fix single step handling for 32bit processes

From: Peter Beutner <p.beutner@gmx.net>

Be more careful with TF handling to fix some copy protection codes in wine

patch originally for i386 by Linus, then ported to x86_64 by Andi Kleen
see: [PATCH] x86_64: Some fixes for single step handling
commit: be61bff789fe44bfb6d9282d8f7eccc860bdcfb6

But it was never applied to the ia32 emulation code which breaks some
copy-protection schemes under wine when running on x86_64.

Signed-off-by: Peter Beutner <p.beutner@gmx.net>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Index: linux/arch/x86_64/ia32/ia32_signal.c
===================================================================
--- linux.orig/arch/x86_64/ia32/ia32_signal.c
+++ linux/arch/x86_64/ia32/ia32_signal.c
@@ -353,7 +353,6 @@ ia32_setup_sigcontext(struct sigcontext_
 		 struct pt_regs *regs, unsigned int mask)
 {
 	int tmp, err = 0;
-	u32 eflags;
 
 	tmp = 0;
 	__asm__("movl %%gs,%0" : "=r"(tmp): "0"(tmp));
@@ -378,10 +377,7 @@ ia32_setup_sigcontext(struct sigcontext_
 	err |= __put_user(current->thread.trap_no, &sc->trapno);
 	err |= __put_user(current->thread.error_code, &sc->err);
 	err |= __put_user((u32)regs->rip, &sc->eip);
-	eflags = regs->eflags;
-	if (current->ptrace & PT_PTRACED)
-		eflags &= ~TF_MASK;
-	err |= __put_user((u32)eflags, &sc->eflags);
+	err |= __put_user((u32)regs->eflags, &sc->eflags);
 	err |= __put_user((u32)regs->rsp, &sc->esp_at_signal);
 
 	tmp = save_i387_ia32(current, fpstate, regs, 0);
@@ -505,13 +501,9 @@ int ia32_setup_frame(int sig, struct k_s
 	regs->ss = __USER32_DS; 
 
 	set_fs(USER_DS);
-	if (regs->eflags & TF_MASK) {
-		if (current->ptrace & PT_PTRACED) {
-			ptrace_notify(SIGTRAP);
-		} else {
-			regs->eflags &= ~TF_MASK;
-		}
-	}
+    regs->eflags &= ~TF_MASK;
+    if (test_thread_flag(TIF_SINGLESTEP))
+        ptrace_notify(SIGTRAP);
 
 #if DEBUG_SIG
 	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
@@ -605,13 +597,9 @@ int ia32_setup_rt_frame(int sig, struct 
 	regs->ss = __USER32_DS; 
 
 	set_fs(USER_DS);
-	if (regs->eflags & TF_MASK) {
-		if (current->ptrace & PT_PTRACED) {
-			ptrace_notify(SIGTRAP);
-		} else {
-			regs->eflags &= ~TF_MASK;
-		}
-	}
+    regs->eflags &= ~TF_MASK;
+    if (test_thread_flag(TIF_SINGLESTEP))
+        ptrace_notify(SIGTRAP);
 
 #if DEBUG_SIG
 	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",