#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/nmi.h>
#include <asm/system.h>
#include <asm/uaccess.h>
}
#endif
-unsigned long *in_exception_stack(int cpu, unsigned long stack)
-{
- int k;
+static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
+ unsigned *usedp, const char **idp)
+{
+ static const char ids[N_EXCEPTION_STACKS][8] = {
+ [DEBUG_STACK - 1] = "#DB",
+ [NMI_STACK - 1] = "NMI",
+ [DOUBLEFAULT_STACK - 1] = "#DF",
+ [STACKFAULT_STACK - 1] = "#SS",
+ [MCE_STACK - 1] = "#MC",
+ };
+ unsigned k;
+
for (k = 0; k < N_EXCEPTION_STACKS; k++) {
- struct tss_struct *tss = &per_cpu(init_tss, cpu);
- unsigned long start = tss->ist[k] - EXCEPTION_STKSZ;
+ unsigned long end;
- if (stack >= start && stack < tss->ist[k])
- return (unsigned long *)tss->ist[k];
+ end = per_cpu(init_tss, cpu).ist[k];
+ if (stack >= end)
+ continue;
+ if (stack >= end - EXCEPTION_STKSZ) {
+ if (*usedp & (1U << k))
+ break;
+ *usedp |= 1U << k;
+ *idp = ids[k];
+ return (unsigned long *)end;
+ }
}
return NULL;
-}
+}
/*
* x86-64 can have upto three kernel stacks:
* process stack
* interrupt stack
- * severe exception (double fault, nmi, stack fault) hardware stack
- * Check and process them in order.
+ * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
*/
void show_trace(unsigned long *stack)
{
unsigned long addr;
- unsigned long *irqstack, *irqstack_end, *estack_end;
- const int cpu = safe_smp_processor_id();
+ const unsigned cpu = safe_smp_processor_id();
+ unsigned long *irqstack_end = (unsigned long *)cpu_pda[cpu].irqstackptr;
int i;
+ unsigned used = 0;
printk("\nCall Trace:");
- i = 0;
-
- estack_end = in_exception_stack(cpu, (unsigned long)stack);
- if (estack_end) {
- while (stack < estack_end) {
- addr = *stack++;
- if (__kernel_text_address(addr)) {
- i += printk_address(addr);
- i += printk(" ");
- if (i > 50) {
- printk("\n");
- i = 0;
- }
- }
+
+#define HANDLE_STACK(cond) \
+ do while (cond) { \
+ addr = *stack++; \
+ if (kernel_text_address(addr)) { \
+ /* \
+ * If the address is either in the text segment of the \
+ * kernel, or in the region which contains vmalloc'ed \
+ * memory, it *may* be the address of a calling \
+ * routine; if so, print it so that someone tracing \
+ * down the cause of the crash will be able to figure \
+ * out the call path that was taken. \
+ */ \
+ i += printk_address(addr); \
+ if (i > 50) { \
+ printk("\n "); \
+ i = 0; \
+ } \
+ else \
+ i += printk(" "); \
+ } \
+ } while (0)
+
+ for(i = 0; ; ) {
+ const char *id;
+ unsigned long *estack_end;
+ estack_end = in_exception_stack(cpu, (unsigned long)stack,
+ &used, &id);
+
+ if (estack_end) {
+ i += printk(" <%s> ", id);
+ HANDLE_STACK (stack < estack_end);
+ i += printk(" <EOE> ");
+ stack = (unsigned long *) estack_end[-2];
+ continue;
}
- i += printk(" <EOE> ");
- i += 7;
- stack = (unsigned long *) estack_end[-2];
- }
-
- irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
- irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE + 64);
-
- if (stack >= irqstack && stack < irqstack_end) {
- printk("<IRQ> ");
- while (stack < irqstack_end) {
- addr = *stack++;
- /*
- * If the address is either in the text segment of the
- * kernel, or in the region which contains vmalloc'ed
- * memory, it *may* be the address of a calling
- * routine; if so, print it so that someone tracing
- * down the cause of the crash will be able to figure
- * out the call path that was taken.
