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, 173 insertions, 0 deletions

diff --git a/Documentation/fb/pxafb.rst b/Documentation/fb/pxafb.rst
new file mode 100644
index 000000000..90177f5e7
--- /dev/null
+++ b/Documentation/fb/pxafb.rst
@@ -0,0 +1,173 @@
+================================
+Driver for PXA25x LCD controller
+================================
+
+The driver supports the following options, either via
+options=<OPTIONS> when modular or video=pxafb:<OPTIONS> when built in.
+
+For example::
+
+	modprobe pxafb options=vmem:2M,mode:640x480-8,passive
+
+or on the kernel command line::
+
+	video=pxafb:vmem:2M,mode:640x480-8,passive
+
+vmem: VIDEO_MEM_SIZE
+
+	Amount of video memory to allocate (can be suffixed with K or M
+	for kilobytes or megabytes)
+
+mode:XRESxYRES[-BPP]
+
+	XRES == LCCR1_PPL + 1
+
+	YRES == LLCR2_LPP + 1
+
+		The resolution of the display in pixels
+
+	BPP == The bit depth. Valid values are 1, 2, 4, 8 and 16.
+
+pixclock:PIXCLOCK
+
+	Pixel clock in picoseconds
+
+left:LEFT == LCCR1_BLW + 1
+
+right:RIGHT == LCCR1_ELW + 1
+
+hsynclen:HSYNC == LCCR1_HSW + 1
+
+upper:UPPER == LCCR2_BFW
+
+lower:LOWER == LCCR2_EFR
+
+vsynclen:VSYNC == LCCR2_VSW + 1
+
+	Display margins and sync times
+
+color | mono => LCCR0_CMS
+
+	umm...
+
+active | passive => LCCR0_PAS
+
+	Active (TFT) or Passive (STN) display
+
+single | dual => LCCR0_SDS
+
+	Single or dual panel passive display
+
+4pix | 8pix => LCCR0_DPD
+
+	4 or 8 pixel monochrome single panel data
+
+hsync:HSYNC, vsync:VSYNC
+
+	Horizontal and vertical sync. 0 => active low, 1 => active
+	high.
+
+dpc:DPC
+
+	Double pixel clock. 1=>true, 0=>false
+
+outputen:POLARITY
+
+	Output Enable Polarity. 0 => active low, 1 => active high
+
+pixclockpol:POLARITY
+
+	pixel clock polarity
+	0 => falling edge, 1 => rising edge
+
+
+Overlay Support for PXA27x and later LCD controllers
+====================================================
+
+  PXA27x and later processors support overlay1 and overlay2 on-top of the
+  base framebuffer (although under-neath the base is also possible). They
+  support palette and no-palette RGB formats, as well as YUV formats (only
+  available on overlay2). These overlays have dedicated DMA channels and
+  behave in a similar way as a framebuffer.
+
+  However, there are some differences between these overlay framebuffers
+  and normal framebuffers, as listed below:
+
+  1. overlay can start at a 32-bit word aligned position within the base
+     framebuffer, which means they have a start (x, y). This information
+     is encoded into var->nonstd (no, var->xoffset and var->yoffset are
+     not for such purpose).
+
+  2. overlay framebuffer is allocated dynamically according to specified
+     'struct fb_var_screeninfo', the amount is decided by::
+
+	var->xres_virtual * var->yres_virtual * bpp
+
+     bpp = 16 -- for RGB565 or RGBT555
+
+     bpp = 24 -- for YUV444 packed
+
+     bpp = 24 -- for YUV444 planar
+
+     bpp = 16 -- for YUV422 planar (1 pixel = 1 Y + 1/2 Cb + 1/2 Cr)
+
+     bpp = 12 -- for YUV420 planar (1 pixel = 1 Y + 1/4 Cb + 1/4 Cr)
+
+     NOTE:
+
+     a. overlay does not support panning in x-direction, thus
+	var->xres_virtual will always be equal to var->xres
+
+     b. line length of overlay(s) must be on a 32-bit word boundary,
+	for YUV planar modes, it is a requirement for the component
+	with minimum bits per pixel,  e.g. for YUV420, Cr component
+	for one pixel is actually 2-bits, it means the line length
+	should be a multiple of 16-pixels
+
+     c. starting horizontal position (XPOS) should start on a 32-bit
+	word boundary, otherwise the fb_check_var() will just fail.
+
+     d. the rectangle of the overlay should be within the base plane,
+	otherwise fail
+
+     Applications should follow the sequence below to operate an overlay
+     framebuffer:
+
+	 a. open("/dev/fb[1-2]", ...)
+	 b. ioctl(fd, FBIOGET_VSCREENINFO, ...)
+	 c. modify 'var' with desired parameters:
+
+	    1) var->xres and var->yres
+	    2) larger var->yres_virtual if more memory is required,
+	       usually for double-buffering
+	    3) var->nonstd for starting (x, y) and color format
+	    4) var->{red, green, blue, transp} if RGB mode is to be used
+
+	 d. ioctl(fd, FBIOPUT_VSCREENINFO, ...)
+	 e. ioctl(fd, FBIOGET_FSCREENINFO, ...)
+	 f. mmap
+	 g. ...
+
+  3. for YUV planar formats, these are actually not supported within the
+     framebuffer framework, application has to take care of the offsets
+     and lengths of each component within the framebuffer.
+
+  4. var->nonstd is used to pass starting (x, y) position and color format,
+     the detailed bit fields are shown below::
+
+      31                23  20         10          0
+       +-----------------+---+----------+----------+
+       |  ... unused ... |FOR|   XPOS   |   YPOS   |
+       +-----------------+---+----------+----------+
+
+     FOR  - color format, as defined by OVERLAY_FORMAT_* in pxafb.h
+
+	  - 0 - RGB
+	  - 1 - YUV444 PACKED
+	  - 2 - YUV444 PLANAR
+	  - 3 - YUV422 PLANAR
+	  - 4 - YUR420 PLANAR
+
+     XPOS - starting horizontal position
+
+     YPOS - starting vertical position