Avoid overflow possibility.

[ The overflow is purely theoretical, since this is used for memory
  ranges that aren't even close to using the full 64 bits, but this is
  the right thing to do regardless.  - Linus ]

Signed-off-by: Louis Langholtz <lou_langholtz@me.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Peter Anvin <hpa@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ftrace fixes from Steven Rostedt:
 "This holds a few fixes to the ftrace infrastructure as well as the
  mixture of function graph tracing and kprobes.

  When jprobes and function graph tracing is enabled at the same time it
  will crash the system:

      # modprobe jprobe_example
      # echo function_graph > /sys/kernel/debug/tracing/current_tracer

  After the first fork (jprobe_example probes it), the system will
  crash.

  This is due to the way jprobes copies the stack frame and does not do
  a normal function return.  This messes up with the function graph
  tracing accounting which hijacks the return address from the stack and
  replaces it with a hook function.  It saves the return addresses in a
  separate stack to put back the correct return address when done.  But
  because the jprobe functions do not do a normal return, their stack
  addresses are not put back until the function they probe is called,
  which means that the probed function will get the return address of
  the jprobe handler instead of its own.

  The simple fix here was to disable function graph tracing while the
  jprobe handler is being called.

  While debugging this I found two minor bugs with the function graph
  tracing.

  The first was about the function graph tracer sharing its function
  hash with the function tracer (they both get filtered by the same
  input).  The changing of the set_ftrace_filter would not sync the
  function recording records after a change if the function tracer was
  disabled but the function graph tracer was enabled.  This was due to
  the update only checking one of the ops instead of the shared ops to
  see if they were enabled and should perform the sync.  This caused the
  ftrace accounting to break and a ftrace_bug() would be triggered,
  disabling ftrace until a reboot.

  The second was that the check to update records only checked one of
  the filter hashes.  It needs to test both the "filter" and "notrace"
  hashes.  The "filter" hash determines what functions to trace where as
  the "notrace" hash determines what functions not to trace (trace all
  but these).  Both hashes need to be passed to the update code to find
  out what change is being done during the update.  This also broke the
  ftrace record accounting and triggered a ftrace_bug().

  This patch set also include two more fixes that were reported
  separately from the kprobe issue.

  One was that init_ftrace_syscalls() was called twice at boot up.  This
  is not a major bug, but that call performed a rather large kmalloc
  (NR_syscalls * sizeof(*syscalls_metadata)).  The second call made the
  first one a memory leak, and wastes memory.

  The other fix is a regression caused by an update in the v3.19 merge
  window.  The moving to enable events early, moved the enabling before
  PID 1 was created.  The syscall events require setting the
  TIF_SYSCALL_TRACEPOINT for all tasks.  But for_each_process_thread()
  does not include the swapper task (PID 0), and ended up being a nop.

  A suggested fix was to add the init_task() to have its flag set, but I
  didn't really want to mess with PID 0 for this minor bug.  Instead I
  disable and re-enable events again at early_initcall() where it use to
  be enabled.  This also handles any other event that might have its own
  reg function that could break at early boot up"

* tag 'trace-fixes-v3.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix enabling of syscall events on the command line
  tracing: Remove extra call to init_ftrace_syscalls()
  ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing
  ftrace: Check both notrace and filter for old hash
  ftrace: Fix updating of filters for shared global_ops filters

Commit 5f893b2639b2 "tracing: Move enabling tracepoints to just after
rcu_init()" broke the enabling of system call events from the command
line. The reason was that the enabling of command line trace events
was moved before PID 1 started, and the syscall tracepoints require
that all tasks have the TIF_SYSCALL_TRACEPOINT flag set. But the
swapper task (pid 0) is not part of that. Since the swapper task is the
only task that is running at this early in boot, no task gets the
flag set, and the tracepoint never gets reached.

Instead of setting the swapper task flag (there should be no reason to
do that), re-enabled trace events again after the init thread (PID 1)
has been started. It requires disabling all command line events and
re-enabling them, as just enabling them again will not reset the logic
to set the TIF_SYSCALL_TRACEPOINT flag, as the syscall tracepoint will
be fooled into thinking that it was already set, and wont try setting
it again. For this reason, we must first disable it and re-enable it.

Link: http://lkml.kernel.org/r/1421188517-18312-1-git-send-email-mpe@ellerman.id.au
Link: http://lkml.kernel.org/r/20150115040506.216066449@goodmis.org

Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

trace_init() calls init_ftrace_syscalls() and then calls trace_event_init()
which also calls init_ftrace_syscalls(). It makes more sense to only
call it from trace_event_init().

Calling it twice wastes memory, as it allocates the syscall events twice,
and loses the first copy of it.

