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, 297 insertions, 0 deletions

diff --git a/Documentation/fb/viafb.rst b/Documentation/fb/viafb.rst
new file mode 100644
index 000000000..8eb7a3bb0
--- /dev/null
+++ b/Documentation/fb/viafb.rst
@@ -0,0 +1,297 @@
+=======================================================
+VIA Integration Graphic Chip Console Framebuffer Driver
+=======================================================
+
+Platform
+--------
+    The console framebuffer driver is for graphics chips of
+    VIA UniChrome Family
+    (CLE266, PM800 / CN400 / CN300,
+    P4M800CE / P4M800Pro / CN700 / VN800,
+    CX700 / VX700, K8M890, P4M890,
+    CN896 / P4M900, VX800, VX855)
+
+Driver features
+---------------
+    Device: CRT, LCD, DVI
+
+    Support viafb_mode::
+
+	CRT:
+	    640x480(60, 75, 85, 100, 120 Hz), 720x480(60 Hz),
+	    720x576(60 Hz), 800x600(60, 75, 85, 100, 120 Hz),
+	    848x480(60 Hz), 856x480(60 Hz), 1024x512(60 Hz),
+	    1024x768(60, 75, 85, 100 Hz), 1152x864(75 Hz),
+	    1280x768(60 Hz), 1280x960(60 Hz), 1280x1024(60, 75, 85 Hz),
+	    1440x1050(60 Hz), 1600x1200(60, 75 Hz), 1280x720(60 Hz),
+	    1920x1080(60 Hz), 1400x1050(60 Hz), 800x480(60 Hz)
+
+    color depth: 8 bpp, 16 bpp, 32 bpp supports.
+
+    Support 2D hardware accelerator.
+
+Using the viafb module
+----------------------
+    Start viafb with default settings::
+
+	#modprobe viafb
+
+    Start viafb with user options::
+
+	#modprobe viafb viafb_mode=800x600 viafb_bpp=16 viafb_refresh=60
+		  viafb_active_dev=CRT+DVI viafb_dvi_port=DVP1
+		  viafb_mode1=1024x768 viafb_bpp=16 viafb_refresh1=60
+		  viafb_SAMM_ON=1
+
+    viafb_mode:
+	- 640x480 (default)
+	- 720x480
+	- 800x600
+	- 1024x768
+
+    viafb_bpp:
+	- 8, 16, 32 (default:32)
+
+    viafb_refresh:
+	- 60, 75, 85, 100, 120 (default:60)
+
+    viafb_lcd_dsp_method:
+	- 0 : expansion (default)
+	- 1 : centering
+
+    viafb_lcd_mode:
+	0 : LCD panel with LSB data format input (default)
+	1 : LCD panel with MSB data format input
+
+    viafb_lcd_panel_id:
+	- 0 : Resolution: 640x480, Channel: single, Dithering: Enable
+	- 1 : Resolution: 800x600, Channel: single, Dithering: Enable
+	- 2 : Resolution: 1024x768, Channel: single, Dithering: Enable (default)
+	- 3 : Resolution: 1280x768, Channel: single, Dithering: Enable
+	- 4 : Resolution: 1280x1024, Channel: dual, Dithering: Enable
+	- 5 : Resolution: 1400x1050, Channel: dual, Dithering: Enable
+	- 6 : Resolution: 1600x1200, Channel: dual, Dithering: Enable
+
+	- 8 : Resolution: 800x480, Channel: single, Dithering: Enable
+	- 9 : Resolution: 1024x768, Channel: dual, Dithering: Enable
+	- 10: Resolution: 1024x768, Channel: single, Dithering: Disable
+	- 11: Resolution: 1024x768, Channel: dual, Dithering: Disable
+	- 12: Resolution: 1280x768, Channel: single, Dithering: Disable
+	- 13: Resolution: 1280x1024, Channel: dual, Dithering: Disable
+	- 14: Resolution: 1400x1050, Channel: dual, Dithering: Disable
+	- 15: Resolution: 1600x1200, Channel: dual, Dithering: Disable
+	- 16: Resolution: 1366x768, Channel: single, Dithering: Disable
+	- 17: Resolution: 1024x600, Channel: single, Dithering: Enable
+	- 18: Resolution: 1280x768, Channel: dual, Dithering: Enable
+	- 19: Resolution: 1280x800, Channel: single, Dithering: Enable
+
+    viafb_accel:
+	- 0 : No 2D Hardware Acceleration
+	- 1 : 2D Hardware Acceleration (default)
+
+    viafb_SAMM_ON:
+	- 0 : viafb_SAMM_ON disable (default)
+	- 1 : viafb_SAMM_ON enable
+
+    viafb_mode1: (secondary display device)
+	- 640x480 (default)
+	- 720x480
+	- 800x600
+	- 1024x768
+
+    viafb_bpp1: (secondary display device)
+	- 8, 16, 32 (default:32)
+
+    viafb_refresh1: (secondary display device)
+	- 60, 75, 85, 100, 120 (default:60)
+
+    viafb_active_dev:
+	This option is used to specify active devices.(CRT, DVI, CRT+LCD...)
+	DVI stands for DVI or HDMI, E.g., If you want to enable HDMI,
+	set viafb_active_dev=DVI. In SAMM case, the previous of
+	viafb_active_dev is primary device, and the following is
+	secondary device.
+
+	For example:
+
+	To enable one device, such as DVI only, we can use::
+
+	    modprobe viafb viafb_active_dev=DVI
+
+	To enable two devices, such as CRT+DVI::
+
+	    modprobe viafb viafb_active_dev=CRT+DVI;
+
+	For DuoView case, we can use::
+
+	    modprobe viafb viafb_active_dev=CRT+DVI
+
+	OR::
+
+	    modprobe viafb viafb_active_dev=DVI+CRT...
