*
* Pentium III FXSR, SSE support
* Gareth Hughes <gareth@valinux.com>, May 2000
- *
- * $Id: traps.c,v 1.36 2002/03/24 11:09:10 ak Exp $
*/
/*
* 'Traps.c' handles hardware traps and faults after we have saved some
* state in 'entry.S'.
*/
-#include <linux/config.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/nmi.h>
#include <linux/kprobes.h>
#include <linux/kexec.h>
+#include <linux/unwind.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/i387.h>
#include <asm/kdebug.h>
#include <asm/processor.h>
-
+#include <asm/unwind.h>
#include <asm/smp.h>
#include <asm/pgalloc.h>
#include <asm/pda.h>
#include <asm/proto.h>
#include <asm/nmi.h>
+#include <asm/stacktrace.h>
asmlinkage void divide_error(void);
asmlinkage void debug(void);
ATOMIC_NOTIFIER_HEAD(die_chain);
+extern char last_sysfs_file[];
+
int register_die_notifier(struct notifier_block *nb)
{
vmalloc_sync_all();
return atomic_notifier_chain_register(&die_chain, nb);
}
-EXPORT_SYMBOL(register_die_notifier);
+EXPORT_SYMBOL(register_die_notifier); /* used modular by kdb */
int unregister_die_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&die_chain, nb);
}
-EXPORT_SYMBOL(unregister_die_notifier);
+EXPORT_SYMBOL(unregister_die_notifier); /* used modular by kdb */
static inline void conditional_sti(struct pt_regs *regs)
{
{
if (regs->eflags & X86_EFLAGS_IF)
local_irq_disable();
+ /* Make sure to not schedule here because we could be running
+ on an exception stack. */
preempt_enable_no_resched();
}
static int kstack_depth_to_print = 10;
+#ifdef CONFIG_STACK_UNWIND
+static int call_trace = 1;
+#else
+#define call_trace (-1)
+#endif
+
#ifdef CONFIG_KALLSYMS
-#include <linux/kallsyms.h>
-int printk_address(unsigned long address)
-{
+# include <linux/kallsyms.h>
+void printk_address(unsigned long address)
+{
unsigned long offset = 0, symsize;
const char *symname;
char *modname;
- char *delim = ":";
+ char *delim = ":";
char namebuf[128];
- symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);
- if (!symname)
- return printk("[<%016lx>]", address);
- if (!modname)
+ symname = kallsyms_lookup(address, &symsize, &offset,
+ &modname, namebuf);
+ if (!symname) {
+ printk(" [<%016lx>]\n", address);
+ return;
+ }
+ if (!modname)
modname = delim = "";
- return printk("<%016lx>{%s%s%s%s%+ld}",
- address, delim, modname, delim, symname, offset);
-}
+ printk(" [<%016lx>] %s%s%s%s+0x%lx/0x%lx\n",
+ address, delim, modname, delim, symname, offset, symsize);
+}
#else
-int printk_address(unsigned long address)
-{
- return printk("[<%016lx>]", address);
-}
+void printk_address(unsigned long address)
+{
+ printk(" [<%016lx>]\n", address);
+}
#endif
static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
- unsigned *usedp, const char **idp)
+ unsigned *usedp, char **idp)
{
#ifndef CONFIG_X86_NO_TSS
static char ids[][8] = {
};
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;
+ /*
+ * set 'end' to the end of the exception stack.
+ */
switch (k + 1) {
+ /*
+ * TODO: this block is not needed i think, because
+ * setup64.c:cpu_init() sets up t->ist[DEBUG_STACK]
+ * properly too.