- */
- if (__kernel_text_address(addr)) {
- i += printk_address(addr);
- i += printk(" ");
- if (i > 50) {
- printk("\n ");
- i = 0;
- }
+ if (irqstack_end) {
+ unsigned long *irqstack;
+ irqstack = irqstack_end -
+ (IRQSTACKSIZE - 64) / sizeof(*irqstack);
+
+ if (stack >= irqstack && stack < irqstack_end) {
+ i += printk(" <IRQ> ");
+ HANDLE_STACK (stack < irqstack_end);
+ stack = (unsigned long *) (irqstack_end[-1]);
+ irqstack_end = NULL;
+ i += printk(" <EOI> ");
+ continue;
}
- }
- stack = (unsigned long *) (irqstack_end[-1]);
- printk(" <EOI> ");
- i += 7;
- }
-
- while (((long) stack & (THREAD_SIZE-1)) != 0) {
- addr = *stack++;
- if (__kernel_text_address(addr)) {
- i += printk_address(addr);
- i += printk(" ");
- if (i > 50) {
- printk("\n ");
- i = 0;
- }
}
+ break;
}
+
+ HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
+#undef HANDLE_STACK
printk("\n");
}
if (i && ((i % 4) == 0))
printk("\n ");
printk("%016lx ", *stack++);
+ touch_nmi_watchdog();
}
show_trace((unsigned long *)rsp);
}
void show_registers(struct pt_regs *regs)
{
int i;
- int in_kernel = (regs->cs & 3) == 0;
+ int in_kernel = !user_mode(regs);
unsigned long rsp;
const int cpu = safe_smp_processor_id();
struct task_struct *cur = cpu_pda[cpu].pcurrent;
struct bug_frame f;
char tmp;
- if (regs->cs & 3)
+ if (user_mode(regs))
return;
if (__copy_from_user(&f, (struct bug_frame *) regs->rip,
sizeof(struct bug_frame)))
printk(KERN_ALERT "Kernel BUG at %.50s:%d\n", f.filename, f.line);
}
+#ifdef CONFIG_BUG
void out_of_line_bug(void)
{
BUG();
}
+#endif
static DEFINE_SPINLOCK(die_lock);
static int die_owner = -1;
}
#endif
- if ((regs->cs & 3) != 0) {
+ if (user_mode(regs)) {
struct task_struct *tsk = current;
if (exception_trace && unhandled_signal(tsk, signr))
DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
DO_ERROR(18, SIGSEGV, "reserved", reserved)
-
-#define DO_ERROR_STACK(trapnr, signr, str, name) \
-asmlinkage void *do_##name(struct pt_regs * regs, long error_code) \
-{ \
- struct pt_regs *pr = ((struct pt_regs *)(current->thread.rsp0))-1; \
- if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
- == NOTIFY_STOP) \
- return regs; \
- if (regs->cs & 3) { \
- memcpy(pr, regs, sizeof(struct pt_regs)); \
- regs = pr; \
- } \
- do_trap(trapnr, signr, str, regs, error_code, NULL); \
- return regs; \
-}
-
-DO_ERROR_STACK(12, SIGBUS, "stack segment", stack_segment)
-DO_ERROR_STACK( 8, SIGSEGV, "double fault", double_fault)
+DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
+DO_ERROR( 8, SIGSEGV, "double fault", double_fault)
asmlinkage void do_general_protection(struct pt_regs * regs, long error_code)
{
}
#endif
- if ((regs->cs & 3)!=0) {
+ if (user_mode(regs)) {
struct task_struct *tsk = current;
if (exception_trace && unhandled_signal(tsk, SIGSEGV))
printk("Do you have a strange power saving mode enabled?\n");
}
+/* Runs on IST stack. This code must keep interrupts off all the time.
