/* * Copyright (C) 1991, 1992 Linus Torvalds * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs */ #include <linux/kallsyms.h> #include <linux/kprobes.h> #include <linux/uaccess.h> #include <linux/utsname.h> #include <linux/hardirq.h> #include <linux/kdebug.h> #include <linux/module.h> #include <linux/ptrace.h> #include <linux/ftrace.h> #include <linux/kexec.h> #include <linux/bug.h> #include <linux/nmi.h> #include <linux/sysfs.h> #include <asm/stacktrace.h> int panic_on_unrecovered_nmi; int panic_on_io_nmi; unsigned int code_bytes = 64; int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE; static int die_counter; void printk_address(unsigned long address, int reliable) { pr_cont(" [<%p>] %s%pB\n", (void *)address, reliable ? "" : "? ", (void *)address); } #ifdef CONFIG_FUNCTION_GRAPH_TRACER static void print_ftrace_graph_addr(unsigned long addr, void *data, const struct stacktrace_ops *ops, struct thread_info *tinfo, int *graph) { struct task_struct *task; unsigned long ret_addr; int index; if (addr != (unsigned long)return_to_handler) return; task = tinfo->task; index = task->curr_ret_stack; if (!task->ret_stack || index < *graph) return; index -= *graph; ret_addr = task->ret_stack[index].ret; ops->address(data, ret_addr, 1); (*graph)++; } #else static inline void print_ftrace_graph_addr(unsigned long addr, void *data, const struct stacktrace_ops *ops, struct thread_info *tinfo, int *graph) { } #endif /* * x86-64 can have up to three kernel stacks: * process stack * interrupt stack * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack */ static inline int valid_stack_ptr(struct thread_info *tinfo, void *p, unsigned int size, void *end) { void *t = tinfo; if (end) { if (p < end && p >= (end-THREAD_SIZE)) return 1; else return 0; } return p > t && p < t + THREAD_SIZE - size; } unsigned long print_context_stack(struct thread_info *tinfo, unsigned long *stack, unsigned long bp, const struct stacktrace_ops *ops, void *data, unsigned long *end, int *graph) { struct stack_frame *frame = (struct stack_frame *)bp; while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) { unsigned long addr; addr = *stack; if (__kernel_text_address(addr)) { if ((unsigned long) stack == bp + sizeof(long)) { ops->address(data, addr, 1); frame = frame->next_frame; bp = (unsigned long) frame; } else { ops->address(data, addr, 0); } print_ftrace_graph_addr(addr, data, ops, tinfo, graph); } stack++; } return bp; } EXPORT_SYMBOL_GPL(print_context_stack); unsigned long print_context_stack_bp(struct thread_info *tinfo, unsigned long *stack, unsigned long bp, const struct stacktrace_ops *ops, void *data, unsigned long *end, int *graph) { struct stack_frame *frame = (struct stack_frame *)bp; unsigned long *ret_addr = &frame->return_address; while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) { unsigned long addr = *ret_addr; if (!__kernel_text_address(addr)) break; ops->address(data, addr, 1); frame = frame->next_frame; ret_addr = &frame->return_address; print_ftrace_graph_addr(addr, data, ops, tinfo, graph); } return (unsigned long)frame; } EXPORT_SYMBOL_GPL(print_context_stack_bp); static int print_trace_stack(void *data, char *name) { printk("%s <%s> ", (char *)data, name); return 0; } /* * Print one address/symbol entries per line. */ static void print_trace_address(void *data, unsigned long addr, int reliable) { touch_nmi_watchdog(); printk(data); printk_address(addr, reliable); } static const struct stacktrace_ops print_trace_ops = { .stack = print_trace_stack, .address = print_trace_address, .walk_stack = print_context_stack, }; void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, unsigned long *stack, unsigned long bp, char *log_lvl) { printk("%sCall Trace:\n", log_lvl); dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl); } void show_trace(struct task_struct *task, struct pt_regs *regs, unsigned long *stack, unsigned long bp) { show_trace_log_lvl(task, regs, stack, bp, ""); } void show_stack(struct task_struct *task, unsigned long *sp) { show_stack_log_lvl(task, NULL, sp, 0, ""); } /* * The architecture-independent dump_stack generator */ void dump_stack(void) { unsigned long bp; unsigned long stack; bp = stack_frame(current, NULL); printk("Pid: %d, comm: %.20s %s %s %.*s\n", current->pid, current->comm, print_tainted(), init_utsname()->release, (int)strcspn(init_utsname()->version, " "), init_utsname()->version); show_trace(NULL, NULL, &stack, bp); } EXPORT_SYMBOL(dump_stack); static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED; static int die_owner = -1; static unsigned int die_nest_count; unsigned __kprobes long oops_begin(void) { int cpu; unsigned long flags; oops_enter(); /* racy, but better than risking deadlock. */ raw_local_irq_save(flags); cpu = smp_processor_id(); if (!arch_spin_trylock(&die_lock)) { if (cpu == die_owner) /* nested oops. should stop eventually */; else arch_spin_lock(&die_lock); } die_nest_count++; die_owner = cpu; console_verbose(); bust_spinlocks(1); return flags; } EXPORT_SYMBOL_GPL(oops_begin); void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr) { if (regs && kexec_should_crash(current)) crash_kexec(regs); bust_spinlocks(0); die_owner = -1; add_taint(TAINT_DIE); die_nest_count--; if (!die_nest_count) /* Nest count reaches zero, release the lock. */ arch_spin_unlock(&die_lock); raw_local_irq_restore(flags); oops_exit(); if (!signr) return; if (in_interrupt()) panic("Fatal exception in interrupt"); if (panic_on_oops) panic("Fatal exception"); do_exit(signr); } int __kprobes __die(const char *str, struct pt_regs *regs, long err) { #ifdef CONFIG_X86_32 unsigned short ss; unsigned long sp; #endif printk(KERN_DEFAULT "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter); #ifdef CONFIG_PREEMPT printk("PREEMPT "); #endif #ifdef CONFIG_SMP printk("SMP "); #endif #ifdef CONFIG_DEBUG_PAGEALLOC printk("DEBUG_PAGEALLOC"); #endif printk("\n"); if (notify_die(DIE_OOPS, str, regs, err, current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP) return 1; print_modules(); show_regs(regs); #ifdef CONFIG_X86_32 if (user_mode_vm(regs)) { sp = regs->sp; ss = regs->ss & 0xffff; } else { sp = kernel_stack_pointer(regs); savesegment(ss, ss); } printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip); print_symbol("%s", regs->ip); printk(" SS:ESP %04x:%08lx\n", ss, sp); #else /* Executive summary in case the oops scrolled away */ printk(KERN_ALERT "RIP "); printk_address(regs->ip, 1); printk(" RSP <%016lx>\n", regs->sp); #endif return 0; } /* * This is gone through when something in the kernel has done something bad * and is about to be terminated: */ void die(const char *str, struct pt_regs *regs, long err) { unsigned long flags = oops_begin(); int sig = SIGSEGV; if (!user_mode_vm(regs)) report_bug(regs->ip, regs); if (__die(str, regs, err)) sig = 0; oops_end(flags, regs, sig); } static int __init kstack_setup(char *s) { ssize_t ret; unsigned long val; if (!s) return -EINVAL; ret = kstrtoul(s, 0, &val); if (ret) return ret; kstack_depth_to_print = val; return 0; } early_param("kstack", kstack_setup); static int __init code_bytes_setup(char *s) { ssize_t ret; unsigned long val; if (!s) return -EINVAL; ret = kstrtoul(s, 0, &val); if (ret) return ret; code_bytes = val; if (code_bytes > 8192) code_bytes = 8192; return 1; } __setup("code_bytes=", code_bytes_setup);