Link: http://lkml.kernel.org/r/54AF53BD.5070303@huawei.com
Link: http://lkml.kernel.org/r/20150115040505.930398632@goodmis.org

Reported-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Using just the filter for checking for trampolines or regs is not enough
when updating the code against the records that represent all functions.
Both the filter hash and the notrace hash need to be checked.

To trigger this bug (using trace-cmd and perf):

 # perf probe -a do_fork
 # trace-cmd start -B foo -e probe
 # trace-cmd record -p function_graph -n do_fork sleep 1

The trace-cmd record at the end clears the filter before it disables
function_graph tracing and then that causes the accounting of the
ftrace function records to become incorrect and causes ftrace to bug.

Link: http://lkml.kernel.org/r/20150114154329.358378039@goodmis.org

Cc: stable@vger.kernel.org
[ still need to switch old_hash_ops to old_ops_hash ]
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

As the set_ftrace_filter affects both the function tracer as well as the
function graph tracer, the ops that represent each have a shared
ftrace_ops_hash structure. This allows both to be updated when the filter
files are updated.

But if function graph is enabled and the global_ops (function tracing) ops
is not, then it is possible that the filter could be changed without the
update happening for the function graph ops. This will cause the changes
to not take place and may even cause a ftrace_bug to occur as it could mess
with the trampoline accounting.

The solution is to check if the ops uses the shared global_ops filter and
if the ops itself is not enabled, to check if there's another ops that is
enabled and also shares the global_ops filter. In that case, the
modification still needs to be executed.

Link: http://lkml.kernel.org/r/20150114154329.055980438@goodmis.org

Cc: stable@vger.kernel.org # 3.17+
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Pull scheduler fixes from Ingo Molnar:
 "Misc fixes: group scheduling corner case fix, two deadline scheduler
  fixes, effective_load() overflow fix, nested sleep fix, 6144 CPUs
  system fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix RCU stall upon -ENOMEM in sched_create_group()
  sched/deadline: Avoid double-accounting in case of missed deadlines
  sched/deadline: Fix migration of SCHED_DEADLINE tasks
  sched: Fix odd values in effective_load() calculations
  sched, fanotify: Deal with nested sleeps
  sched: Fix KMALLOC_MAX_SIZE overflow during cpumask allocation

Pull perf fixes from Ingo Molnar:
 "Mostly tooling fixes, but also some kernel side fixes: uncore PMU
  driver fix, user regs sampling fix and an instruction decoder fix that
  unbreaks PEBS precise sampling"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/uncore/hsw-ep: Handle systems with only two SBOXes
  perf/x86_64: Improve user regs sampling
  perf: Move task_pt_regs sampling into arch code
  x86: Fix off-by-one in instruction decoder
  perf hists browser: Fix segfault when showing callchain
  perf callchain: Free callchains when hist entries are deleted
  perf hists: Fix children sort key behavior
  perf diff: Fix to sort by baseline field by default
  perf list: Fix --raw-dump option
  perf probe: Fix crash in dwarf_getcfi_elf
  perf probe: Fix to fall back to find probe point in symbols
  perf callchain: Append callchains only when requested
  perf ui/tui: Print backtrace symbols when segfault occurs
  perf report: Show progress bar for output resorting

Pull locking fixes from Ingo Molnar:
 "A liblockdep fix and a mutex_unlock() mutex-debugging fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  mutex: Always clear owner field upon mutex_unlock()
  tools/liblockdep: Fix debug_check thinko in mutex destroy

Pull kgdb/kdb fixes from Jason Wessel:
 "These have been around since 3.17 and in kgdb-next for the last 9
  weeks and some will go back to -stable.

  Summary of changes:

  Cleanups
   - kdb: Remove unused command flags, repeat flags and KDB_REPEAT_NONE

  Fixes
   - kgdb/kdb: Allow access on a single core, if a CPU round up is
     deemed impossible, which will allow inspection of the now "trashed"
     kernel
   - kdb: Add enable mask for the command groups
   - kdb: access controls to restrict sensitive commands"

* tag 'for_linus-3.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
  kernel/debug/debug_core.c: Logging clean-up
  kgdb: timeout if secondary CPUs ignore the roundup
  kdb: Allow access to sensitive commands to be restricted by default
  kdb: Add enable mask for groups of commands
  kdb: Categorize kdb commands (similar to SysRq categorization)
  kdb: Remove KDB_REPEAT_NONE flag
  kdb: Use KDB_REPEAT_* values as flags
  kdb: Rename kdb_register_repeat() to kdb_register_flags()
  kdb: Rename kdb_repeat_t to kdb_cmdflags_t, cmd_repeat to cmd_flags
  kdb: Remove currently unused kdbtab_t->cmd_flags