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, 551 insertions, 0 deletions

diff --git a/drivers/video/fbdev/vfb.c b/drivers/video/fbdev/vfb.c
new file mode 100644
index 000000000..5b7965f36
--- /dev/null
+++ b/drivers/video/fbdev/vfb.c
@@ -0,0 +1,551 @@
+/*
+ *  linux/drivers/video/vfb.c -- Virtual frame buffer device
+ *
+ *      Copyright (C) 2002 James Simmons
+ *
+ *	Copyright (C) 1997 Geert Uytterhoeven
+ *
+ *  This file is subject to the terms and conditions of the GNU General Public
+ *  License. See the file COPYING in the main directory of this archive for
+ *  more details.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+
+#include <linux/fb.h>
+#include <linux/init.h>
+
+    /*
+     *  RAM we reserve for the frame buffer. This defines the maximum screen
+     *  size
+     *
+     *  The default can be overridden if the driver is compiled as a module
+     */
+
+#define VIDEOMEMSIZE	(1*1024*1024)	/* 1 MB */
+
+static void *videomemory;
+static u_long videomemorysize = VIDEOMEMSIZE;
+module_param(videomemorysize, ulong, 0);
+MODULE_PARM_DESC(videomemorysize, "RAM available to frame buffer (in bytes)");
+
+static char *mode_option = NULL;
+module_param(mode_option, charp, 0);
+MODULE_PARM_DESC(mode_option, "Preferred video mode (e.g. 640x480-8@60)");
+
+static const struct fb_videomode vfb_default = {
+	.xres =		640,
+	.yres =		480,
+	.pixclock =	20000,
+	.left_margin =	64,
+	.right_margin =	64,
+	.upper_margin =	32,
+	.lower_margin =	32,
+	.hsync_len =	64,
+	.vsync_len =	2,
+	.vmode =	FB_VMODE_NONINTERLACED,
+};
+
+static struct fb_fix_screeninfo vfb_fix = {
+	.id =		"Virtual FB",
+	.type =		FB_TYPE_PACKED_PIXELS,
+	.visual =	FB_VISUAL_PSEUDOCOLOR,
+	.xpanstep =	1,
+	.ypanstep =	1,
+	.ywrapstep =	1,
+	.accel =	FB_ACCEL_NONE,
+};
+
+static bool vfb_enable __initdata = 0;	/* disabled by default */
+module_param(vfb_enable, bool, 0);
+MODULE_PARM_DESC(vfb_enable, "Enable Virtual FB driver");
+
+static int vfb_check_var(struct fb_var_screeninfo *var,
+			 struct fb_info *info);
+static int vfb_set_par(struct fb_info *info);
+static int vfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
+			 u_int transp, struct fb_info *info);
+static int vfb_pan_display(struct fb_var_screeninfo *var,
+			   struct fb_info *info);
+static int vfb_mmap(struct fb_info *info,
+		    struct vm_area_struct *vma);
+
+static const struct fb_ops vfb_ops = {
+	.owner		= THIS_MODULE,
+	__FB_DEFAULT_SYSMEM_OPS_RDWR,
+	.fb_check_var	= vfb_check_var,
+	.fb_set_par	= vfb_set_par,
+	.fb_setcolreg	= vfb_setcolreg,
+	.fb_pan_display	= vfb_pan_display,
+	__FB_DEFAULT_SYSMEM_OPS_DRAW,
+	.fb_mmap	= vfb_mmap,
+};
+
+    /*
+     *  Internal routines
+     */
+
+static u_long get_line_length(int xres_virtual, int bpp)
+{
+	u_long length;
+
+	length = xres_virtual * bpp;
+	length = (length + 31) & ~31;
+	length >>= 3;
+	return (length);
+}
+
+    /*
+     *  Setting the video mode has been split into two parts.
+     *  First part, xxxfb_check_var, must not write anything
+     *  to hardware, it should only verify and adjust var.
+     *  This means it doesn't alter par but it does use hardware
+     *  data from it to check this var.
