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    Subject[PATCH 2/2] x86_64: split out dumpstack code from traps_64.c
    Date
    The dumpstack code is logically quite independent from the
    hardware traps. Split it out into its own file.

    Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
    ---
    arch/x86/kernel/Makefile | 4 +-
    arch/x86/kernel/dumpstack_64.c | 567 ++++++++++++++++++++++++++++++++++++++++
    arch/x86/kernel/traps_64.c | 549 --------------------------------------
    3 files changed, 569 insertions(+), 551 deletions(-)
    create mode 100644 arch/x86/kernel/dumpstack_64.c

    diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
    index ed1af8a..6ccada6 100644
    --- a/arch/x86/kernel/Makefile
    +++ b/arch/x86/kernel/Makefile
    @@ -24,12 +24,12 @@ CFLAGS_tsc.o := $(nostackp)
    CFLAGS_paravirt.o := $(nostackp)

    obj-y := process_$(BITS).o signal_$(BITS).o entry_$(BITS).o
    -obj-y += traps_$(BITS).o irq_$(BITS).o
    +obj-y += traps_$(BITS).o irq_$(BITS).o dumpstack_$(BITS).o
    obj-y += time_$(BITS).o ioport.o ldt.o
    obj-y += setup.o i8259.o irqinit_$(BITS).o setup_percpu.o
    obj-$(CONFIG_X86_VISWS) += visws_quirks.o
    obj-$(CONFIG_X86_32) += probe_roms_32.o
    -obj-$(CONFIG_X86_32) += sys_i386_32.o i386_ksyms_32.o dumpstack_32.o
    +obj-$(CONFIG_X86_32) += sys_i386_32.o i386_ksyms_32.o
    obj-$(CONFIG_X86_64) += sys_x86_64.o x8664_ksyms_64.o
    obj-$(CONFIG_X86_64) += syscall_64.o vsyscall_64.o
    obj-y += bootflag.o e820.o
    diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
    new file mode 100644
    index 0000000..11f22d2
    --- /dev/null
    +++ b/arch/x86/kernel/dumpstack_64.c
    @@ -0,0 +1,567 @@
    +/*
    + * 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/kexec.h>
    +#include <linux/bug.h>
    +#include <linux/nmi.h>
    +
    +#include <asm/stacktrace.h>
    +
    +int panic_on_unrecovered_nmi;
    +int kstack_depth_to_print = 12;
    +static unsigned int code_bytes = 64;
    +static int die_counter;
    +
    +void printk_address(unsigned long address, int reliable)
    +{
    + printk(" [<%016lx>] %s%pS\n",
    + address, reliable ? "" : "? ", (void *) address);
    +}
    +
    +static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
    + unsigned *usedp, char **idp)
    +{
    + static char ids[][8] = {
    + [DEBUG_STACK - 1] = "#DB",
    + [NMI_STACK - 1] = "NMI",
    + [DOUBLEFAULT_STACK - 1] = "#DF",
    + [STACKFAULT_STACK - 1] = "#SS",
    + [MCE_STACK - 1] = "#MC",
    +#if DEBUG_STKSZ > EXCEPTION_STKSZ
    + [N_EXCEPTION_STACKS ...
    + N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
    +#endif
    + };
    + unsigned k;
    +
    + /*
    + * Iterate over all exception stacks, and figure out whether
    + * 'stack' is in one of them:
    + */
    + for (k = 0; k < N_EXCEPTION_STACKS; k++) {
    + unsigned long end = per_cpu(orig_ist, cpu).ist[k];
    + /*
    + * Is 'stack' above this exception frame's end?
    + * If yes then skip to the next frame.
    + */
    + if (stack >= end)
    + continue;
    + /*
    + * Is 'stack' above this exception frame's start address?
    + * If yes then we found the right frame.
