Release 4.15 arch/x86/kernel/dumpstack.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/sched/debug.h>
#include <linux/sched/task_stack.h>
#include <linux/ftrace.h>
#include <linux/kexec.h>
#include <linux/bug.h>
#include <linux/nmi.h>
#include <linux/sysfs.h>
#include <asm/cpu_entry_area.h>
#include <asm/stacktrace.h>
#include <asm/unwind.h>
int panic_on_unrecovered_nmi;
int panic_on_io_nmi;
unsigned int code_bytes = 64;
static int die_counter;
bool in_task_stack(unsigned long *stack, struct task_struct *task,
struct stack_info *info)
{
unsigned long *begin = task_stack_page(task);
unsigned long *end = task_stack_page(task) + THREAD_SIZE;
if (stack < begin || stack >= end)
return false;
info->type = STACK_TYPE_TASK;
info->begin = begin;
info->end = end;
info->next_sp = NULL;
return true;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Josh Poimboeuf | 82 | 100.00% | 1 | 100.00% |
| Total | 82 | 100.00% | 1 | 100.00% |
bool in_entry_stack(unsigned long *stack, struct stack_info *info)
{
struct entry_stack *ss = cpu_entry_stack(smp_processor_id());
void *begin = ss;
void *end = ss + 1;
if ((void *)stack < begin || (void *)stack >= end)
return false;
info->type = STACK_TYPE_ENTRY;
info->begin = begin;
info->end = end;
info->next_sp = NULL;
return true;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Andrew Lutomirski | 84 | 95.45% | 3 | 75.00% |
| Dave Hansen | 4 | 4.55% | 1 | 25.00% |
| Total | 88 | 100.00% | 4 | 100.00% |
static void printk_stack_address(unsigned long address, int reliable,
char *log_lvl)
{
touch_nmi_watchdog();
printk("%s %s%pB\n", log_lvl, reliable ? "" : "? ", (void *)address);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 26 | 66.67% | 1 | 20.00% |
| Josh Poimboeuf | 7 | 17.95% | 2 | 40.00% |
| Adrien Schildknecht | 4 | 10.26% | 1 | 20.00% |
| Jiri Slaby | 2 | 5.13% | 1 | 20.00% |
| Total | 39 | 100.00% | 5 | 100.00% |
void show_iret_regs(struct pt_regs *regs)
{
printk(KERN_DEFAULT "RIP: %04x:%pS\n", (int)regs->cs, (void *)regs->ip);
printk(KERN_DEFAULT "RSP: %04x:%016lx EFLAGS: %08lx", (int)regs->ss,
regs->sp, regs->flags);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Josh Poimboeuf | 52 | 100.00% | 1 | 100.00% |
| Total | 52 | 100.00% | 1 | 100.00% |
static void show_regs_if_on_stack(struct stack_info *info, struct pt_regs *regs,
bool partial)
{
/*
* These on_stack() checks aren't strictly necessary: the unwind code
* has already validated the 'regs' pointer. The checks are done for
* ordering reasons: if the registers are on the next stack, we don't
* want to print them out yet. Otherwise they'll be shown as part of
* the wrong stack. Later, when show_trace_log_lvl() switches to the
* next stack, this function will be called again with the same regs so
* they can be printed in the right context.
*/
if (!partial && on_stack(info, regs, sizeof(*regs))) {
__show_regs(regs, 0);
} else if (partial && on_stack(info, (void *)regs + IRET_FRAME_OFFSET,
IRET_FRAME_SIZE)) {
/*
* When an interrupt or exception occurs in entry code, the
* full pt_regs might not have been saved yet. In that case
* just print the iret frame.
*/
show_iret_regs(regs);
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Josh Poimboeuf | 75 | 100.00% | 2 | 100.00% |
| Total | 75 | 100.00% | 2 | 100.00% |
void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
unsigned long *stack, char *log_lvl)
{
struct unwind_state state;
struct stack_info stack_info = {0};
unsigned long visit_mask = 0;
int graph_idx = 0;
bool partial;
printk("%sCall Trace:\n", log_lvl);
unwind_start(&state, task, regs, stack);
stack = stack ? : get_stack_pointer(task, regs);
regs = unwind_get_entry_regs(&state, &partial);
/*
* Iterate through the stacks, starting with the current stack pointer.
* Each stack has a pointer to the next one.
*
* x86-64 can have several stacks:
* - task stack
* - interrupt stack
* - HW exception stacks (double fault, nmi, debug, mce)
* - entry stack
*
* x86-32 can have up to four stacks:
* - task stack
* - softirq stack
* - hardirq stack
* - entry stack
*/
for ( ; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) {
const char *stack_name;
if (get_stack_info(stack, task, &stack_info, &visit_mask)) {
/*
* We weren't on a valid stack. It's possible that
* we overflowed a valid stack into a guard page.
