![Andrew Morton](/assets/img/avatar_default.png)
Print the name of the last-accessed sysfs file when we oops, to help track down oopses which occur in sysfs store/read handlers. Because these oopses tend to not leave any trace of the offending code in the stack traces. Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
576 lines
13 KiB
C
576 lines
13 KiB
C
/*
|
|
* 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 <linux/sysfs.h>
|
|
|
|
#include <asm/stacktrace.h>
|
|
|
|
#define STACKSLOTS_PER_LINE 4
|
|
#define get_bp(bp) asm("movq %%rbp, %0" : "=r" (bp) :)
|
|
|
|
int panic_on_unrecovered_nmi;
|
|
int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
|
|
static unsigned int code_bytes = 64;
|
|
static int die_counter;
|
|
|
|
void printk_address(unsigned long address, int reliable)
|
|
{
|
|
printk(" [<%p>] %s%pS\n", (void *) 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 + sizeof(long)) {
|
|
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 */
|
|
get_bp(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)
|
|
{
|
|
printk(data);
|
|
print_symbol(msg, symbol);
|
|
printk("\n");
|
|
}
|
|
|
|
static void print_trace_warning(void *data, char *msg)
|
|
{
|
|
printk("%s%s\n", (char *)data, msg);
|
|
}
|
|
|
|
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 = {
|
|
.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("%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, "");
|
|
}
|
|
|
|
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 % STACKSLOTS_PER_LINE) == 0))
|
|
printk("\n%s", log_lvl);
|
|
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)
|
|
get_bp(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(KERN_EMERG "Stack:\n");
|
|
show_stack_log_lvl(NULL, regs, (unsigned long *)sp,
|
|
regs->bp, KERN_EMERG);
|
|
|
|
printk(KERN_EMERG "Code: ");
|
|
|
|
ip = (u8 *)regs->ip - code_prologue;
|
|
if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
|
|
/* try starting at IP */
|
|
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_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 [#%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");
|
|
sysfs_printk_last_file();
|
|
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);
|