    + */
    + if (stack >= end - EXCEPTION_STKSZ) {
    + /*
    + * Make sure we only iterate through an exception
    + * stack once. If it comes up for the second time
    + * then there's something wrong going on - just
    + * break out and return NULL:
    + */
    + if (*usedp & (1U << k))
    + break;
    + *usedp |= 1U << k;
    + *idp = ids[k];
    + return (unsigned long *)end;
    + }
    + /*
    + * If this is a debug stack, and if it has a larger size than
    + * the usual exception stacks, then 'stack' might still
    + * be within the lower portion of the debug stack:
    + */
    +#if DEBUG_STKSZ > EXCEPTION_STKSZ
    + if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
    + unsigned j = N_EXCEPTION_STACKS - 1;
    +
    + /*
    + * Black magic. A large debug stack is composed of
    + * multiple exception stack entries, which we
    + * iterate through now. Dont look:
    + */
    + do {
    + ++j;
    + end -= EXCEPTION_STKSZ;
    + ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
    + } while (stack < end - EXCEPTION_STKSZ);
    + if (*usedp & (1U << j))
    + break;
    + *usedp |= 1U << j;
    + *idp = ids[j];
    + return (unsigned long *)end;
    + }
    +#endif
    + }
    + return NULL;
    +}
    +
    +/*
    + * 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;
    +}
    +
    +/* The form of the top of the frame on the stack */
    +struct stack_frame {
    + struct stack_frame *next_frame;
    + unsigned long return_address;
    +};
    +
    +static inline 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)
    +{
    + 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 + 8) {
    + ops->address(data, addr, 1);
    + frame = frame->next_frame;
    + bp = (unsigned long) frame;
    + } else {
    + ops->address(data, addr, bp == 0);
    + }
    + }
    + stack++;
    + }
    + return bp;
    +}
    +
    +void dump_trace(struct task_struct *task, struct pt_regs *regs,
    + unsigned long *stack, unsigned long bp,
    + const struct stacktrace_ops *ops, void *data)
    +{
    + const unsigned cpu = get_cpu();
    + unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
    + unsigned used = 0;
    + struct thread_info *tinfo;
    +
    + if (!task)
    + task = current;
    +
    + if (!stack) {
    + unsigned long dummy;
    + stack = &dummy;
    + if (task && task != current)
    + stack = (unsigned long *)task->thread.sp;
    + }
    +
    +#ifdef CONFIG_FRAME_POINTER
    + if (!bp) {
    + if (task == current) {
    + /* Grab bp right from our regs */
    + asm("movq %%rbp, %0" : "=r" (bp) : );
    + } else {
    + /* bp is the last reg pushed by switch_to */
    + bp = *(unsigned long *) task->thread.sp;
    + }
    + }
    +#endif
    +
    + /*
    + * Print function call entries in all stacks, starting at the
    + * current stack address. If the stacks consist of nested
    + * exceptions
    + */
    + tinfo = task_thread_info(task);
    + for (;;) {
    + char *id;
    + unsigned long *estack_end;
    + estack_end = in_exception_stack(cpu, (unsigned long)stack,
    + &used, &id);
    +
    + if (estack_end) {
    + if (ops->stack(data, id) < 0)
    + break;
    +
    + bp = print_context_stack(tinfo, stack, bp, ops,
    + data, estack_end);
    + ops->stack(data, "<EOE>");
    + /*
    + * We link to the next stack via the
    + * second-to-last pointer (index -2 to end) in the
    + * exception stack:
    + */
    + stack = (unsigned long *) estack_end[-2];
    + continue;
    + }
    + if (irqstack_end) {
    + unsigned long *irqstack;
    + irqstack = irqstack_end -
    + (IRQSTACKSIZE - 64) / sizeof(*irqstack);
    +
    + if (stack >= irqstack && stack < irqstack_end) {