+
+	For SAMM case:
+
+	If CRT is primary and DVI is secondary, we should use::
+
+	    modprobe viafb viafb_active_dev=CRT+DVI viafb_SAMM_ON=1...
+
+	If DVI is primary and CRT is secondary, we should use::
+
+	    modprobe viafb viafb_active_dev=DVI+CRT viafb_SAMM_ON=1...
+
+    viafb_display_hardware_layout:
+	This option is used to specify display hardware layout for CX700 chip.
+
+	- 1 : LCD only
+	- 2 : DVI only
+	- 3 : LCD+DVI (default)
+	- 4 : LCD1+LCD2 (internal + internal)
+	- 16: LCD1+ExternalLCD2 (internal + external)
+
+    viafb_second_size:
+	This option is used to set second device memory size(MB) in SAMM case.
+	The minimal size is 16.
+
+    viafb_platform_epia_dvi:
+	This option is used to enable DVI on EPIA - M
+
+	- 0 : No DVI on EPIA - M (default)
+	- 1 : DVI on EPIA - M
+
+    viafb_bus_width:
+	When using 24 - Bit Bus Width Digital Interface,
+	this option should be set.
+
+	- 12: 12-Bit LVDS or 12-Bit TMDS (default)
+	- 24: 24-Bit LVDS or 24-Bit TMDS
+
+    viafb_device_lcd_dualedge:
+	When using Dual Edge Panel, this option should be set.
+
+	- 0 : No Dual Edge Panel (default)
+	- 1 : Dual Edge Panel
+
+    viafb_lcd_port:
+	This option is used to specify LCD output port,
+	available values are "DVP0" "DVP1" "DFP_HIGHLOW" "DFP_HIGH" "DFP_LOW".
+
+	for external LCD + external DVI on CX700(External LCD is on DVP0),
+	we should use::
+
+	    modprobe viafb viafb_lcd_port=DVP0...
+
+Notes:
+    1. CRT may not display properly for DuoView CRT & DVI display at
+       the "640x480" PAL mode with DVI overscan enabled.
+    2. SAMM stands for single adapter multi monitors. It is different from
+       multi-head since SAMM support multi monitor at driver layers, thus fbcon
+       layer doesn't even know about it; SAMM's second screen doesn't have a
+       device node file, thus a user mode application can't access it directly.
+       When SAMM is enabled, viafb_mode and viafb_mode1, viafb_bpp and
+       viafb_bpp1, viafb_refresh and viafb_refresh1 can be different.
+    3. When console is depending on viafbinfo1, dynamically change resolution
+       and bpp, need to call VIAFB specified ioctl interface VIAFB_SET_DEVICE
+       instead of calling common ioctl function FBIOPUT_VSCREENINFO since
+       viafb doesn't support multi-head well, or it will cause screen crush.
+
+
+Configure viafb with "fbset" tool
+---------------------------------
+
+    "fbset" is an inbox utility of Linux.
+
+    1. Inquire current viafb information, type::
+
+	   # fbset -i
+
+    2. Set various resolutions and viafb_refresh rates::
+
+	   # fbset <resolution-vertical_sync>
+
+       example::
+
+	   # fbset "1024x768-75"
+
+       or::
+
+	   # fbset -g 1024 768 1024 768 32
+
+       Check the file "/etc/fb.modes" to find display modes available.
+
+    3. Set the color depth::
+
+	   # fbset -depth <value>
+
+       example::
+
+	   # fbset -depth 16
+
+
+Configure viafb via /proc
+-------------------------
+    The following files exist in /proc/viafb
+
+    supported_output_devices
+	This read-only file contains a full ',' separated list containing all
+	output devices that could be available on your platform. It is likely
+	that not all of those have a connector on your hardware but it should
+	provide a good starting point to figure out which of those names match
+	a real connector.
+
+	Example::
+
+		# cat /proc/viafb/supported_output_devices
+
+    iga1/output_devices, iga2/output_devices
+	These two files are readable and writable. iga1 and iga2 are the two
+	independent units that produce the screen image. Those images can be
+	forwarded to one or more output devices. Reading those files is a way
+	to query which output devices are currently used by an iga.
+
+	Example::
+
+		# cat /proc/viafb/iga1/output_devices
+
+	If there are no output devices printed the output of this iga is lost.
+	This can happen for example if only one (the other) iga is used.
+	Writing to these files allows adjusting the output devices during
+	runtime. One can add new devices, remove existing ones or switch
+	between igas. Essentially you can write a ',' separated list of device
+	names (or a single one) in the same format as the output to those
+	files. You can add a '+' or '-' as a prefix allowing simple addition
+	and removal of devices. So a prefix '+' adds the devices from your list
+	to the already existing ones, '-' removes the listed devices from the
+	existing ones and if no prefix is given it replaces all existing ones
+	with the listed ones. If you remove devices they are expected to turn
+	off. If you add devices that are already part of the other iga they are
+	removed there and added to the new one.
+
+	Examples:
+
+	Add CRT as output device to iga1::
+
+		# echo +CRT > /proc/viafb/iga1/output_devices
+
+	Remove (turn off) DVP1 and LVDS1 as output devices of iga2::
+
+		# echo -DVP1,LVDS1 > /proc/viafb/iga2/output_devices
+
+	Replace all iga1 output devices by CRT::
+
+		# echo CRT > /proc/viafb/iga1/output_devices
+
+
+Bootup with viafb
+-----------------
+
+Add the following line to your grub.conf::
+
+    append = "video=viafb:viafb_mode=1024x768,viafb_bpp=32,viafb_refresh=85"
+
+
+VIA Framebuffer modes
+=====================
+
+.. include:: viafb.modes
+   :literal: