(struct pt_regs *regs);
|
||
|
|
int handle_misaligned_store(struct pt_regs *regs);
|
||
|
|
|
||
|
|
asmlinkage void __trap_section do_trap_load_misaligned(struct pt_regs *regs)
|
||
|
|
{
|
||
|
|
if (!handle_misaligned_load(regs))
|
||
|
|
return;
|
||
|
|
do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
|
||
|
|
"Oops - load address misaligned");
|
||
|
|
}
|
||
|
|
|
||
|
|
asmlinkage void __trap_section do_trap_store_misaligned(struct pt_regs *regs)
|
||
|
|
{
|
||
|
|
if (!handle_misaligned_store(regs))
|
||
|
|
return;
|
||
|
|
do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
|
||
|
|
"Oops - store (or AMO) address misaligned");
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
DO_ERROR_INFO(do_trap_store_fault,
|
||
|
|
SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault");
|
||
|
|
DO_ERROR_INFO(do_trap_ecall_u,
|
||
|
|
SIGILL, ILL_ILLTRP, "environment call from U-mode");
|
||
|
|
DO_ERROR_INFO(do_trap_ecall_s,
|
||
|
|
SIGILL, ILL_ILLTRP, "environment call from S-mode");
|
||
|
|
DO_ERROR_INFO(do_trap_ecall_m,
|
||
|
|
SIGILL, ILL_ILLTRP, "environment call from M-mode");
|
||
|
|
|
||
|
|
static inline unsigned long get_break_insn_length(unsigned long pc)
|
||
|
|
{
|
||
|
|
bug_insn_t insn;
|
||
|
|
|
||
|
|
if (get_kernel_nofault(insn, (bug_insn_t *)pc))
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
return GET_INSN_LENGTH(insn);
|
||
|
|
}
|
||
|
|
|
||
|
|
asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs)
|
||
|
|
{
|
||
|
|
#ifdef CONFIG_KPROBES
|
||
|
|
if (kprobe_single_step_handler(regs))
|
||
|
|
return;
|
||
|
|
|
||
|
|
if (kprobe_breakpoint_handler(regs))
|
||
|
|
return;
|
||
|
|
#endif
|
||
|
|
#ifdef CONFIG_UPROBES
|
||
|
|
if (uprobe_single_step_handler(regs))
|
||
|
|
return;
|
||
|
|
|
||
|
|
if (uprobe_breakpoint_handler(regs))
|
||
|
|
return;
|
||
|
|
#endif
|
||
|
|
current->thread.bad_cause = regs->cause;
|
||
|
|
|
||
|
|
if (user_mode(regs))
|
||
|
|
force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->epc);
|
||
|
|
#ifdef CONFIG_KGDB
|
||
|
|
else if (notify_die(DIE_TRAP, "EBREAK", regs, 0, regs->cause, SIGTRAP)
|
||
|
|
== NOTIFY_STOP)
|
||
|
|
return;
|
||
|
|
#endif
|
||
|
|
else if (report_bug(regs->epc, regs) == BUG_TRAP_TYPE_WARN)
|
||
|
|
regs->epc += get_break_insn_length(regs->epc);
|
||
|
|
else
|
||
|
|
die(regs, "Kernel BUG");
|
||
|
|
}
|
||
|
|
NOKPROBE_SYMBOL(do_trap_break);
|
||
|
|
|
||
|
|
#ifdef CONFIG_GENERIC_BUG
|
||
|
|
int is_valid_bugaddr(unsigned long pc)
|
||
|
|
{
|
||
|
|
bug_insn_t insn;
|
||
|
|
|
||
|
|
if (pc < VMALLOC_START)
|
||
|
|
return 0;
|
||
|
|
if (get_kernel_nofault(insn, (bug_insn_t *)pc))
|
||
|
|
return 0;
|
||
|
|
if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32)
|
||
|
|
return (insn == __BUG_INSN_32);
|
||
|
|
else
|
||
|
|
return ((insn & __COMPRESSED_INSN_MASK) == __BUG_INSN_16);
|
||
|
|
}
|
||
|
|
#endif /* CONFIG_GENERIC_BUG */
|
||
|
|
|
||
|
|
#ifdef CONFIG_VMAP_STACK
|
||
|
|
static DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)],
|
||
|
|
overflow_stack)__aligned(16);
|
||
|
|
/*
|
||
|
|
* shadow stack, handled_ kernel_ stack_ overflow(in kernel/entry.S) is used
|
||
|
|
* to get per-cpu overflow stack(get_overflow_stack).
|
||
|
|
*/
|
||
|
|
long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE/sizeof(long)];
|
||
|
|
asmlinkage unsigned long get_overflow_stack(void)
|
||
|
|
{
|
||
|
|
return (unsigned long)this_cpu_ptr(overflow_stack) +
|
||
|
|
OVERFLOW_STACK_SIZE;
|
||
|
|
}
|
||
|
|
|
||
|
|
asmlinkage void handle_bad_stack(struct pt_regs *regs)
|
||
|
|
{
|
||
|
|
unsigned long tsk_stk = (unsigned long)current->stack;
|
||
|
|
unsigned long ovf_stk = (unsigned long)this_cpu_ptr(overflow_stack);
|
||
|
|
|
||
|
|
console_verbose();
|
||
|
|
|
||
|
|
pr_emerg("Insufficient stack space to handle exception!\n");
|
||
|
|
pr_emerg("Task stack: [0x%016lx..0x%016lx]\n",
|
||
|
|
tsk_stk, tsk_stk + THREAD_SIZE);
|
||
|
|
pr_emerg("Overflow stack: [0x%016lx..0x%016lx]\n",
|
||
|
|
ovf_stk, ovf_stk + OVERFLOW_STACK_SIZE);
|
||
|
|
|
||
|
|
__show_regs(regs);
|
||
|
|
panic("Kernel stack overflow");
|
||
|
|
|
||
|
|
for (;;)
|
||
|
|
wait_for_interrupt();
|
||
|
|
}
|
||
|
|
#endif
|