    + if (ops->stack(data, "IRQ") < 0)
    + break;
    + bp = print_context_stack(tinfo, stack, bp,
    + ops, data, irqstack_end);
    + /*
    + * We link to the next stack (which would be
    + * the process stack normally) the last
    + * pointer (index -1 to end) in the IRQ stack:
    + */
    + stack = (unsigned long *) (irqstack_end[-1]);
    + irqstack_end = NULL;
    + ops->stack(data, "EOI");
    + continue;
    + }
    + }
    + break;
    + }
    +
    + /*
    + * This handles the process stack:
    + */
    + bp = print_context_stack(tinfo, stack, bp, ops, data, NULL);
    + put_cpu();
    +}
    +EXPORT_SYMBOL(dump_trace);
    +
    +static void
    +print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
    +{
    + print_symbol(msg, symbol);
    + printk("\n");
    +}
    +
    +static void print_trace_warning(void *data, char *msg)
    +{
    + printk("%s\n", msg);
    +}
    +
    +static int print_trace_stack(void *data, char *name)
    +{
    + printk(" <%s> ", name);
    + return 0;
    +}
    +
    +static void print_trace_address(void *data, unsigned long addr, int reliable)
    +{
    + touch_nmi_watchdog();
    + printk_address(addr, reliable);
    +}
    +
    +static const struct stacktrace_ops print_trace_ops = {
    + .warning = print_trace_warning,
    + .warning_symbol = print_trace_warning_symbol,
    + .stack = print_trace_stack,
    + .address = print_trace_address,
    +};
    +
    +static void
    +show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
    + unsigned long *stack, unsigned long bp, char *log_lvl)
    +{
    + printk("Call Trace:\n");
    + 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, "");
    +}
    +
    +static void
    +show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
    + unsigned long *sp, unsigned long bp, char *log_lvl)
    +{
    + unsigned long *stack;
    + int i;
    + const int cpu = smp_processor_id();
    + unsigned long *irqstack_end =
    + (unsigned long *) (cpu_pda(cpu)->irqstackptr);
    + unsigned long *irqstack =
    + (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
    +
    + /*
    + * debugging aid: "show_stack(NULL, NULL);" prints the
    + * back trace for this cpu.
    + */
    +
    + if (sp == NULL) {
    + if (task)
    + sp = (unsigned long *)task->thread.sp;
    + else
    + sp = (unsigned long *)&sp;
    + }
    +
    + stack = sp;
    + for (i = 0; i < kstack_depth_to_print; i++) {
    + if (stack >= irqstack && stack <= irqstack_end) {
    + if (stack == irqstack_end) {
    + stack = (unsigned long *) (irqstack_end[-1]);
    + printk(" <EOI> ");
    + }
    + } else {
    + if (((long) stack & (THREAD_SIZE-1)) == 0)
    + break;
    + }
    + if (i && ((i % 4) == 0))
    + printk("\n");
    + printk(" %016lx", *stack++);
    + touch_nmi_watchdog();
    + }
    + printk("\n");
    + show_trace_log_lvl(task, regs, sp, bp, log_lvl);
    +}
    +
    +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 = 0;
    + unsigned long stack;
    +
    +#ifdef CONFIG_FRAME_POINTER
    + if (!bp)
    + asm("movq %%rbp, %0" : "=r" (bp) : );
    +#endif
    +
    + 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);
    +
    +void show_registers(struct pt_regs *regs)
    +{
    + int i;
    + unsigned long sp;
    + const int cpu = smp_processor_id();
    + struct task_struct *cur = cpu_pda(cpu)->pcurrent;
    +
    + sp = regs->sp;
    + printk("CPU %d ", cpu);
    + __show_regs(regs, 1);
    + printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
    + cur->comm, cur->pid, task_thread_info(cur), cur);
    +
    + /*
    + * When in-kernel, we also print out the stack and code at the
    + * time of the fault..
