[PATCH] IPMI: watchdog handle panic properly
[safe/jmp/linux-2.6] / arch / i386 / kernel / traps.c
index b85c9e8..7846409 100644 (file)
@@ -28,6 +28,7 @@
 #include <linux/utsname.h>
 #include <linux/kprobes.h>
 #include <linux/kexec.h>
+#include <linux/unwind.h>
 
 #ifdef CONFIG_EISA
 #include <linux/ioport.h>
@@ -47,7 +48,7 @@
 #include <asm/desc.h>
 #include <asm/i387.h>
 #include <asm/nmi.h>
-
+#include <asm/unwind.h>
 #include <asm/smp.h>
 #include <asm/arch_hooks.h>
 #include <asm/kdebug.h>
@@ -92,32 +93,51 @@ asmlinkage void spurious_interrupt_bug(void);
 asmlinkage void machine_check(void);
 
 static int kstack_depth_to_print = 24;
-struct notifier_block *i386die_chain;
-static DEFINE_SPINLOCK(die_notifier_lock);
+static int call_trace = 1;
+ATOMIC_NOTIFIER_HEAD(i386die_chain);
 
 int register_die_notifier(struct notifier_block *nb)
 {
-       int err = 0;
-       unsigned long flags;
-       spin_lock_irqsave(&die_notifier_lock, flags);
-       err = notifier_chain_register(&i386die_chain, nb);
-       spin_unlock_irqrestore(&die_notifier_lock, flags);
-       return err;
+       vmalloc_sync_all();
+       return atomic_notifier_chain_register(&i386die_chain, nb);
 }
 EXPORT_SYMBOL(register_die_notifier);
 
+int unregister_die_notifier(struct notifier_block *nb)
+{
+       return atomic_notifier_chain_unregister(&i386die_chain, nb);
+}
+EXPORT_SYMBOL(unregister_die_notifier);
+
 static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
 {
        return  p > (void *)tinfo &&
                p < (void *)tinfo + THREAD_SIZE - 3;
 }
 
-static void print_addr_and_symbol(unsigned long addr, char *log_lvl)
+/*
+ * Print CONFIG_STACK_BACKTRACE_COLS address/symbol entries per line.
+ */
+static inline int print_addr_and_symbol(unsigned long addr, char *log_lvl,
+                                       int printed)
 {
-       printk(log_lvl);
+       if (!printed)
+               printk(log_lvl);
+
+#if CONFIG_STACK_BACKTRACE_COLS == 1
        printk(" [<%08lx>] ", addr);
+#else
+       printk(" <%08lx> ", addr);
+#endif
        print_symbol("%s", addr);
-       printk("\n");
+
+       printed = (printed + 1) % CONFIG_STACK_BACKTRACE_COLS;
+       if (printed)
+               printk(" ");
+       else
+               printk("\n");
+
+       return printed;
 }
 
 static inline unsigned long print_context_stack(struct thread_info *tinfo,
@@ -125,24 +145,50 @@ static inline unsigned long print_context_stack(struct thread_info *tinfo,
                                char *log_lvl)
 {
        unsigned long addr;
+       int printed = 0; /* nr of entries already printed on current line */
 
 #ifdef CONFIG_FRAME_POINTER
        while (valid_stack_ptr(tinfo, (void *)ebp)) {
                addr = *(unsigned long *)(ebp + 4);
-               print_addr_and_symbol(addr, log_lvl);
+               printed = print_addr_and_symbol(addr, log_lvl, printed);
+               /*
+                * break out of recursive entries (such as
+                * end_of_stack_stop_unwind_function):
+                */
+               if (ebp == *(unsigned long *)ebp)
+                       break;
                ebp = *(unsigned long *)ebp;
        }
 #else
        while (valid_stack_ptr(tinfo, stack)) {
                addr = *stack++;
                if (__kernel_text_address(addr))
-                       print_addr_and_symbol(addr, log_lvl);
+                       printed = print_addr_and_symbol(addr, log_lvl, printed);
        }
 #endif
+       if (printed)
+               printk("\n");
+
        return ebp;
 }
 
-static void show_trace_log_lvl(struct task_struct *task,
+static asmlinkage int show_trace_unwind(struct unwind_frame_info *info, void *log_lvl)
+{
+       int n = 0;
+       int printed = 0; /* nr of entries already printed on current line */
+
+       while (unwind(info) == 0 && UNW_PC(info)) {
+               ++n;
+               printed = print_addr_and_symbol(UNW_PC(info), log_lvl, printed);
+               if (arch_unw_user_mode(info))
+                       break;
+       }
+       if (printed)
+               printk("\n");
+       return n;
+}
+
+static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
                               unsigned long *stack, char *log_lvl)
 {
        unsigned long ebp;
@@ -150,6 +196,26 @@ static void show_trace_log_lvl(struct task_struct *task,
        if (!task)
                task = current;
 