+ */
#if DEBUG_STKSZ > EXCEPTION_STKSZ
case DEBUG_STACK:
end = cpu_pda(cpu)->debugstack + DEBUG_STKSZ;
break;
#endif
default:
- end = per_cpu(init_tss, cpu).ist[k];
+ end = per_cpu(orig_tss, cpu).ist[k];
break;
}
+ /*
+ * 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;
return NULL;
}
+struct ops_and_data {
+ struct stacktrace_ops *ops;
+ void *data;
+};
+
+static int dump_trace_unwind(struct unwind_frame_info *info, void *context)
+{
+ struct ops_and_data *oad = (struct ops_and_data *)context;
+ int n = 0;
+
+ while (unwind(info) == 0 && UNW_PC(info)) {
+ if (arch_unw_user_mode(info))
+ break;
+ n++;
+ oad->ops->address(oad->data, UNW_PC(info));
+ }
+ return n;
+}
+
/*
* x86-64 can have upto three kernel stacks:
* process stack
* severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
*/
-void show_trace(unsigned long *stack)
+void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * stack,
+ struct stacktrace_ops *ops, void *data)
{
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:");
+ if (!tsk)
+ tsk = current;
+
+ if (call_trace >= 0) {
+ int unw_ret = 0;
+ struct unwind_frame_info info;
+ struct ops_and_data oad = { .ops = ops, .data = data };
+
+ if (regs) {
+ if (unwind_init_frame_info(&info, tsk, regs) == 0)
+ unw_ret = dump_trace_unwind(&info, &oad);
+ } else if (tsk == current)
+ unw_ret = unwind_init_running(&info, dump_trace_unwind, &oad);
+ else {
+ if (unwind_init_blocked(&info, tsk) == 0)
+ unw_ret = dump_trace_unwind(&info, &oad);
+ }
+ if (unw_ret > 0) {
+ if (call_trace == 1 && !arch_unw_user_mode(&info)) {
+ ops->warning_symbol(data, "DWARF2 unwinder stuck at %s\n",
+ UNW_PC(&info));
+ if ((long)UNW_SP(&info) < 0) {
+ ops->warning(data, "Leftover inexact backtrace:\n");
+ stack = (unsigned long *)UNW_SP(&info);
+ } else
+ ops->warning(data, "Full inexact backtrace again:\n");
+ } else if (call_trace >= 1)
+ return;
+ else
+ ops->warning(data, "Full inexact backtrace again:\n");
+ } else
+ ops->warning(data, "Inexact backtrace:\n");
+ }
+ if (!stack) {
+ unsigned long dummy;
+ stack = &dummy;
+ if (tsk && tsk != current)
+ stack = (unsigned long *)tsk->thread.rsp;
+ }
+ /*
+ * Print function call entries within a stack. 'cond' is the
+ * "end of stackframe" condition, that the 'stack++'
+ * iteration will eventually trigger.
+ */
#define HANDLE_STACK(cond) \
do while (cond) { \
unsigned long addr = *stack++; \
if (kernel_text_address(addr)) { \
- if (i > 50) { \
- printk("\n "); \
- i = 0; \
- } \
- else \
- i += printk(" "); \
/* \
* If the address is either in the text segment of the \
* kernel, or in the region which contains vmalloc'ed \
* down the cause of the crash will be able to figure \
* out the call path that was taken. \
*/ \
- i += printk_address(addr); \
+ ops->address(data, addr); \
} \
} while (0)
- for(i = 11; ; ) {
- const char *id;
+ /*
+ * Print function call entries in all stacks, starting at the
+ * current stack address. If the stacks consist of nested
+ * exceptions
+ */
+ for (;;) {
+ char *id;
unsigned long *estack_end;
estack_end = in_exception_stack(cpu, (unsigned long)stack,
&used, &id);
if (estack_end) {
- i += printk(" <%s>", id);
+ if (ops->stack(data, id) < 0)
+ break;
HANDLE_STACK (stack < estack_end);
- i += printk(" <EOE>");
+ 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;
}
(IRQSTACKSIZE - 64) / sizeof(*irqstack);
if (stack >= irqstack && stack < irqstack_end) {
- i += printk(" <IRQ>");
+ if (ops->stack(data, "IRQ") < 0)
+ break;
HANDLE_STACK (stack < 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;
- i += printk(" <EOI>");
+ ops->stack(data, "EOI");
continue;
}
}
break;
}
+ /*
+ * This handles the process stack:
+ */
HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
#undef HANDLE_STACK
+}
+EXPORT_SYMBOL(dump_trace);
+
+static void
+print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