    + */
    + if (!user_mode(regs)) {
    + unsigned int code_prologue = code_bytes * 43 / 64;
    + unsigned int code_len = code_bytes;
    + unsigned char c;
    + u8 *ip;
    +
    + printk("Stack: ");
    + show_stack_log_lvl(NULL, regs, (unsigned long *)sp,
    + regs->bp, "");
    +
    + printk(KERN_EMERG "Code: ");
    +
    + ip = (u8 *)regs->ip - code_prologue;
    + if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
    + /* try starting at RIP */
    + ip = (u8 *)regs->ip;
    + code_len = code_len - code_prologue + 1;
    + }
    + for (i = 0; i < code_len; i++, ip++) {
    + if (ip < (u8 *)PAGE_OFFSET ||
    + probe_kernel_address(ip, c)) {
    + printk(" Bad RIP value.");
    + break;
    + }
    + if (ip == (u8 *)regs->ip)
    + printk("<%02x> ", c);
    + else
    + printk("%02x ", c);
    + }
    + }
    + printk("\n");
    +}
    +
    +int is_valid_bugaddr(unsigned long ip)
    +{
    + unsigned short ud2;
    +
    + if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2)))
    + return 0;
    +
    + return ud2 == 0x0b0f;
    +}
    +
    +static raw_spinlock_t die_lock = __RAW_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 (!__raw_spin_trylock(&die_lock)) {
    + if (cpu == die_owner)
    + /* nested oops. should stop eventually */;
    + else
    + __raw_spin_lock(&die_lock);
    + }
    + die_nest_count++;
    + die_owner = cpu;
    + console_verbose();
    + bust_spinlocks(1);
    + return flags;
    +}
    +
    +void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
    +{
    + die_owner = -1;
    + bust_spinlocks(0);
    + die_nest_count--;
    + if (!die_nest_count)
    + /* Nest count reaches zero, release the lock. */
    + __raw_spin_unlock(&die_lock);
    + raw_local_irq_restore(flags);
    + if (!regs) {
    + oops_exit();
    + return;
    + }
    + if (in_nmi())
    + panic("Fatal exception in non-maskable interrupt");
    + if (in_interrupt())
    + panic("Fatal exception in interrupt");
    + if (panic_on_oops)
    + panic("Fatal exception");
    + oops_exit();
    + do_exit(signr);
    +}
    +
    +int __kprobes __die(const char *str, struct pt_regs *regs, long err)
    +{
    + printk(KERN_EMERG "%s: %04lx [%u] ", 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_no, SIGSEGV) == NOTIFY_STOP)
    + return 1;
    +
    + show_registers(regs);
    + add_taint(TAINT_DIE);
    + /* Executive summary in case the oops scrolled away */
    + printk(KERN_ALERT "RIP ");
    + printk_address(regs->ip, 1);
    + printk(" RSP <%016lx>\n", regs->sp);
    + if (kexec_should_crash(current))
    + crash_kexec(regs);
    + return 0;
    +}
    +
    +void die(const char *str, struct pt_regs *regs, long err)
    +{
    + unsigned long flags = oops_begin();
    +
    + if (!user_mode(regs))
    + report_bug(regs->ip, regs);
    +
    + if (__die(str, regs, err))
    + regs = NULL;
    + oops_end(flags, regs, SIGSEGV);
    +}
    +
    +notrace __kprobes void
    +die_nmi(char *str, struct pt_regs *regs, int do_panic)
    +{
    + unsigned long flags;
    +
    + if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
    + return;
    +
    + flags = oops_begin();
    + /*
    + * We are in trouble anyway, lets at least try
    + * to get a message out.
    + */
    + printk(KERN_EMERG "%s", str);
    + printk(" on CPU%d, ip %08lx, registers:\n",
    + smp_processor_id(), regs->ip);
    + show_registers(regs);
    + if (kexec_should_crash(current))
    + crash_kexec(regs);
    + if (do_panic || panic_on_oops)
    + panic("Non maskable interrupt");
    + oops_end(flags, NULL, SIGBUS);
    + nmi_exit();
    + local_irq_enable();
    + do_exit(SIGBUS);
    +}
    +
    +static int __init oops_setup(char *s)
    +{
    + if (!s)
    + return -EINVAL;
    + if (!strcmp(s, "panic"))
    + panic_on_oops = 1;
    + return 0;
    +}
    +early_param("oops", oops_setup);
    +
    +static int __init kstack_setup(char *s)
    +{
    + if (!s)
    + return -EINVAL;
    + kstack_depth_to_print = simple_strtoul(s, NULL, 0);
    + return 0;
    +}
    +early_param("kstack", kstack_setup);
    +
    +static int __init code_bytes_setup(char *s)
    +{
    + code_bytes = simple_strtoul(s, NULL, 0);
    + if (code_bytes > 8192)
    + code_bytes = 8192;
    +
    + return 1;
    +}
    +__setup("code_bytes=", code_bytes_setup);
    diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
    index f9513d6..c47841e 100644
    --- a/arch/x86/kernel/traps_64.c
    +++ b/arch/x86/kernel/traps_64.c
    @@ -55,11 +55,7 @@

    #include <mach_traps.h>

    -int panic_on_unrecovered_nmi;
    -int kstack_depth_to_print = 12;
    -static unsigned int code_bytes = 64;
    static int ignore_nmis;
    -static int die_counter;

    static inline void conditional_sti(struct pt_regs *regs)
    {
    @@ -83,522 +79,6 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
    dec_preempt_count();
    }

    -void printk_address(unsigned long address, int reliable)
    -{
    - printk(" [<%016lx>] %s%pS\n",
    - address, reliable ? "" : "? ", (void *) address);
    -}
    -
    -static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
    - unsigned *usedp, char **idp)
    -{
    - static char ids[][8] = {
    - [DEBUG_STACK - 1] = "#DB",
    - [NMI_STACK - 1] = "NMI",
    - [DOUBLEFAULT_STACK - 1] = "#DF",
    - [STACKFAULT_STACK - 1] = "#SS",
    - [MCE_STACK - 1] = "#MC",
    -#if DEBUG_STKSZ > EXCEPTION_STKSZ
    - [N_EXCEPTION_STACKS ...
    - N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
    -#endif
    - };
    - unsigned k;
    -
    - /*
    - * Iterate over all exception stacks, and figure out whether
    - * 'stack' is in one of them:
    - */
    - for (k = 0; k < N_EXCEPTION_STACKS; k++) {
    - unsigned long end = per_cpu(orig_ist, cpu).ist[k];
    - /*
    - * Is 'stack' above this exception frame's end?
    - * If yes then skip to the next frame.
    - */
    - if (stack >= end)
    - continue;
    - /*
    - * Is 'stack' above this exception frame's start address?
    - * If yes then we found the right frame.
    - */
    - if (stack >= end - EXCEPTION_STKSZ) {
    - /*
    - * Make sure we only iterate through an exception
    - * stack once. If it comes up for the second time
    - * then there's something wrong going on - just
    - * break out and return NULL:
    - */
    - if (*usedp & (1U << k))
    - break;
    - *usedp |= 1U << k;
    - *idp = ids[k];
    - return (unsigned long *)end;
    - }
    - /*
    - * If this is a debug stack, and if it has a larger size than
    - * the usual exception stacks, then 'stack' might still
    - * be within the lower portion of the debug stack:
    - */
    -#if DEBUG_STKSZ > EXCEPTION_STKSZ
    - if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
    - unsigned j = N_EXCEPTION_STACKS - 1;
    -
    - /*
    - * Black magic. A large debug stack is composed of
    - * multiple exception stack entries, which we
    - * iterate through now. Dont look:
    - */
    - do {
    - ++j;
    - end -= EXCEPTION_STKSZ;
    - ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
    - } while (stack < end - EXCEPTION_STKSZ);
    - if (*usedp & (1U << j))
    - break;
    - *usedp |= 1U << j;
    - *idp = ids[j];
    - return (unsigned long *)end;
    - }
    -#endif
    - }
    - return NULL;
    -}
    -
    -/*
    - * 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;
    -}
    -
    -/* The form of the top of the frame on the stack */
    -struct stack_frame {
    - struct stack_frame *next_frame;
    - unsigned long return_address;
    -};
    -
    -static inline 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)