+       if (call_trace >= 0) {
+               int unw_ret = 0;
+               struct unwind_frame_info info;
+
+               if (regs) {
+                       if (unwind_init_frame_info(&info, task, regs) == 0)
+                               unw_ret = show_trace_unwind(&info, log_lvl);
+               } else if (task == current)
+                       unw_ret = unwind_init_running(&info, show_trace_unwind, log_lvl);
+               else {
+                       if (unwind_init_blocked(&info, task) == 0)
+                               unw_ret = show_trace_unwind(&info, log_lvl);
+               }
+               if (unw_ret > 0) {
+                       if (call_trace > 0)
+                               return;
+                       printk("%sLegacy call trace:\n", log_lvl);
+               }
+       }
+
        if (task == current) {
                /* Grab ebp right from our regs */
                asm ("movl %%ebp, %0" : "=r" (ebp) : );
@@ -166,18 +232,17 @@ static void show_trace_log_lvl(struct task_struct *task,
                stack = (unsigned long*)context->previous_esp;
                if (!stack)
                        break;
-               printk(log_lvl);
-               printk(" =======================\n");
+               printk("%s =======================\n", log_lvl);
        }
 }
 
-void show_trace(struct task_struct *task, unsigned long * stack)
+void show_trace(struct task_struct *task, struct pt_regs *regs, unsigned long * stack)
 {
-       show_trace_log_lvl(task, stack, "");
+       show_trace_log_lvl(task, regs, stack, "");
 }
 
-static void show_stack_log_lvl(struct task_struct *task, unsigned long *esp,
-                              char *log_lvl)
+static void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+                              unsigned long *esp, char *log_lvl)
 {
        unsigned long *stack;
        int i;
@@ -190,26 +255,21 @@ static void show_stack_log_lvl(struct task_struct *task, unsigned long *esp,
        }
 
        stack = esp;
-       printk(log_lvl);
        for(i = 0; i < kstack_depth_to_print; i++) {
                if (kstack_end(stack))
                        break;
-               if (i && ((i % 8) == 0)) {
-                       printk("\n");
-                       printk(log_lvl);
-                       printk("       ");
-               }
+               if (i && ((i % 8) == 0))
+                       printk("\n%s       ", log_lvl);
                printk("%08lx ", *stack++);
        }
-       printk("\n");
-       printk(log_lvl);
-       printk("Call Trace:\n");
-       show_trace_log_lvl(task, esp, log_lvl);
+       printk("\n%sCall Trace:\n", log_lvl);
+       show_trace_log_lvl(task, regs, esp, log_lvl);
 }
 
 void show_stack(struct task_struct *task, unsigned long *esp)
 {
-       show_stack_log_lvl(task, esp, "");
+       printk("       ");
+       show_stack_log_lvl(task, NULL, esp, "");
 }
 
 /*
@@ -219,7 +279,7 @@ void dump_stack(void)
 {
        unsigned long stack;
 
-       show_trace(current, &stack);
+       show_trace(current, NULL, &stack);
 }
 
 EXPORT_SYMBOL(dump_stack);
@@ -233,16 +293,18 @@ void show_registers(struct pt_regs *regs)
 
        esp = (unsigned long) (&regs->esp);
        savesegment(ss, ss);
-       if (user_mode(regs)) {
+       if (user_mode_vm(regs)) {
                in_kernel = 0;
                esp = regs->esp;
                ss = regs->xss & 0xffff;
        }
        print_modules();
        printk(KERN_EMERG "CPU:    %d\nEIP:    %04x:[<%08lx>]    %s VLI\n"
-                       "EFLAGS: %08lx   (%s) \n",
+                       "EFLAGS: %08lx   (%s %.*s) \n",
                smp_processor_id(), 0xffff & regs->xcs, regs->eip,
-               print_tainted(), regs->eflags, system_utsname.release);
+               print_tainted(), regs->eflags, system_utsname.release,
+               (int)strcspn(system_utsname.version, " "),
+               system_utsname.version);
        print_symbol(KERN_EMERG "EIP is at %s\n", regs->eip);
        printk(KERN_EMERG "eax: %08lx   ebx: %08lx   ecx: %08lx   edx: %08lx\n",
                regs->eax, regs->ebx, regs->ecx, regs->edx);
@@ -250,8 +312,9 @@ void show_registers(struct pt_regs *regs)
                regs->esi, regs->edi, regs->ebp, esp);
        printk(KERN_EMERG "ds: %04x   es: %04x   ss: %04x\n",
                regs->xds & 0xffff, regs->xes & 0xffff, ss);
-       printk(KERN_EMERG "Process %s (pid: %d, threadinfo=%p task=%p)",
-               current->comm, current->pid, current_thread_info(), current);
+       printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)",
+               TASK_COMM_LEN, current->comm, current->pid,
+               current_thread_info(), current, current->thread_info);
        /*
         * When in-kernel, we also print out the stack and code at the
         * time of the fault..
@@ -260,7 +323,7 @@ void show_registers(struct pt_regs *regs)
                u8 __user *eip;
 
                printk("\n" KERN_EMERG "Stack: ");
-               show_stack_log_lvl(NULL, (unsigned long *)esp, KERN_EMERG);
+               show_stack_log_lvl(NULL, regs, (unsigned long *)esp, KERN_EMERG);
 
                printk(KERN_EMERG "Code: ");
 
