Merge branch 'upstream-fixes' into upstream
[pandora-kernel.git] / arch / i386 / kernel / traps.c
index 0e49836..0d4005d 100644 (file)
@@ -11,7 +11,6 @@
  * 'Traps.c' handles hardware traps and faults after we have saved some
  * state in 'asm.s'.
  */
-#include <linux/config.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
@@ -28,6 +27,7 @@
 #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 +47,7 @@
 #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>
@@ -92,6 +92,7 @@ asmlinkage void spurious_interrupt_bug(void);
 asmlinkage void machine_check(void);
 
 static int kstack_depth_to_print = 24;
+static int call_trace = 1;
 ATOMIC_NOTIFIER_HEAD(i386die_chain);
 
 int register_die_notifier(struct notifier_block *nb)
@@ -99,13 +100,13 @@ int register_die_notifier(struct notifier_block *nb)
        vmalloc_sync_all();
        return atomic_notifier_chain_register(&i386die_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(&i386die_chain, nb);
 }
-EXPORT_SYMBOL(unregister_die_notifier);
+EXPORT_SYMBOL(unregister_die_notifier); /* used modular by kdb */
 
 static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
 {
@@ -114,28 +115,13 @@ static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
 }
 
 /*
- * Print CONFIG_STACK_BACKTRACE_COLS address/symbol entries per line.
+ * Print one address/symbol entries per line.
  */
-static inline int print_addr_and_symbol(unsigned long addr, char *log_lvl,
-                                       int printed)
+static inline void print_addr_and_symbol(unsigned long addr, char *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);
-
-       printed = (printed + 1) % CONFIG_STACK_BACKTRACE_COLS;
-       if (printed)
-               printk(" ");
-       else
-               printk("\n");
 
-       return printed;
+       print_symbol("%s\n", addr);
 }
 
 static inline unsigned long print_context_stack(struct thread_info *tinfo,
@@ -143,28 +129,44 @@ 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);
-               printed = print_addr_and_symbol(addr, log_lvl, printed);
+               print_addr_and_symbol(addr, log_lvl);
+               /*
+                * 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))
-                       printed = print_addr_and_symbol(addr, log_lvl, printed);
+                       print_addr_and_symbol(addr, log_lvl);
        }
 #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;
+
+       while (unwind(info) == 0 && UNW_PC(info)) {
+               n++;
+               print_addr_and_symbol(UNW_PC(info), log_lvl);
+               if (arch_unw_user_mode(info))
+                       break;
+       }
+       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;
@@ -172,6 +174,37 @@ 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 && !arch_unw_user_mode(&info)) {
+#ifdef CONFIG_STACK_UNWIND
+                       print_symbol("DWARF2 unwinder stuck at %s\n",
+                                    UNW_PC(&info));
+                       if (call_trace == 1) {
+                               printk("Leftover inexact backtrace:\n");
+                               if (UNW_SP(&info))
+                                       stack = (void *)UNW_SP(&info);
+                       } else if (call_trace > 1)
+                               return;
+                       else
+                               printk("Full inexact backtrace again:\n");
+#else
+                       printk("Inexact backtrace:\n");
+#endif
+               }
+       }
+
        if (task == current) {
                /* Grab ebp right from our regs */
                asm ("movl %%ebp, %0" : "=r" (ebp) : );
@@ -192,13 +225,13 @@ static void show_trace_log_lvl(struct task_struct *task,
        }
 }
 
-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;
@@ -219,13 +252,13 @@ static void show_stack_log_lvl(struct task_struct *task, unsigned long *esp,
                printk("%08lx ", *stack++);
        }
        printk("\n%sCall Trace:\n", log_lvl);
-       show_trace_log_lvl(task, esp, log_lvl);
+       show_trace_log_lvl(task, regs, esp, log_lvl);
 }
 
 void show_stack(struct task_struct *task, unsigned long *esp)
 {
        printk("       ");
-       show_stack_log_lvl(task, esp, "");
+       show_stack_log_lvl(task, NULL, esp, "");
 }
 
 /*
@@ -235,7 +268,7 @@ void dump_stack(void)
 {
        unsigned long stack;
 
-       show_trace(current, &stack);
+       show_trace(current, NULL, &stack);
 }
 
 EXPORT_SYMBOL(dump_stack);
@@ -268,8 +301,9 @@ 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..
@@ -278,7 +312,7 @@ 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: ");
 
@@ -301,35 +335,35 @@ void show_registers(struct pt_regs *regs)
 
 static void handle_BUG(struct pt_regs *regs)
 {
+       unsigned long eip = regs->eip;
        unsigned short ud2;
-       unsigned short line;
-       char *file;
-       char c;
-       unsigned long eip;
-
-       eip = regs->eip;
 
        if (eip < PAGE_OFFSET)
-               goto no_bug;
+               return;
        if (__get_user(ud2, (unsigned short __user *)eip))
-               goto no_bug;
+               return;
        if (ud2 != 0x0b0f)
-               goto no_bug;
-       if (__get_user(line, (unsigned short __user *)(eip + 2)))
-               goto bug;
-       if (__get_user(file, (char * __user *)(eip + 4)) ||
-               (unsigned long)file < PAGE_OFFSET || __get_user(c, file))
-               file = "<bad filename>";
+               return;
 
        printk(KERN_EMERG "------------[ cut here ]------------\n");
-       printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line);
 
-no_bug:
-       return;
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+       do {
+               unsigned short line;
+               char *file;
+               char c;
+
+               if (__get_user(line, (unsigned short __user *)(eip + 2)))
+                       break;
+               if (__get_user(file, (char * __user *)(eip + 4)) ||
+                   (unsigned long)file < PAGE_OFFSET || __get_user(c, file))
+                       file = "<bad filename>";
 
-       /* Here we know it was a BUG but file-n-line is unavailable */
-bug:
-       printk(KERN_EMERG "Kernel BUG\n");
+               printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line);
+               return;
+       } while (0);
+#endif
+       printk(KERN_EMERG "Kernel BUG at [verbose debug info unavailable]\n");
 }
 
 /* This is gone through when something in the kernel
@@ -419,11 +453,9 @@ void die(const char * str, struct pt_regs * regs, long err)
        if (in_interrupt())
                panic("Fatal exception in interrupt");
 
-       if (panic_on_oops) {
-               printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
-               ssleep(5);
-               panic("Fatal exception");
-       }
+       if (panic_on_oops)
+               panic("Fatal exception: panic_on_oops");
+
        oops_exit();
        do_exit(SIGSEGV);
 }
@@ -1208,3 +1240,17 @@ static int __init kstack_setup(char *s)
        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, "newfallback") == 0)
+               call_trace = 1;
+       else if (strcmp(s, "new") == 2)
+               call_trace = 2;
+       return 1;
+}
+__setup("call_trace=", call_trace_setup);