    -{
    - 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 + 8) {
    - ops->address(data, addr, 1);
    - frame = frame->next_frame;
    - bp = (unsigned long) frame;
    - } else {
    - ops->address(data, addr, bp == 0);
    - }
    - }
    - stack++;
    - }
    - return bp;
    -}
    -
    -void dump_trace(struct task_struct *task, struct pt_regs *regs,
    - unsigned long *stack, unsigned long bp,
    - const struct stacktrace_ops *ops, void *data)
    -{
    - const unsigned cpu = get_cpu();
    - unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
    - unsigned used = 0;
    - struct thread_info *tinfo;
    -
    - if (!task)
    - task = current;
    -
    - if (!stack) {
    - unsigned long dummy;
    - stack = &dummy;
    - if (task && task != current)
    - stack = (unsigned long *)task->thread.sp;
    - }
    -
    -#ifdef CONFIG_FRAME_POINTER
    - if (!bp) {
    - if (task == current) {
    - /* Grab bp right from our regs */
    - asm("movq %%rbp, %0" : "=r" (bp) : );
    - } else {
    - /* bp is the last reg pushed by switch_to */
    - bp = *(unsigned long *) task->thread.sp;
    - }
    - }
    -#endif
    -
    - /*
    - * Print function call entries in all stacks, starting at the
    - * current stack address. If the stacks consist of nested
    - * exceptions
    - */
    - tinfo = task_thread_info(task);
    - for (;;) {
    - char *id;
    - unsigned long *estack_end;
    - estack_end = in_exception_stack(cpu, (unsigned long)stack,
    - &used, &id);
    -
    - if (estack_end) {
    - if (ops->stack(data, id) < 0)
    - break;
    -
    - bp = print_context_stack(tinfo, stack, bp, ops,
    - data, estack_end);
    - ops->stack(data, "<EOE>");
    - /*
    - * We link to the next stack via the
    - * second-to-last pointer (index -2 to end) in the
    - * exception stack:
    - */
    - stack = (unsigned long *) estack_end[-2];
    - continue;
    - }
    - if (irqstack_end) {
    - unsigned long *irqstack;
    - irqstack = irqstack_end -
    - (IRQSTACKSIZE - 64) / sizeof(*irqstack);
    -
    - if (stack >= irqstack && stack < irqstack_end) {
    - if (ops->stack(data, "IRQ") < 0)
    - break;
    - bp = print_context_stack(tinfo, stack, bp,
    - ops, data, irqstack_end);
    - /*
    - * We link to the next stack (which would be
    - * the process stack normally) the last
    - * pointer (index -1 to end) in the IRQ stack:
    - */
    - stack = (unsigned long *) (irqstack_end[-1]);
    - irqstack_end = NULL;
    - ops->stack(data, "EOI");
    - continue;
    - }
    - }
    - break;
    - }
    -
    - /*
    - * This handles the process stack:
    - */
    - bp = print_context_stack(tinfo, stack, bp, ops, data, NULL);
    - put_cpu();
    -}
    -EXPORT_SYMBOL(dump_trace);
    -
    -static void
    -print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
    -{
    - print_symbol(msg, symbol);
    - printk("\n");
    -}
    -
    -static void print_trace_warning(void *data, char *msg)
    -{
    - printk("%s\n", msg);
    -}
    -
    -static int print_trace_stack(void *data, char *name)
    -{
    - printk(" <%s> ", name);
    - return 0;
    -}
    -
    -static void print_trace_address(void *data, unsigned long addr, int reliable)
    -{
    - touch_nmi_watchdog();
    - printk_address(addr, reliable);
    -}
    -
    -static const struct stacktrace_ops print_trace_ops = {
    - .warning = print_trace_warning,
    - .warning_symbol = print_trace_warning_symbol,
    - .stack = print_trace_stack,
    - .address = print_trace_address,
    -};
    -
    -static void
    -show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
    - unsigned long *stack, unsigned long bp, char *log_lvl)
    -{
    - printk("Call Trace:\n");
    - 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, "");
    -}
    -
    -static void
    -show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
    - unsigned long *sp, unsigned long bp, char *log_lvl)
    -{
    - unsigned long *stack;
    - int i;
    - const int cpu = smp_processor_id();
    - unsigned long *irqstack_end =
    - (unsigned long *) (cpu_pda(cpu)->irqstackptr);
    - unsigned long *irqstack =
    - (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
    -
    - /*
    - * debugging aid: "show_stack(NULL, NULL);" prints the
    - * back trace for this cpu.
