Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 204 insertions, 0 deletions

diff --git a/Documentation/fb/sstfb.rst b/Documentation/fb/sstfb.rst
new file mode 100644
index 000000000..7386eb63b
--- /dev/null
+++ b/Documentation/fb/sstfb.rst
@@ -0,0 +1,204 @@
+=====
+sstfb
+=====
+
+Introduction
+============
+
+This is a frame buffer device driver for 3dfx' Voodoo Graphics
+(aka voodoo 1, aka sst1) and Voodoo² (aka Voodoo 2, aka CVG) based
+video boards. It's highly experimental code, but is guaranteed to work
+on my computer, with my "Maxi Gamer 3D" and "Maxi Gamer 3d²" boards,
+and with me "between chair and keyboard". Some people tested other
+combinations and it seems that it works.
+The main page is located at <http://sstfb.sourceforge.net>, and if
+you want the latest version, check out the CVS, as the driver is a work
+in progress, I feel uncomfortable with releasing tarballs of something
+not completely working...Don't worry, it's still more than usable
+(I eat my own dog food)
+
+Please read the Bug section, and report any success or failure to me
+(Ghozlane Toumi <gtoumi@laposte.net>).
+BTW, If you have only one monitor , and you don't feel like playing
+with the vga passthrou cable, I can only suggest borrowing a screen
+somewhere...
+
+
+Installation
+============
+
+This driver (should) work on ix86, with "late" 2.2.x kernel (tested
+with x = 19) and "recent" 2.4.x kernel, as a module or compiled in.
+It has been included in mainstream kernel since the infamous 2.4.10.
+You can apply the patches found in `sstfb/kernel/*-2.{2|4}.x.patch`,
+and copy sstfb.c to linux/drivers/video/, or apply a single patch,
+`sstfb/patch-2.{2|4}.x-sstfb-yymmdd` to your linux source tree.
+
+Then configure your kernel as usual: choose "m" or "y" to 3Dfx Voodoo
+Graphics in section "console". Compile, install, have fun... and please
+drop me a report :)
+
+
+Module Usage
+============
+
+.. warning::
+
+       #. You should read completely this section before issuing any command.
+
+       #. If you have only one monitor to play with, once you insmod the
+	  module, the 3dfx takes control of the output, so you'll have to
+	  plug the monitor to the "normal" video board in order to issue
+	  the commands, or you can blindly use sst_dbg_vgapass
+	  in the tools directory (See Tools). The latest solution is pass the
+	  parameter vgapass=1 when insmodding the driver. (See Kernel/Modules
+	  Options)
+
+Module insertion
+----------------
+
+       #. insmod sstfb.o
+
+	  you should see some strange output from the board:
+	  a big blue square, a green and a red small squares and a vertical
+	  white rectangle. why? the function's name is self-explanatory:
+	  "sstfb_test()"...
+	  (if you don't have a second monitor, you'll have to plug your monitor
+	  directly to the 2D videocard to see what you're typing)
+
+       #. con2fb /dev/fbx /dev/ttyx
+
+	  bind a tty to the new frame buffer. if you already have a frame
+	  buffer driver, the voodoo fb will likely be /dev/fb1. if not,
+	  the device will be /dev/fb0. You can check this by doing a
+	  cat /proc/fb. You can find a copy of con2fb in tools/ directory.
+	  if you don't have another fb device, this step is superfluous,
+	  as the console subsystem automagically binds ttys to the fb.
+       #. switch to the virtual console you just mapped. "tadaaa" ...
+
+Module removal
+--------------
+
+       #. con2fb /dev/fbx /dev/ttyx
+
+	  bind the tty to the old frame buffer so the module can be removed.
+	  (how does it work with vgacon ? short answer : it doesn't work)
+
+       #. rmmod sstfb
+
+
+Kernel/Modules Options
+----------------------
+
+You can pass some options to the sstfb module, and via the kernel
+command line when the driver is compiled in:
+for module : insmod sstfb.o option1=value1 option2=value2 ...