* See if the next page up is valid so that we can
* generate some kind of backtrace if this happens.
*/
stack = (unsigned long *)PAGE_ALIGN((unsigned long)stack);
if (get_stack_info(stack, task, &stack_info, &visit_mask))
break;
}
stack_name = stack_type_name(stack_info.type);
if (stack_name)
printk("%s <%s>\n", log_lvl, stack_name);
if (regs)
show_regs_if_on_stack(&stack_info, regs, partial);
/*
* Scan the stack, printing any text addresses we find. At the
* same time, follow proper stack frames with the unwinder.
*
* Addresses found during the scan which are not reported by
* the unwinder are considered to be additional clues which are
* sometimes useful for debugging and are prefixed with '?'.
* This also serves as a failsafe option in case the unwinder
* goes off in the weeds.
*/
for (; stack < stack_info.end; stack++) {
unsigned long real_addr;
int reliable = 0;
unsigned long addr = READ_ONCE_NOCHECK(*stack);
unsigned long *ret_addr_p =
unwind_get_return_address_ptr(&state);
if (!__kernel_text_address(addr))
continue;
/*
* Don't print regs->ip again if it was already printed
* by show_regs_if_on_stack().
*/
if (regs && stack == ®s->ip)
goto next;
if (stack == ret_addr_p)
reliable = 1;
/*
* When function graph tracing is enabled for a
* function, its return address on the stack is
* replaced with the address of an ftrace handler
* (return_to_handler). In that case, before printing
* the "real" address, we want to print the handler
* address as an "unreliable" hint that function graph
* tracing was involved.
*/
real_addr = ftrace_graph_ret_addr(task, &graph_idx,
addr, stack);
if (real_addr != addr)
printk_stack_address(addr, 0, log_lvl);
printk_stack_address(real_addr, reliable, log_lvl);
if (!reliable)
continue;
next:
/*
* Get the next frame from the unwinder. No need to
* check for an error: if anything goes wrong, the rest
* of the addresses will just be printed as unreliable.
*/
unwind_next_frame(&state);
/* if the frame has entry regs, print them */
regs = unwind_get_entry_regs(&state, &partial);
if (regs)
show_regs_if_on_stack(&stack_info, regs, partial);
}
if (stack_name)
printk("%s </%s>\n", log_lvl, stack_name);
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Josh Poimboeuf | 309 | 81.96% | 11 | 64.71% |
| Neil Horman | 39 | 10.34% | 1 | 5.88% |
| Andrew Lutomirski | 23 | 6.10% | 1 | 5.88% |
| Namhyung Kim | 3 | 0.80% | 1 | 5.88% |
| Frédéric Weisbecker | 1 | 0.27% | 1 | 5.88% |
| Dave Hansen | 1 | 0.27% | 1 | 5.88% |
| Adrien Schildknecht | 1 | 0.27% | 1 | 5.88% |
| Total | 377 | 100.00% | 17 | 100.00% |
void show_stack(struct task_struct *task, unsigned long *sp)
{
task = task ? : current;
/*
* Stack frames below this one aren't interesting. Don't show them
* if we're printing for %current.
*/
if (!sp && task == current)
sp = get_stack_pointer(current, NULL);
show_trace_log_lvl(task, NULL, sp, KERN_DEFAULT);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 23 | 44.23% | 1 | 14.29% |
| Josh Poimboeuf | 16 | 30.77% | 5 | 71.43% |
| Tejun Heo | 13 | 25.00% | 1 | 14.29% |
| Total | 52 | 100.00% | 7 | 100.00% |
void show_stack_regs(struct pt_regs *regs)
{
show_trace_log_lvl(current, regs, NULL, KERN_DEFAULT);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Borislav Petkov | 18 | 85.71% | 1 | 25.00% |
| Josh Poimboeuf | 3 | 14.29% | 3 | 75.00% |
| Total | 21 | 100.00% | 4 | 100.00% |
static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
static int die_owner = -1;
static unsigned int die_nest_count;
unsigned 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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 71 | 97.26% | 1 | 50.00% |
| Thomas Gleixner | 2 | 2.74% | 1 | 50.00% |
| Total | 73 | 100.00% | 2 | 100.00% |
EXPORT_SYMBOL_GPL(oops_begin);
NOKPROBE_SYMBOL(oops_begin);
void __noreturn rewind_stack_do_exit(int signr);
void 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, LOCKDEP_NOW_UNRELIABLE);
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");
/*
* We're not going to return, but we might be on an IST stack or
* have very little stack space left. Rewind the stack and kill
* the task.
