Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 193 insertions, 0 deletions

diff --git a/kernel/include/linux/tracehook.h b/kernel/include/linux/tracehook.h
new file mode 100644
index 000000000..84d497297
--- /dev/null
+++ b/kernel/include/linux/tracehook.h
@@ -0,0 +1,193 @@
+/*
+ * Tracing hooks
+ *
+ * Copyright (C) 2008-2009 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2.
+ *
+ * This file defines hook entry points called by core code where
+ * user tracing/debugging support might need to do something.  These
+ * entry points are called tracehook_*().  Each hook declared below
+ * has a detailed kerneldoc comment giving the context (locking et
+ * al) from which it is called, and the meaning of its return value.
+ *
+ * Each function here typically has only one call site, so it is ok
+ * to have some nontrivial tracehook_*() inlines.  In all cases, the
+ * fast path when no tracing is enabled should be very short.
+ *
+ * The purpose of this file and the tracehook_* layer is to consolidate
+ * the interface that the kernel core and arch code uses to enable any
+ * user debugging or tracing facility (such as ptrace).  The interfaces
+ * here are carefully documented so that maintainers of core and arch
+ * code do not need to think about the implementation details of the
+ * tracing facilities.  Likewise, maintainers of the tracing code do not
+ * need to understand all the calling core or arch code in detail, just
+ * documented circumstances of each call, such as locking conditions.
+ *
+ * If the calling core code changes so that locking is different, then
+ * it is ok to change the interface documented here.  The maintainer of
+ * core code changing should notify the maintainers of the tracing code
+ * that they need to work out the change.
+ *
+ * Some tracehook_*() inlines take arguments that the current tracing
+ * implementations might not necessarily use.  These function signatures
+ * are chosen to pass in all the information that is on hand in the
+ * caller and might conceivably be relevant to a tracer, so that the
+ * core code won't have to be updated when tracing adds more features.
+ * If a call site changes so that some of those parameters are no longer
+ * already on hand without extra work, then the tracehook_* interface
+ * can change so there is no make-work burden on the core code.  The
+ * maintainer of core code changing should notify the maintainers of the
+ * tracing code that they need to work out the change.
+ */
+
+#ifndef _LINUX_TRACEHOOK_H
+#define _LINUX_TRACEHOOK_H	1
+
+#include <linux/sched.h>
+#include <linux/ptrace.h>
+#include <linux/security.h>
+#include <linux/task_work.h>
+struct linux_binprm;
+
+/*
+ * ptrace report for syscall entry and exit looks identical.
+ */
+static inline int ptrace_report_syscall(struct pt_regs *regs)
+{
+	int ptrace = current->ptrace;
+
+	if (!(ptrace & PT_PTRACED))
+		return 0;
+
+	ptrace_notify(SIGTRAP | ((ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
+
+	/*
+	 * this isn't the same as continuing with a signal, but it will do
+	 * for normal use.  strace only continues with a signal if the
+	 * stopping signal is not SIGTRAP.  -brl
+	 */
+	if (current->exit_code) {
+		send_sig(current->exit_code, current, 1);
+		current->exit_code = 0;
+	}
+
+	return fatal_signal_pending(current);
+}
+
+/**
+ * tracehook_report_syscall_entry - task is about to attempt a system call
+ * @regs:		user register state of current task
+ *
+ * This will be called if %TIF_SYSCALL_TRACE has been set, when the
+ * current task has just entered the kernel for a system call.
+ * Full user register state is available here.  Changing the values
+ * in @regs can affect the system call number and arguments to be tried.
+ * It is safe to block here, preventing the system call from beginning.
+ *
+ * Returns zero normally, or nonzero if the calling arch code should abort
+ * the system call.  That must prevent normal entry so no system call is
+ * made.  If @task ever returns to user mode after this, its register state
+ * is unspecified, but should be something harmless like an %ENOSYS error
+ * return.  It should preserve enough information so that syscall_rollback()
+ * can work (see asm-generic/syscall.h).
+ *
+ * Called without locks, just after entering kernel mode.
+ */
+static inline __must_check int tracehook_report_syscall_entry(
+	struct pt_regs *regs)
+{
+	return ptrace_report_syscall(regs);
+}
+
+/**
+ * tracehook_report_syscall_exit - task has just finished a system call
+ * @regs:		user register state of current task
+ * @step:		nonzero if simulating single-step or block-step
+ *
+ * This will be called if %TIF_SYSCALL_TRACE has been set, when the
+ * current task has just finished an attempted system call.  Full
+ * user register state is available here.  It is safe to block here,
+ * preventing signals from being processed.
+ *
+ * If @step is nonzero, this report is also in lieu of the normal
+ * trap that would follow the system call instruction because
+ * user_enable_block_step() or user_enable_single_step() was used.
+ * In this case, %TIF_SYSCALL_TRACE might not be set.
+ *
+ * Called without locks, just before checking for pending signals.
+ */
+static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
+{
+	if (step) {
+		siginfo_t info;
+		user_single_step_siginfo(current, regs, &info);
+		force_sig_info(SIGTRAP, &info, current);
+		return;
+	}
+
+	ptrace_report_syscall(regs);
+}
+
+/**
+ * tracehook_signal_handler - signal handler setup is complete
+ * @stepping:		nonzero if debugger single-step or block-step in use
+ *
+ * Called by the arch code after a signal handler has been set up.
+ * Register and stack state reflects the user handler about to run.
+ * Signal mask changes have already been made.
+ *
+ * Called without locks, shortly before returning to user mode
+ * (or handling more signals).
+ */
+static inline void tracehook_signal_handler(int stepping)
+{
+	if (stepping)
+		ptrace_notify(SIGTRAP);
+}
+
+/**
+ * set_notify_resume - cause tracehook_notify_resume() to be called
+ * @task:		task that will call tracehook_notify_resume()
+ *
+ * Calling this arranges that @task will call tracehook_notify_resume()
+ * before returning to user mode.  If it's already running in user mode,
+ * it will enter the kernel and call tracehook_notify_resume() soon.
+ * If it's blocked, it will not be woken.
+ */
+static inline void set_notify_resume(struct task_struct *task)
+{
+#ifdef TIF_NOTIFY_RESUME
+	if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_RESUME))
+		kick_process(task);
+#endif
+}
+
+/**
+ * tracehook_notify_resume - report when about to return to user mode
+ * @regs:		user-mode registers of @current task
+ *
+ * This is called when %TIF_NOTIFY_RESUME has been set.  Now we are
+ * about to return to user mode, and the user state in @regs can be
+ * inspected or adjusted.  The caller in arch code has cleared
+ * %TIF_NOTIFY_RESUME before the call.  If the flag gets set again
+ * asynchronously, this will be called again before we return to
+ * user mode.
+ *
+ * Called without locks.
+ */
+static inline void tracehook_notify_resume(struct pt_regs *regs)
+{
+	/*
+	 * The caller just cleared TIF_NOTIFY_RESUME. This barrier
+	 * pairs with task_work_add()->set_notify_resume() after
+	 * hlist_add_head(task->task_works);
+	 */
+	smp_mb__after_atomic();
+	if (unlikely(current->task_works))
+		task_work_run();
+}
+
+#endif	/* <linux/tracehook.h> */