+in kernel :  video=sstfb:option1,option2:value2,option3 ...
+
+sstfb supports the following options:
+
+=============== =============== ===============================================
+Module		Kernel		Description
+=============== =============== ===============================================
+vgapass=0	vganopass	Enable or disable VGA passthrou cable.
+vgapass=1	vgapass		When enabled, the monitor will get the signal
+				from the VGA board and not from the voodoo.
+
+				Default: nopass
+
+mem=x		mem:x		Force frame buffer memory in MiB
+				allowed values: 0, 1, 2, 4.
+
+				Default: 0 (= autodetect)
+
+inverse=1	inverse		Supposed to enable inverse console.
+				doesn't work yet...
+
+clipping=1	clipping	Enable or disable clipping.
+clipping=0	noclipping	With clipping enabled, all offscreen
+				reads and writes are discarded.
+
+				Default: enable clipping.
+
+gfxclk=x	gfxclk:x	Force graphic clock frequency (in MHz).
+				Be careful with this option, it may be
+				DANGEROUS.
+
+				Default: auto
+
+					- 50Mhz for Voodoo 1,
+					- 75MHz for Voodoo 2.
+
+slowpci=1	fastpci		Enable or disable fast PCI read/writes.
+slowpci=1	slowpci		Default : fastpci
+
+dev=x		dev:x		Attach the driver to device number x.
+				0 is the first compatible board (in
+				lspci order)
+=============== =============== ===============================================
+
+Tools
+=====
+
+These tools are mostly for debugging purposes, but you can
+find some of these interesting:
+
+- `con2fb`, maps a tty to a fbramebuffer::
+
+	con2fb /dev/fb1 /dev/tty5
+
+- `sst_dbg_vgapass`, changes vga passthrou. You have to recompile the
+  driver with SST_DEBUG and SST_DEBUG_IOCTL set to 1::
+
+	sst_dbg_vgapass /dev/fb1 1 (enables vga cable)
+	sst_dbg_vgapass /dev/fb1 0 (disables vga cable)
+
+- `glide_reset`, resets the voodoo using glide
+  use this after rmmoding sstfb, if the module refuses to
+  reinsert.
+
+Bugs
+====
+
+- DO NOT use glide while the sstfb module is in, you'll most likely
+  hang your computer.
+- If you see some artefacts (pixels not cleaning and stuff like that),
+  try turning off clipping (clipping=0), and/or using slowpci
+- the driver don't detect the 4Mb frame buffer voodoos, it seems that
+  the 2 last Mbs wrap around. looking into that .
+- The driver is 16 bpp only, 24/32 won't work.
+- The driver is not your_favorite_toy-safe. this includes SMP...
+
+	[Actually from inspection it seems to be safe - Alan]
+
+- When using XFree86 FBdev (X over fbdev) you may see strange color
+  patterns at the border of your windows (the pixels lose the lowest
+  byte -> basically the blue component and some of the green). I'm unable
+  to reproduce this with XFree86-3.3, but one of the testers has this
+  problem with XFree86-4. Apparently recent Xfree86-4.x solve this
+  problem.
+- I didn't really test changing the palette, so you may find some weird
+  things when playing with that.
+- Sometimes the driver will not recognise the DAC, and the
+  initialisation will fail. This is specifically true for
+  voodoo 2 boards, but it should be solved in recent versions. Please
+  contact me.
+- The 24/32 is not likely to work anytime soon, knowing that the
+  hardware does ... unusual things in 24/32 bpp.
+
+Todo
+====
+
+- Get rid of the previous paragraph.
+- Buy more coffee.
+- test/port to other arch.
+- try to add panning using tweaks with front and back buffer.
+- try to implement accel on voodoo2, this board can actually do a
+  lot in 2D even if it was sold as a 3D only board ...
+
+Ghozlane Toumi <gtoumi@laposte.net>
+
+
+Date: 2002/05/09 20:11:45
+
+http://sstfb.sourceforge.net/README