kernel-fxtec-pro1x/arch/x86/kernel/dumpstack.c
Kurt Garloff 5211a242d0 x86: Add sysctl to allow panic on IOCK NMI error
This patch introduces a new sysctl:

    /proc/sys/kernel/panic_on_io_nmi

which defaults to 0 (off).

When enabled, the kernel panics when the kernel receives an NMI
caused by an IO error.

The IO error triggered NMI indicates a serious system
condition, which could result in IO data corruption. Rather
than contiuing, panicing and dumping might be a better choice,
so one can figure out what's causing the IO error.

This could be especially important to companies running IO
intensive applications where corruption must be avoided, e.g. a
bank's databases.

[ SuSE has been shipping it for a while, it was done at the
  request of a large database vendor, for their users. ]

Signed-off-by: Kurt Garloff <garloff@suse.de>
Signed-off-by: Roberto Angelino <robertangelino@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
LKML-Reference: <20090624213211.GA11291@kroah.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-25 22:06:11 +02:00

359 lines
7.9 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/ftrace.h>
#include <linux/kexec.h>
#include <linux/bug.h>
#include <linux/nmi.h>
#include <linux/sysfs.h>
#include <linux/ftrace.h>
#include <asm/stacktrace.h>
#include "dumpstack.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)
{
printk(" [<%p>] %s%pS\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 = tinfo->task;
unsigned long ret_addr;
int index = task->curr_ret_stack;
if (addr != (unsigned long)return_to_handler)
return;
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;
}
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,
};
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 = 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);
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;
/* notify the hw-branch tracer so it may disable tracing and
add the last trace to the trace buffer -
the earlier this happens, the more useful the trace. */
trace_hw_branch_oops();
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)
{
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. */
__raw_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_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);
#ifdef CONFIG_X86_32
sp = (unsigned long) (&regs->sp);
savesegment(ss, ss);
if (user_mode(regs)) {
sp = regs->sp;
ss = regs->ss & 0xffff;
}
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);
}
void notrace __kprobes
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;
/*
* We are in trouble anyway, lets at least try
* to get a message out.
*/
flags = oops_begin();
printk(KERN_EMERG "%s", str);
printk(" on CPU%d, ip %08lx, registers:\n",
smp_processor_id(), regs->ip);
show_registers(regs);
oops_end(flags, regs, 0);
if (do_panic || panic_on_oops)
panic("Non maskable interrupt");
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);