+{
+ print_symbol(msg, symbol);
printk("\n");
}
-void show_stack(struct task_struct *tsk, unsigned long * rsp)
+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)
+{
+ printk_address(addr);
+}
+
+static 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(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack)
+{
+ printk("\nCall Trace:\n");
+ dump_trace(tsk, regs, stack, &print_trace_ops, NULL);
+ printk("\n");
+}
+
+static void
+_show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *rsp)
{
unsigned long *stack;
int i;
break;
}
if (i && ((i % 4) == 0))
- printk("\n ");
- printk("%016lx ", *stack++);
+ printk("\n");
+ printk(" %016lx ", *stack++);
touch_nmi_watchdog();
}
- show_trace((unsigned long *)rsp);
+ show_trace(tsk, regs, rsp);
+}
+
+void show_stack(struct task_struct *tsk, unsigned long * rsp)
+{
+ _show_stack(tsk, NULL, rsp);
}
/*
void dump_stack(void)
{
unsigned long dummy;
- show_trace(&dummy);
+ show_trace(NULL, NULL, &dummy);
}
EXPORT_SYMBOL(dump_stack);
printk("CPU %d ", cpu);
__show_regs(regs);
- printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
- cur->comm, cur->pid, task_thread_info(cur), cur);
+ printk("Process %s (pid: %d[#%u], threadinfo %p, task %p)\n",
+ cur->comm, cur->pid, cur->xid,
+ task_thread_info(cur), cur);
/*
* When in-kernel, we also print out the stack and code at the
if (in_kernel) {
printk("Stack: ");
- show_stack(NULL, (unsigned long*)rsp);
+ _show_stack(NULL, regs, (unsigned long*)rsp);
printk("\nCode: ");
if (regs->rip < PAGE_OFFSET)
/* Nest count reaches zero, release the lock. */
spin_unlock_irqrestore(&die_lock, flags);
if (panic_on_oops)
- panic("Oops");
+ panic("Fatal exception");
}
void __kprobes __die(const char * str, struct pt_regs * regs, long err)
printk("DEBUG_PAGEALLOC");
#endif
printk("\n");
+#ifdef CONFIG_SYSFS
+ printk(KERN_ALERT "last sysfs file: %s\n", last_sysfs_file);
+#endif
notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
show_registers(regs);
/* Executive summary in case the oops scrolled away */
{
struct task_struct *tsk = current;
- conditional_sti(regs);
-
tsk->thread.error_code = error_code;
tsk->thread.trap_no = trapnr;
if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
== NOTIFY_STOP) \
return; \
+ conditional_sti(regs); \
do_trap(trapnr, signr, str, regs, error_code, NULL); \
}
if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
== NOTIFY_STOP) \
return; \
+ conditional_sti(regs); \
do_trap(trapnr, signr, str, regs, error_code, &info); \
}
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)
-DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
+
+/* Runs on IST stack */
+asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code)
+{
+ if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
+ 12, SIGBUS) == NOTIFY_STOP)
+ return;
+ preempt_conditional_sti(regs);
+ do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
+ preempt_conditional_cli(regs);
+}
asmlinkage void do_double_fault(struct pt_regs * regs, long error_code)
{
if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
return;
}
+ preempt_conditional_sti(regs);
do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
- return;
+ preempt_conditional_cli(regs);
}
/* Help handler running on IST stack to switch back to user stack
*/
if (!user_mode(regs))
goto clear_TF_reenable;
- /*
- * 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 */
}
__setup("kstack=", kstack_setup);
+#ifdef CONFIG_STACK_UNWIND
+static int __init call_trace_setup(char *s)
+{
+ if (strcmp(s, "old") == 0)
+ call_trace = -1;
+ else if (strcmp(s, "both") == 0)
+ call_trace = 0;
+ else if (strcmp(s, "newfallback") == 0)
+ call_trace = 1;
+ else if (strcmp(s, "new") == 0)
+ call_trace = 2;
+ return 1;
+}
+__setup("call_trace=", call_trace_setup);
+#endif
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