*/
rewind_stack_do_exit(signr);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 97 | 95.10% | 1 | 25.00% |
| Rusty Russell | 2 | 1.96% | 1 | 25.00% |
| Andrew Lutomirski | 2 | 1.96% | 1 | 25.00% |
| Thomas Gleixner | 1 | 0.98% | 1 | 25.00% |
| Total | 102 | 100.00% | 4 | 100.00% |
NOKPROBE_SYMBOL(oops_end);
int __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]%s%s%s%s%s\n", str, err & 0xffff, ++die_counter,
IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "",
IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",
IS_ENABLED(CONFIG_KASAN) ? " KASAN" : "",
IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION) ?
(boot_cpu_has(X86_FEATURE_PTI) ? " PTI" : " NOPTI") : "");
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(regs)) {
sp = regs->sp;
ss = regs->ss;
} else {
sp = kernel_stack_pointer(regs);
savesegment(ss, ss);
}
printk(KERN_EMERG "EIP: %pS SS:ESP: %04x:%08lx\n",
(void *)regs->ip, ss, sp);
#else
/* Executive summary in case the oops scrolled away */
printk(KERN_ALERT "RIP: %pS RSP: %016lx\n", (void *)regs->ip, regs->sp);
#endif
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 135 | 62.21% | 1 | 8.33% |
| Rasmus Villemoes | 25 | 11.52% | 1 | 8.33% |
| Vlastimil Babka | 19 | 8.76% | 1 | 8.33% |
| H. Peter Anvin | 17 | 7.83% | 1 | 8.33% |
| Josh Poimboeuf | 11 | 5.07% | 1 | 8.33% |
| Jan Beulich | 4 | 1.84% | 2 | 16.67% |
| Christian Bornträger | 2 | 0.92% | 1 | 8.33% |
| Prarit Bhargava | 1 | 0.46% | 1 | 8.33% |
| Andrew Lutomirski | 1 | 0.46% | 1 | 8.33% |
| Andrey Ryabinin | 1 | 0.46% | 1 | 8.33% |
| Srikar Dronamraju | 1 | 0.46% | 1 | 8.33% |
| Total | 217 | 100.00% | 12 | 100.00% |
NOKPROBE_SYMBOL(__die);
/*
* 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 (__die(str, regs, err))
sig = 0;
oops_end(flags, regs, sig);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 54 | 100.00% | 1 | 100.00% |
| Total | 54 | 100.00% | 1 | 100.00% |
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Shuah Khan | 32 | 50.79% | 1 | 50.00% |
| Neil Horman | 31 | 49.21% | 1 | 50.00% |
| Total | 63 | 100.00% | 2 | 100.00% |
__setup("code_bytes=", code_bytes_setup);
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Josh Poimboeuf | 558 | 39.30% | 19 | 35.19% |
| Neil Horman | 553 | 38.94% | 1 | 1.85% |
| Andrew Lutomirski | 118 | 8.31% | 6 | 11.11% |
| Shuah Khan | 32 | 2.25% | 1 | 1.85% |
| Rasmus Villemoes | 25 | 1.76% | 1 | 1.85% |
| Vlastimil Babka | 19 | 1.34% | 1 | 1.85% |
| Borislav Petkov | 18 | 1.27% | 1 | 1.85% |
| H. Peter Anvin | 17 | 1.20% | 1 | 1.85% |
| Masami Hiramatsu | 15 | 1.06% | 1 | 1.85% |
| Tejun Heo | 13 | 0.92% | 1 | 1.85% |
| Thomas Gleixner | 8 | 0.56% | 4 | 7.41% |
| Ingo Molnar | 6 | 0.42% | 2 | 3.70% |
| Huang Ying | 5 | 0.35% | 1 | 1.85% |
| Adrien Schildknecht | 5 | 0.35% | 1 | 1.85% |
| Dave Hansen | 5 | 0.35% | 1 | 1.85% |
| Jan Beulich | 4 | 0.28% | 2 | 3.70% |
| Namhyung Kim | 3 | 0.21% | 1 | 1.85% |
| Kurt Garloff | 3 | 0.21% | 1 | 1.85% |
| Steven Rostedt | 3 | 0.21% | 1 | 1.85% |
| Rusty Russell | 2 | 0.14% | 1 | 1.85% |
| Jiri Slaby | 2 | 0.14% | 1 | 1.85% |
| Christian Bornträger | 2 | 0.14% | 1 | 1.85% |
| Prarit Bhargava | 1 | 0.07% | 1 | 1.85% |
| Srikar Dronamraju | 1 | 0.07% | 1 | 1.85% |
| Andrey Ryabinin | 1 | 0.07% | 1 | 1.85% |
| Frédéric Weisbecker | 1 | 0.07% | 1 | 1.85% |
| Total | 1420 | 100.00% | 54 | 100.00% |
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