+ Nested NMIs are prevented by the CPU. */
asmlinkage void default_do_nmi(struct pt_regs *regs)
{
unsigned char reason = 0;
+ int cpu;
+
+ cpu = smp_processor_id();
/* Only the BSP gets external NMIs from the system. */
- if (!smp_processor_id())
+ if (!cpu)
reason = get_nmi_reason();
if (!(reason & 0xc0)) {
return;
}
+/* Help handler running on IST stack to switch back to user stack
+ for scheduling or signal handling. The actual stack switch is done in
+ entry.S */
+asmlinkage struct pt_regs *sync_regs(struct pt_regs *eregs)
+{
+ struct pt_regs *regs = eregs;
+ /* Did already sync */
+ if (eregs == (struct pt_regs *)eregs->rsp)
+ ;
+ /* Exception from user space */
+ else if (user_mode(eregs))
+ regs = ((struct pt_regs *)current->thread.rsp0) - 1;
+ /* Exception from kernel and interrupts are enabled. Move to
+ kernel process stack. */
+ else if (eregs->eflags & X86_EFLAGS_IF)
+ regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
+ if (eregs != regs)
+ *regs = *eregs;
+ return regs;
+}
+
/* runs on IST stack. */
-asmlinkage void *do_debug(struct pt_regs * regs, unsigned long error_code)
+asmlinkage void do_debug(struct pt_regs * regs, unsigned long error_code)
{
- struct pt_regs *pr;
unsigned long condition;
struct task_struct *tsk = current;
siginfo_t info;
- pr = (struct pt_regs *)(current->thread.rsp0)-1;
- if (regs->cs & 3) {
- memcpy(pr, regs, sizeof(struct pt_regs));
- regs = pr;
- }
-
#ifdef CONFIG_CHECKING
{
/* RED-PEN interaction with debugger - could destroy gs */
}
#endif
- asm("movq %%db6,%0" : "=r" (condition));
+ get_debugreg(condition, 6);
if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
- SIGTRAP) == NOTIFY_STOP) {
- return regs;
- }
+ SIGTRAP) == NOTIFY_STOP)
+ return;
+
conditional_sti(regs);
/* Mask out spurious debug traps due to lazy DR7 setting */
tsk->thread.debugreg6 = condition;
/* Mask out spurious TF errors due to lazy TF clearing */
- if ((condition & DR_STEP) &&
- (notify_die(DIE_DEBUGSTEP, "debugstep", regs, condition,
- 1, SIGTRAP) != NOTIFY_STOP)) {
+ if (condition & DR_STEP) {
/*
* The TF error should be masked out only if the current
* process is not traced and if the TRAP flag has been set
* allowing programs to debug themselves without the ptrace()
* interface.
*/
- if ((regs->cs & 3) == 0)
+ if (!user_mode(regs))
goto clear_TF_reenable;
- if ((tsk->ptrace & (PT_DTRACE|PT_PTRACED)) == PT_DTRACE)
- goto clear_TF;
+ /*
+ * Was the TF flag set by a debugger? If so, clear it now,
+ * so that register information is correct.
+ */
+ if (tsk->ptrace & PT_DTRACE) {
+ regs->eflags &= ~TF_MASK;
+ tsk->ptrace &= ~PT_DTRACE;
+ }
}
/* Ok, finally something we can handle */
info.si_signo = SIGTRAP;
info.si_errno = 0;
info.si_code = TRAP_BRKPT;
- if ((regs->cs & 3) == 0)
+ if (!user_mode(regs))
goto clear_dr7;
info.si_addr = (void __user *)regs->rip;
force_sig_info(SIGTRAP, &info, tsk);
clear_dr7:
- asm volatile("movq %0,%%db7"::"r"(0UL));
- notify_die(DIE_DEBUG, "debug", regs, condition, 1, SIGTRAP);
- return regs;
+ set_debugreg(0UL, 7);
+ return;
clear_TF_reenable:
set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
-
-clear_TF:
- /* RED-PEN could cause spurious errors */
- if (notify_die(DIE_DEBUG, "debug2", regs, condition, 1, SIGTRAP)
- != NOTIFY_STOP)
regs->eflags &= ~TF_MASK;
- return regs;
}
static int kernel_math_error(struct pt_regs *regs, char *str)
return 1;
}
notify_die(DIE_GPF, str, regs, 0, 16, SIGFPE);
-#if 0
- /* This should be a die, but warn only for now */
+ /* Illegal floating point operation in the kernel */
die(str, regs, 0);
-#else
- printk(KERN_DEBUG "%s: %s at ", current->comm, str);
- printk_address(regs->rip);
- printk("\n");
-#endif
return 0;
}
unsigned short cwd, swd;
conditional_sti(regs);
- if ((regs->cs & 3) == 0 &&
+ if (!user_mode(regs) &&
kernel_math_error(regs, "kernel x87 math error"))
return;
unsigned short mxcsr;
conditional_sti(regs);
- if ((regs->cs & 3) == 0 &&
- kernel_math_error(regs, "simd math error"))
+ if (!user_mode(regs) &&
+ kernel_math_error(regs, "kernel simd math error"))
return;
/*