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