X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fx86_64%2Fkernel%2Ftraps-xen.c;h=a551b73a3b007c12afebc89fa6c83856be14a984;hb=e8e9568327cd6722d116bcaabda81f718d451939;hp=457a27616a713d2924f2c25127701e353a76d247;hpb=b8a110738d6eead9db88372cd9385d49347e4ee1;p=linux-2.6.git diff --git a/arch/x86_64/kernel/traps-xen.c b/arch/x86_64/kernel/traps-xen.c index 457a27616..a551b73a3 100644 --- a/arch/x86_64/kernel/traps-xen.c +++ b/arch/x86_64/kernel/traps-xen.c @@ -6,15 +6,12 @@ * * Pentium III FXSR, SSE support * Gareth Hughes , 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 #include #include #include @@ -31,6 +28,7 @@ #include #include #include +#include #include #include @@ -41,12 +39,13 @@ #include #include #include - +#include #include #include #include #include #include +#include asmlinkage void divide_error(void); asmlinkage void debug(void); @@ -72,18 +71,20 @@ asmlinkage void spurious_interrupt_bug(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) { @@ -102,38 +103,49 @@ static inline void preempt_conditional_cli(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 -int printk_address(unsigned long address) -{ +# include +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] = { @@ -148,32 +160,68 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack, }; 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; @@ -191,6 +239,25 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack, 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 @@ -198,25 +265,62 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long 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 \ @@ -225,20 +329,31 @@ void show_trace(unsigned long *stack) * 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(" "); + ops->stack(data, ""); + /* + * 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; } @@ -248,23 +363,71 @@ void show_trace(unsigned long *stack) (IRQSTACKSIZE - 64) / sizeof(*irqstack); if (stack >= irqstack && stack < irqstack_end) { - i += printk(" "); + 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(" "); + 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; @@ -294,11 +457,16 @@ void show_stack(struct task_struct *tsk, unsigned long * rsp) 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); } /* @@ -307,7 +475,7 @@ void show_stack(struct task_struct *tsk, unsigned long * rsp) void dump_stack(void) { unsigned long dummy; - show_trace(&dummy); + show_trace(NULL, NULL, &dummy); } EXPORT_SYMBOL(dump_stack); @@ -324,8 +492,9 @@ void show_registers(struct pt_regs *regs) 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 @@ -334,7 +503,7 @@ void show_registers(struct pt_regs *regs) 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) @@ -421,7 +590,7 @@ void __kprobes oops_end(unsigned long flags) /* 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) @@ -438,6 +607,9 @@ 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 */ @@ -487,8 +659,6 @@ static void __kprobes do_trap(int trapnr, int signr, char *str, { struct task_struct *tsk = current; - conditional_sti(regs); - tsk->thread.error_code = error_code; tsk->thread.trap_no = trapnr; @@ -525,6 +695,7 @@ asmlinkage void do_##name(struct pt_regs * regs, long error_code) \ 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); \ } @@ -539,6 +710,7 @@ asmlinkage void do_##name(struct pt_regs * regs, long error_code) \ 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); \ } @@ -552,7 +724,17 @@ DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS) 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) { @@ -690,8 +872,9 @@ asmlinkage void __kprobes do_int3(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 @@ -753,14 +936,6 @@ asmlinkage void __kprobes do_debug(struct pt_regs * regs, */ 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 */ @@ -1033,3 +1208,18 @@ static int __init kstack_setup(char *s) } __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