diff -urpN --exclude-from=/home/davej/.exclude bk-linus/arch/i386/kernel/traps.c linux-2.5/arch/i386/kernel/traps.c
--- bk-linus/arch/i386/kernel/traps.c	2002-11-21 02:09:31.000000000 +0000
+++ linux-2.5/arch/i386/kernel/traps.c	2002-11-21 17:55:03.000000000 +0000
@@ -577,10 +581,15 @@ asmlinkage void do_debug(struct pt_regs 
 {
 	unsigned int condition;
 	struct task_struct *tsk = current;
+	unsigned long eip = regs->eip;
 	siginfo_t info;
 
 	__asm__ __volatile__("movl %%db6,%0" : "=r" (condition));
 
+	/* If the user set TF, it's simplest to clear it right away. */
+	if ((eip >=PAGE_OFFSET) && (regs->eflags & TF_MASK))
+		goto clear_TF;
+
 	/* Mask out spurious debug traps due to lazy DR7 setting */
 	if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
 		if (!tsk->thread.debugreg[7])