    - */
    -
    - if (sp == NULL) {
    - if (task)
    - sp = (unsigned long *)task->thread.sp;
    - else
    - sp = (unsigned long *)&sp;
    - }
    -
    - stack = sp;
    - for (i = 0; i < kstack_depth_to_print; i++) {
    - if (stack >= irqstack && stack <= irqstack_end) {
    - if (stack == irqstack_end) {
    - stack = (unsigned long *) (irqstack_end[-1]);
    - printk(" <EOI> ");
    - }
    - } else {
    - if (((long) stack & (THREAD_SIZE-1)) == 0)
    - break;
    - }
    - if (i && ((i % 4) == 0))
    - printk("\n");
    - printk(" %016lx", *stack++);
    - touch_nmi_watchdog();
    - }
    - printk("\n");
    - show_trace_log_lvl(task, regs, sp, bp, log_lvl);
    -}
    -
    -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 = 0;
    - unsigned long stack;
    -
    -#ifdef CONFIG_FRAME_POINTER
    - if (!bp)
    - asm("movq %%rbp, %0" : "=r" (bp) : );
    -#endif
    -
    - 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);
    -
    -void show_registers(struct pt_regs *regs)
    -{
    - int i;
    - unsigned long sp;
    - const int cpu = smp_processor_id();
    - struct task_struct *cur = cpu_pda(cpu)->pcurrent;
    -
    - sp = regs->sp;
    - printk("CPU %d ", cpu);
    - __show_regs(regs, 1);
    - printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
    - cur->comm, cur->pid, task_thread_info(cur), cur);
    -
    - /*
    - * When in-kernel, we also print out the stack and code at the
    - * time of the fault..
    - */
    - if (!user_mode(regs)) {
    - unsigned int code_prologue = code_bytes * 43 / 64;
    - unsigned int code_len = code_bytes;
    - unsigned char c;
    - u8 *ip;
    -
    - printk("Stack: ");
    - show_stack_log_lvl(NULL, regs, (unsigned long *)sp,
    - regs->bp, "");
    -
    - printk(KERN_EMERG "Code: ");
    -
    - ip = (u8 *)regs->ip - code_prologue;
    - if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
    - /* try starting at RIP */
    - ip = (u8 *)regs->ip;
    - code_len = code_len - code_prologue + 1;
    - }
    - for (i = 0; i < code_len; i++, ip++) {
    - if (ip < (u8 *)PAGE_OFFSET ||
    - probe_kernel_address(ip, c)) {
    - printk(" Bad RIP value.");
    - break;
    - }
    - if (ip == (u8 *)regs->ip)
    - printk("<%02x> ", c);
    - else
    - printk("%02x ", c);
    - }
    - }
    - printk("\n");
    -}
    -
    -int is_valid_bugaddr(unsigned long ip)
    -{
    - unsigned short ud2;
    -
    - if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2)))
    - return 0;
    -
    - return ud2 == 0x0b0f;
    -}
    -
    -static raw_spinlock_t die_lock = __RAW_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 (!__raw_spin_trylock(&die_lock)) {
    - if (cpu == die_owner)
    - /* nested oops. should stop eventually */;
    - else
    - __raw_spin_lock(&die_lock);
    - }
    - die_nest_count++;
    - die_owner = cpu;
    - console_verbose();
    - bust_spinlocks(1);
    - return flags;
    -}
    -
    -void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
    -{
    - die_owner = -1;
