avr32, mn10300, parisc, s390, sh, xtensa:

they never set PT_DTRACE, but clear it after do_execve().

--- PTRACE/arch/avr32/kernel/process.c~DT_2_CLEAR	2009-04-06 00:03:35.000000000 +0200
+++ PTRACE/arch/avr32/kernel/process.c	2009-04-22 21:35:25.000000000 +0200
@@ -394,8 +394,6 @@ asmlinkage int sys_execve(char __user *u
 		goto out;
 
 	error = do_execve(filename, uargv, uenvp, regs);
-	if (error == 0)
-		current->ptrace &= ~PT_DTRACE;
 	putname(filename);
 
 out:
--- PTRACE/arch/mn10300/kernel/process.c~DT_2_CLEAR	2009-04-06 00:03:35.000000000 +0200
+++ PTRACE/arch/mn10300/kernel/process.c	2009-04-22 21:38:00.000000000 +0200
@@ -281,9 +281,6 @@ asmlinkage long sys_execve(char __user *
 	error = PTR_ERR(filename);
 	if (!IS_ERR(filename)) {
 		error = do_execve(filename, argv, envp, __frame);
-		if (error == 0)
-			current->ptrace &= ~PT_DTRACE;
-
 		putname(filename);
 	}
 
--- PTRACE/arch/parisc/hpux/fs.c~DT_2_CLEAR	2009-04-06 00:03:35.000000000 +0200
+++ PTRACE/arch/parisc/hpux/fs.c	2009-04-22 21:39:00.000000000 +0200
@@ -44,11 +44,6 @@ int hpux_execve(struct pt_regs *regs)
 	error = do_execve(filename, (char __user * __user *) regs->gr[25],
 		(char __user * __user *) regs->gr[24], regs);
 
-	if (error == 0) {
-		task_lock(current);
-		current->ptrace &= ~PT_DTRACE;
-		task_unlock(current);
-	}
 	putname(filename);
 
 out:
--- PTRACE/arch/parisc/kernel/process.c~DT_2_CLEAR	2009-04-06 00:03:35.000000000 +0200
+++ PTRACE/arch/parisc/kernel/process.c	2009-04-22 21:41:57.000000000 +0200
@@ -349,11 +349,6 @@ asmlinkage int sys_execve(struct pt_regs
 		goto out;
 	error = do_execve(filename, (char __user * __user *) regs->gr[25],
 		(char __user * __user *) regs->gr[24], regs);
-	if (error == 0) {
-		task_lock(current);
-		current->ptrace &= ~PT_DTRACE;
-		task_unlock(current);
-	}
 	putname(filename);
 out:
 
--- PTRACE/arch/parisc/kernel/sys_parisc32.c~DT_2_CLEAR	2009-04-06 00:03:35.000000000 +0200
+++ PTRACE/arch/parisc/kernel/sys_parisc32.c	2009-04-22 21:42:19.000000000 +0200
@@ -77,11 +77,6 @@ asmlinkage int sys32_execve(struct pt_re
 		goto out;
 	error = compat_do_execve(filename, compat_ptr(regs->gr[25]),
 				 compat_ptr(regs->gr[24]), regs);
-	if (error == 0) {
-		task_lock(current);
-		current->ptrace &= ~PT_DTRACE;
-		task_unlock(current);
-	}
 	putname(filename);
 out:
 
--- PTRACE/arch/s390/kernel/compat_linux.c~DT_2_CLEAR	2009-04-22 20:49:07.000000000 +0200
+++ PTRACE/arch/s390/kernel/compat_linux.c	2009-04-22 21:45:01.000000000 +0200
@@ -461,9 +461,6 @@ asmlinkage long sys32_execve(void)
 		result = rc;
 		goto out_putname;
 	}
-	task_lock(current);
-	current->ptrace &= ~PT_DTRACE;
-	task_unlock(current);
 	current->thread.fp_regs.fpc=0;
 	asm volatile("sfpc %0,0" : : "d" (0));
 	result = regs->gprs[2];
--- PTRACE/arch/s390/kernel/process.c~DT_2_CLEAR	2009-04-06 00:03:36.000000000 +0200
+++ PTRACE/arch/s390/kernel/process.c	2009-04-22 21:45:27.000000000 +0200
@@ -265,9 +265,6 @@ SYSCALL_DEFINE0(vfork)
 
 asmlinkage void execve_tail(void)
 {
-	task_lock(current);
-	current->ptrace &= ~PT_DTRACE;
-	task_unlock(current);
 	current->thread.fp_regs.fpc = 0;
 	if (MACHINE_HAS_IEEE)
 		asm volatile("sfpc %0,%0" : : "d" (0));
--- PTRACE/arch/sh/kernel/process_32.c~DT_2_CLEAR	2009-04-06 00:03:36.000000000 +0200
+++ PTRACE/arch/sh/kernel/process_32.c	2009-04-22 21:46:30.000000000 +0200
@@ -366,11 +366,6 @@ asmlinkage int sys_execve(char __user *u
 		goto out;
 
 	error = do_execve(filename, uargv, uenvp, regs);
-	if (error == 0) {
-		task_lock(current);
-		current->ptrace &= ~PT_DTRACE;
-		task_unlock(current);
-	}
 	putname(filename);
 out:
 	return error;
--- PTRACE/arch/sh/kernel/process_64.c~DT_2_CLEAR	2009-04-06 00:03:36.000000000 +0200
+++ PTRACE/arch/sh/kernel/process_64.c	2009-04-22 21:46:52.000000000 +0200
@@ -529,11 +529,6 @@ asmlinkage int sys_execve(char *ufilenam
 			  (char __user * __user *)uargv,
 			  (char __user * __user *)uenvp,
 			  pregs);
-	if (error == 0) {
-		task_lock(current);
-		current->ptrace &= ~PT_DTRACE;
-		task_unlock(current);
-	}
 	putname(filename);
 out:
 	return error;
--- PTRACE/arch/xtensa/kernel/process.c~DT_2_CLEAR	2009-04-06 00:03:37.000000000 +0200
+++ PTRACE/arch/xtensa/kernel/process.c	2009-04-22 21:48:13.000000000 +0200
@@ -331,11 +331,6 @@ long xtensa_execve(char __user *name, ch
 	if (IS_ERR(filename))
 		goto out;
 	error = do_execve(filename, argv, envp, regs);
-	if (error == 0) {
-		task_lock(current);
-		current->ptrace &= ~PT_DTRACE;
-		task_unlock(current);
-	}
 	putname(filename);
 out:
 	return error;