x86 single_step: TIF_FORCED_TF

[pandora-kernel.git] / arch / x86 / kernel / traps_64.c

diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
index df690c3..874aca3 100644 (file)
--- a/arch/x86/kernel/traps_64.c
+++ b/arch/x86/kernel/traps_64.c
@@ -31,6 +31,7 @@
 #include <linux/uaccess.h>
 #include <linux/bug.h>
 #include <linux/kdebug.h>
+#include <linux/utsname.h>
 
 #if defined(CONFIG_EDAC)
 #include <linux/edac.h>
@@ -201,7 +202,7 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
 #define MSG(txt) ops->warning(data, txt)
 
 /*
- * x86-64 can have upto three kernel stacks: 
+ * x86-64 can have up to three kernel stacks: 
  * process stack
  * interrupt stack
  * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
@@ -400,6 +401,12 @@ void show_stack(struct task_struct *tsk, unsigned long * rsp)
 void dump_stack(void)
 {
        unsigned long dummy;
+
+       printk("Pid: %d, comm: %.20s %s %s %.*s\n",
+               current->pid, current->comm, print_tainted(),
+               init_utsname()->release,
+               (int)strcspn(init_utsname()->version, " "),
+               init_utsname()->version);
        show_trace(NULL, NULL, &dummy);
 }
 
@@ -454,14 +461,6 @@ int is_valid_bugaddr(unsigned long rip)
        return ud2 == 0x0b0f;
 }
 
-#ifdef CONFIG_BUG
-void out_of_line_bug(void)
-{ 
-       BUG(); 
-} 
-EXPORT_SYMBOL(out_of_line_bug);
-#endif
-
 static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
 static int die_owner = -1;
 static unsigned int die_nest_count;
@@ -628,6 +627,7 @@ asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
        info.si_errno = 0; \
        info.si_code = sicode; \
        info.si_addr = (void __user *)siaddr; \
+       trace_hardirqs_fixup(); \
        if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
                                                        == NOTIFY_STOP) \
                return; \
@@ -807,6 +807,8 @@ asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
 /* runs on IST stack. */
 asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
 {
+       trace_hardirqs_fixup();
+
        if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
                return;
        }
@@ -844,6 +846,8 @@ asmlinkage void __kprobes do_debug(struct pt_regs * regs,
        struct task_struct *tsk = current;
        siginfo_t info;
 
+       trace_hardirqs_fixup();
+
        get_debugreg(condition, 6);
 
        if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
@@ -861,27 +865,14 @@ asmlinkage void __kprobes do_debug(struct pt_regs * regs,
 
        tsk->thread.debugreg6 = condition;
 
-       /* Mask out spurious TF errors due to lazy TF clearing */
+
+       /*
+        * Single-stepping through TF: make sure we ignore any events in
+        * kernel space (but re-enable TF when returning to user mode).
+        */
        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
-                * previously by a tracing process (condition detected by
-                * the PT_DTRACE flag); remember that the i386 TRAP flag
-                * can be modified by the process itself in user mode,
-                * allowing programs to debug themselves without the ptrace()
-                * interface.
-                */
                 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 */