@@ -331,6 +394,8 @@ void die(const char * str, struct pt_regs * regs, long err)
        static int die_counter;
        unsigned long flags;
 
+       oops_enter();
+
        if (die.lock_owner != raw_smp_processor_id()) {
                console_verbose();
                spin_lock_irqsave(&die.lock, flags);
@@ -343,6 +408,9 @@ void die(const char * str, struct pt_regs * regs, long err)
 
        if (++die.lock_owner_depth < 3) {
                int nl = 0;
+               unsigned long esp;
+               unsigned short ss;
+
                handle_BUG(regs);
                printk(KERN_EMERG "%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
 #ifdef CONFIG_PREEMPT
@@ -363,8 +431,23 @@ void die(const char * str, struct pt_regs * regs, long err)
 #endif
                if (nl)
                        printk("\n");
-       notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
-               show_registers(regs);
+               if (notify_die(DIE_OOPS, str, regs, err,
+                                       current->thread.trap_no, SIGSEGV) !=
+                               NOTIFY_STOP) {
+                       show_registers(regs);
+                       /* Executive summary in case the oops scrolled away */
+                       esp = (unsigned long) (&regs->esp);
+                       savesegment(ss, ss);
+                       if (user_mode(regs)) {
+                               esp = regs->esp;
+                               ss = regs->xss & 0xffff;
+                       }
+                       printk(KERN_EMERG "EIP: [<%08lx>] ", regs->eip);
+                       print_symbol("%s", regs->eip);
+                       printk(" SS:ESP %04x:%08lx\n", ss, esp);
+               }
+               else
+                       regs = NULL;
        } else
                printk(KERN_EMERG "Recursive die() failure, output suppressed\n");
 
@@ -372,6 +455,9 @@ void die(const char * str, struct pt_regs * regs, long err)
        die.lock_owner = -1;
        spin_unlock_irqrestore(&die.lock, flags);
 
+       if (!regs)
+               return;
+
        if (kexec_should_crash(current))
                crash_kexec(regs);
 
@@ -383,6 +469,7 @@ void die(const char * str, struct pt_regs * regs, long err)
                ssleep(5);
                panic("Fatal exception");
        }
+       oops_exit();
        do_exit(SIGSEGV);
 }
 
@@ -599,7 +686,7 @@ static DEFINE_SPINLOCK(nmi_print_lock);
 
 void die_nmi (struct pt_regs *regs, const char *msg)
 {
-       if (notify_die(DIE_NMIWATCHDOG, msg, regs, 0, 0, SIGINT) ==
+       if (notify_die(DIE_NMIWATCHDOG, msg, regs, 0, 2, SIGINT) ==
            NOTIFY_STOP)
                return;
 
@@ -621,7 +708,7 @@ void die_nmi (struct pt_regs *regs, const char *msg)
        /* If we are in kernel we are probably nested up pretty bad
         * and might aswell get out now while we still can.
        */
-       if (!user_mode(regs)) {
+       if (!user_mode_vm(regs)) {
                current->thread.trap_no = 2;
                crash_kexec(regs);
        }
@@ -638,7 +725,7 @@ static void default_do_nmi(struct pt_regs * regs)
                reason = get_nmi_reason();
  
        if (!(reason & 0xc0)) {
-               if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 0, SIGINT)
+               if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
                                                        == NOTIFY_STOP)
                        return;
 #ifdef CONFIG_X86_LOCAL_APIC
@@ -654,7 +741,7 @@ static void default_do_nmi(struct pt_regs * regs)
                unknown_nmi_error(reason, regs);
                return;
        }
-       if (notify_die(DIE_NMI, "nmi", regs, reason, 0, SIGINT) == NOTIFY_STOP)
+       if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
                return;
        if (reason & 0x80)
                mem_parity_error(reason, regs);
@@ -692,6 +779,7 @@ fastcall void do_nmi(struct pt_regs * regs, long error_code)
 
 void set_nmi_callback(nmi_callback_t callback)
 {
+       vmalloc_sync_all();
        rcu_assign_pointer(nmi_callback, callback);
 }
 EXPORT_SYMBOL_GPL(set_nmi_callback);
@@ -1162,6 +1250,18 @@ void __init trap_init(void)
 static int __init kstack_setup(char *s)
 {
        kstack_depth_to_print = simple_strtoul(s, NULL, 0);
-       return 0;
+       return 1;
 }
 __setup("kstack=", kstack_setup);
+
+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, "new") == 0)
+               call_trace = 1;
+       return 1;
+}
+__setup("call_trace=", call_trace_setup);