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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 | #include <linux/bug.h> #include <linux/io.h> #include <linux/types.h> #include <linux/kdebug.h> #include <linux/signal.h> #include <linux/sched.h> #include <linux/uaccess.h> #include <linux/hardirq.h> #include <linux/kernel.h> #include <linux/kexec.h> #include <linux/module.h> #include <asm/unwinder.h> #include <asm/traps.h> static DEFINE_SPINLOCK(die_lock); void die(const char *str, struct pt_regs *regs, long err) { static int die_counter; oops_enter(); spin_lock_irq(&die_lock); console_verbose(); bust_spinlocks(1); printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter); print_modules(); show_regs(regs); printk("Process: %s (pid: %d, stack limit = %p)\n", current->comm, task_pid_nr(current), task_stack_page(current) + 1); if (!user_mode(regs) || in_interrupt()) dump_mem("Stack: ", regs->regs[15], THREAD_SIZE + (unsigned long)task_stack_page(current)); notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV); bust_spinlocks(0); add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); spin_unlock_irq(&die_lock); oops_exit(); if (kexec_should_crash(current)) crash_kexec(regs); if (in_interrupt()) panic("Fatal exception in interrupt"); if (panic_on_oops) panic("Fatal exception"); do_exit(SIGSEGV); } void die_if_kernel(const char *str, struct pt_regs *regs, long err) { if (!user_mode(regs)) die(str, regs, err); } /* * try and fix up kernelspace address errors * - userspace errors just cause EFAULT to be returned, resulting in SEGV * - kernel/userspace interfaces cause a jump to an appropriate handler * - other kernel errors are bad */ void die_if_no_fixup(const char *str, struct pt_regs *regs, long err) { if (!user_mode(regs)) { const struct exception_table_entry *fixup; fixup = search_exception_tables(regs->pc); if (fixup) { regs->pc = fixup->fixup; return; } die(str, regs, err); } } #ifdef CONFIG_GENERIC_BUG static void handle_BUG(struct pt_regs *regs) { const struct bug_entry *bug; unsigned long bugaddr = regs->pc; enum bug_trap_type tt; if (!is_valid_bugaddr(bugaddr)) goto invalid; bug = find_bug(bugaddr); /* Switch unwinders when unwind_stack() is called */ if (bug->flags & BUGFLAG_UNWINDER) unwinder_faulted = 1; tt = report_bug(bugaddr, regs); if (tt == BUG_TRAP_TYPE_WARN) { regs->pc += instruction_size(bugaddr); return; } invalid: die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff); } int is_valid_bugaddr(unsigned long addr) { insn_size_t opcode; if (addr < PAGE_OFFSET) return 0; if (probe_kernel_address((insn_size_t *)addr, opcode)) return 0; if (opcode == TRAPA_BUG_OPCODE) return 1; return 0; } #endif /* * Generic trap handler. */ BUILD_TRAP_HANDLER(debug) { TRAP_HANDLER_DECL; /* Rewind */ regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff, SIGTRAP) == NOTIFY_STOP) return; force_sig(SIGTRAP, current); } /* * Special handler for BUG() traps. */ BUILD_TRAP_HANDLER(bug) { TRAP_HANDLER_DECL; /* Rewind */ regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff, SIGTRAP) == NOTIFY_STOP) return; #ifdef CONFIG_GENERIC_BUG if (__kernel_text_address(instruction_pointer(regs))) { insn_size_t insn = *(insn_size_t *)instruction_pointer(regs); if (insn == TRAPA_BUG_OPCODE) handle_BUG(regs); return; } #endif force_sig(SIGTRAP, current); } BUILD_TRAP_HANDLER(nmi) { unsigned int cpu = smp_processor_id(); TRAP_HANDLER_DECL; nmi_enter(); nmi_count(cpu)++; switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) { case NOTIFY_OK: case NOTIFY_STOP: break; case NOTIFY_BAD: die("Fatal Non-Maskable Interrupt", regs, SIGINT); default: printk(KERN_ALERT "Got NMI, but nobody cared. Ignoring...\n"); break; } nmi_exit(); } |