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, 287 insertions, 0 deletions

diff --git a/Documentation/fb/intel810.rst b/Documentation/fb/intel810.rst
new file mode 100644
index 000000000..eb86098db
--- /dev/null
+++ b/Documentation/fb/intel810.rst
@@ -0,0 +1,287 @@
+================================
+Intel 810/815 Framebuffer driver
+================================
+
+Tony Daplas <adaplas@pol.net>
+
+http://i810fb.sourceforge.net
+
+March 17, 2002
+
+First Released: July 2001
+Last Update:    September 12, 2005
+
+A. Introduction
+===============
+
+	This is a framebuffer driver for various Intel 810/815 compatible
+	graphics devices.  These include:
+
+	- Intel 810
+	- Intel 810E
+	- Intel 810-DC100
+	- Intel 815 Internal graphics only, 100Mhz FSB
+	- Intel 815 Internal graphics only
+	- Intel 815 Internal graphics and AGP
+
+B.  Features
+============
+
+	- Choice of using Discrete Video Timings, VESA Generalized Timing
+	  Formula, or a framebuffer specific database to set the video mode
+
+	- Supports a variable range of horizontal and vertical resolution and
+	  vertical refresh rates if the VESA Generalized Timing Formula is
+	  enabled.
+
+	- Supports color depths of 8, 16, 24 and 32 bits per pixel
+
+	- Supports pseudocolor, directcolor, or truecolor visuals
+
+	- Full and optimized hardware acceleration at 8, 16 and 24 bpp
+
+	- Robust video state save and restore
+
+	- MTRR support
+
+	- Utilizes user-entered monitor specifications to automatically
+	  calculate required video mode parameters.
+
+	- Can concurrently run with xfree86 running with native i810 drivers
+
+	- Hardware Cursor Support
+
+	- Supports EDID probing either by DDC/I2C or through the BIOS
+
+C.  List of available options
+=============================
+
+   a. "video=i810fb"
+	enables the i810 driver
+
+	Recommendation: required
+
+   b. "xres:<value>"
+	select horizontal resolution in pixels. (This parameter will be
+	ignored if 'mode_option' is specified.  See 'o' below).
+
+	Recommendation: user preference
+	(default = 640)
+
+   c. "yres:<value>"
+	select vertical resolution in scanlines. If Discrete Video Timings
+	is enabled, this will be ignored and computed as 3*xres/4.  (This
+	parameter will be ignored if 'mode_option' is specified.  See 'o'
+	below)
+
+	Recommendation: user preference
+	(default = 480)
+
+   d. "vyres:<value>"
+	select virtual vertical resolution in scanlines. If (0) or none
+	is specified, this will be computed against maximum available memory.
+
+	Recommendation: do not set
+	(default = 480)
+
+   e. "vram:<value>"
+	select amount of system RAM in MB to allocate for the video memory
+
+	Recommendation: 1 - 4 MB.
+	(default = 4)
+
+   f. "bpp:<value>"
+	select desired pixel depth
+
+	Recommendation: 8
+	(default = 8)
+
+   g. "hsync1/hsync2:<value>"
+	select the minimum and maximum Horizontal Sync Frequency of the
+	monitor in kHz.  If using a fixed frequency monitor, hsync1 must
+	be equal to hsync2. If EDID probing is successful, these will be
+	ignored and values will be taken from the EDID block.
+
+	Recommendation: check monitor manual for correct values
+	(default = 29/30)
+
+   h. "vsync1/vsync2:<value>"
+	select the minimum and maximum Vertical Sync Frequency of the monitor
+	in Hz. You can also use this option to lock your monitor's refresh
+	rate. If EDID probing is successful, these will be ignored and values
+	will be taken from the EDID block.
+
+	Recommendation: check monitor manual for correct values
+	(default = 60/60)
+
+	IMPORTANT:  If you need to clamp your timings, try to give some
+	leeway for computational errors (over/underflows).  Example: if
+	using vsync1/vsync2 = 60/60, make sure hsync1/hsync2 has at least
+	a 1 unit difference, and vice versa.
+
+   i. "voffset:<value>"
+	select at what offset in MB of the logical memory to allocate the
+	framebuffer memory.  The intent is to avoid the memory blocks
+	used by standard graphics applications (XFree86).  The default
+	offset (16 MB for a 64 MB aperture, 8 MB for a 32 MB aperture) will
+	avoid XFree86's usage and allows up to 7 MB/15 MB of framebuffer
+	memory.  Depending on your usage, adjust the value up or down
+	(0 for maximum usage, 31/63 MB for the least amount).  Note, an
+	arbitrary setting may conflict with XFree86.
+
+	Recommendation: do not set
+	(default = 8 or 16 MB)
+
+   j. "accel"
+	enable text acceleration.  This can be enabled/reenabled anytime
+	by using 'fbset -accel true/false'.
+
+	Recommendation: enable
+	(default = not set)
+
+   k. "mtrr"
+	enable MTRR.  This allows data transfers to the framebuffer memory
+	to occur in bursts which can significantly increase performance.
+	Not very helpful with the i810/i815 because of 'shared memory'.
+
+	Recommendation: do not set
+	(default = not set)
+
+   l. "extvga"
+	if specified, secondary/external VGA output will always be enabled.
+	Useful if the BIOS turns off the VGA port when no monitor is attached.
+	The external VGA monitor can then be attached without rebooting.
+
+	Recommendation: do not set
+	(default = not set)
+
+   m. "sync"
+	Forces the hardware engine to do a "sync" or wait for the hardware
+	to finish before starting another instruction. This will produce a
+	more stable setup, but will be slower.
+
+	Recommendation: do not set
+	(default = not set)
+
+   n. "dcolor"
+	Use directcolor visual instead of truecolor for pixel depths greater
+	than 8 bpp.  Useful for color tuning, such as gamma control.
+
+	Recommendation: do not set
+	(default = not set)
+
+   o. <xres>x<yres>[-<bpp>][@<refresh>]
+	The driver will now accept specification of boot mode option.  If this
+	is specified, the options 'xres' and 'yres' will be ignored. See
+	Documentation/fb/modedb.rst for usage.
+
+D. Kernel booting
+=================
+
+Separate each option/option-pair by commas (,) and the option from its value
+with a colon (:) as in the following::
+
+	video=i810fb:option1,option2:value2
+
+Sample Usage
+------------
+
+In /etc/lilo.conf, add the line::
+
+  append="video=i810fb:vram:2,xres:1024,yres:768,bpp:8,hsync1:30,hsync2:55, \
+	  vsync1:50,vsync2:85,accel,mtrr"
+
+This will initialize the framebuffer to 1024x768 at 8bpp.  The framebuffer
+will use 2 MB of System RAM. MTRR support will be enabled. The refresh rate
+will be computed based on the hsync1/hsync2 and vsync1/vsync2 values.
+
+IMPORTANT:
+  You must include hsync1, hsync2, vsync1 and vsync2 to enable video modes
+  better than 640x480 at 60Hz. HOWEVER, if your chipset/display combination
+  supports I2C and has an EDID block, you can safely exclude hsync1, hsync2,
+  vsync1 and vsync2 parameters.  These parameters will be taken from the EDID
+  block.
+
+E.  Module options
+==================
+
+The module parameters are essentially similar to the kernel
+parameters. The main difference is that you need to include a Boolean value
+(1 for TRUE, and 0 for FALSE) for those options which don't need a value.
+
+Example, to enable MTRR, include "mtrr=1".
+
+Sample Usage
+------------
+
+Using the same setup as described above, load the module like this::
+
+	modprobe i810fb vram=2 xres=1024 bpp=8 hsync1=30 hsync2=55 vsync1=50 \
+		 vsync2=85 accel=1 mtrr=1
+
+Or just add the following to a configuration file in /etc/modprobe.d/::
+
+	options i810fb vram=2 xres=1024 bpp=16 hsync1=30 hsync2=55 vsync1=50 \
+	vsync2=85 accel=1 mtrr=1
+
+and just do a::
+
+	modprobe i810fb
+
+
+F.  Setup
+=========
+
+	a. Do your usual method of configuring the kernel
+
+	   make menuconfig/xconfig/config
+
+	b. Under "Code maturity level options" enable "Prompt for development
+	   and/or incomplete code/drivers".
+
+	c. Enable agpgart support for the Intel 810/815 on-board graphics.
+	   This is required.  The option is under "Character Devices".
+
+	d. Under "Graphics Support", select "Intel 810/815" either statically
+	   or as a module.  Choose "use VESA Generalized Timing Formula" if
+	   you need to maximize the capability of your display.  To be on the
+	   safe side, you can leave this unselected.
+
+	e. If you want support for DDC/I2C probing (Plug and Play Displays),
+	   set 'Enable DDC Support' to 'y'. To make this option appear, set
+	   'use VESA Generalized Timing Formula' to 'y'.
+
+	f. If you want a framebuffer console, enable it under "Console
+	   Drivers".
+
+	g. Compile your kernel.
+
+	h. Load the driver as described in sections D and E.
+
+	i.  Try the DirectFB (http://www.directfb.org) + the i810 gfxdriver
+	    patch to see the chipset in action (or inaction :-).
+
+G.  Acknowledgment:
+===================
+
+	1.  Geert Uytterhoeven - his excellent howto and the virtual
+	    framebuffer driver code made this possible.
+
+	2.  Jeff Hartmann for his agpgart code.
+
+	3.  The X developers.  Insights were provided just by reading the
+	    XFree86 source code.
+
+	4.  Intel(c).  For this value-oriented chipset driver and for
+	    providing documentation.
+
+	5. Matt Sottek.  His inputs and ideas  helped in making some
+	   optimizations possible.
+
+H.  Home Page:
+==============
+
+	A more complete, and probably updated information is provided at
+	http://i810fb.sourceforge.net.
+
+Tony