    - bust_spinlocks(0);
    - die_nest_count--;
    - if (!die_nest_count)
    - /* Nest count reaches zero, release the lock. */
    - __raw_spin_unlock(&die_lock);
    - raw_local_irq_restore(flags);
    - if (!regs) {
    - oops_exit();
    - return;
    - }
    - if (in_nmi())
    - panic("Fatal exception in non-maskable interrupt");
    - if (in_interrupt())
    - panic("Fatal exception in interrupt");
    - if (panic_on_oops)
    - panic("Fatal exception");
    - oops_exit();
    - do_exit(signr);
    -}
    -
    -int __kprobes __die(const char *str, struct pt_regs *regs, long err)
    -{
    - printk(KERN_EMERG "%s: %04lx [%u] ", 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_no, SIGSEGV) == NOTIFY_STOP)
    - return 1;
    -
    - show_registers(regs);
    - add_taint(TAINT_DIE);
    - /* Executive summary in case the oops scrolled away */
    - printk(KERN_ALERT "RIP ");
    - printk_address(regs->ip, 1);
    - printk(" RSP <%016lx>\n", regs->sp);
    - if (kexec_should_crash(current))
    - crash_kexec(regs);
    - return 0;
    -}
    -
    -void die(const char *str, struct pt_regs *regs, long err)
    -{
    - unsigned long flags = oops_begin();
    -
    - if (!user_mode(regs))
    - report_bug(regs->ip, regs);
    -
    - if (__die(str, regs, err))
    - regs = NULL;
    - oops_end(flags, regs, SIGSEGV);
    -}
    -
    -notrace __kprobes void
    -die_nmi(char *str, struct pt_regs *regs, int do_panic)
    -{
    - unsigned long flags;
    -
    - if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
    - return;
    -
    - flags = oops_begin();
    - /*
    - * We are in trouble anyway, lets at least try
    - * to get a message out.
    - */
    - printk(KERN_EMERG "%s", str);
    - printk(" on CPU%d, ip %08lx, registers:\n",
    - smp_processor_id(), regs->ip);
    - show_registers(regs);
    - if (kexec_should_crash(current))
    - crash_kexec(regs);
    - if (do_panic || panic_on_oops)
    - panic("Non maskable interrupt");
    - oops_end(flags, NULL, SIGBUS);
    - nmi_exit();
    - local_irq_enable();
    - do_exit(SIGBUS);
    -}
    -
    static void __kprobes
    do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
    long error_code, siginfo_t *info)
    @@ -1187,32 +667,3 @@ void __init trap_init(void)
    */
    cpu_init();
    }
    -
    -static int __init oops_setup(char *s)
    -{
    - if (!s)
    - return -EINVAL;
    - if (!strcmp(s, "panic"))
    - panic_on_oops = 1;
    - return 0;
    -}
    -early_param("oops", oops_setup);
    -
    -static int __init kstack_setup(char *s)
    -{
    - if (!s)
    - return -EINVAL;
    - kstack_depth_to_print = simple_strtoul(s, NULL, 0);
    - return 0;
    -}
    -early_param("kstack", kstack_setup);
    -
    -static int __init code_bytes_setup(char *s)
    -{
    - code_bytes = simple_strtoul(s, NULL, 0);
    - if (code_bytes > 8192)
    - code_bytes = 8192;
    -
    - return 1;
    -}
    -__setup("code_bytes=", code_bytes_setup);
    --
    1.5.4.3


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