+     */
+
+static int vfb_check_var(struct fb_var_screeninfo *var,
+			 struct fb_info *info)
+{
+	u_long line_length;
+
+	/*
+	 *  FB_VMODE_CONUPDATE and FB_VMODE_SMOOTH_XPAN are equal!
+	 *  as FB_VMODE_SMOOTH_XPAN is only used internally
+	 */
+
+	if (var->vmode & FB_VMODE_CONUPDATE) {
+		var->vmode |= FB_VMODE_YWRAP;
+		var->xoffset = info->var.xoffset;
+		var->yoffset = info->var.yoffset;
+	}
+
+	/*
+	 *  Some very basic checks
+	 */
+	if (!var->xres)
+		var->xres = 1;
+	if (!var->yres)
+		var->yres = 1;
+	if (var->xres > var->xres_virtual)
+		var->xres_virtual = var->xres;
+	if (var->yres > var->yres_virtual)
+		var->yres_virtual = var->yres;
+	if (var->bits_per_pixel <= 1)
+		var->bits_per_pixel = 1;
+	else if (var->bits_per_pixel <= 8)
+		var->bits_per_pixel = 8;
+	else if (var->bits_per_pixel <= 16)
+		var->bits_per_pixel = 16;
+	else if (var->bits_per_pixel <= 24)
+		var->bits_per_pixel = 24;
+	else if (var->bits_per_pixel <= 32)
+		var->bits_per_pixel = 32;
+	else
+		return -EINVAL;
+
+	if (var->xres_virtual < var->xoffset + var->xres)
+		var->xres_virtual = var->xoffset + var->xres;
+	if (var->yres_virtual < var->yoffset + var->yres)
+		var->yres_virtual = var->yoffset + var->yres;
+
+	/*
+	 *  Memory limit
+	 */
+	line_length =
+	    get_line_length(var->xres_virtual, var->bits_per_pixel);
+	if (line_length * var->yres_virtual > videomemorysize)
+		return -ENOMEM;
+
+	/*
+	 * Now that we checked it we alter var. The reason being is that the video
+	 * mode passed in might not work but slight changes to it might make it
+	 * work. This way we let the user know what is acceptable.
+	 */
+	switch (var->bits_per_pixel) {
+	case 1:
+	case 8:
+		var->red.offset = 0;
+		var->red.length = 8;
+		var->green.offset = 0;
+		var->green.length = 8;
+		var->blue.offset = 0;
+		var->blue.length = 8;
+		var->transp.offset = 0;
+		var->transp.length = 0;
+		break;
+	case 16:		/* RGBA 5551 */
+		if (var->transp.length) {
+			var->red.offset = 0;
+			var->red.length = 5;
+			var->green.offset = 5;
+			var->green.length = 5;
+			var->blue.offset = 10;
+			var->blue.length = 5;
+			var->transp.offset = 15;
+			var->transp.length = 1;
+		} else {	/* RGB 565 */
+			var->red.offset = 0;
+			var->red.length = 5;
+			var->green.offset = 5;
+			var->green.length = 6;
+			var->blue.offset = 11;
+			var->blue.length = 5;
+			var->transp.offset = 0;
+			var->transp.length = 0;
+		}
+		break;
+	case 24:		/* RGB 888 */
+		var->red.offset = 0;
+		var->red.length = 8;
+		var->green.offset = 8;
+		var->green.length = 8;
+		var->blue.offset = 16;
+		var->blue.length = 8;
+		var->transp.offset = 0;
+		var->transp.length = 0;
+		break;
+	case 32:		/* RGBA 8888 */
+		var->red.offset = 0;
+		var->red.length = 8;
+		var->green.offset = 8;
+		var->green.length = 8;
+		var->blue.offset = 16;
+		var->blue.length = 8;
+		var->transp.offset = 24;
+		var->transp.length = 8;
+		break;
+	}
+	var->red.msb_right = 0;
+	var->green.msb_right = 0;
+	var->blue.msb_right = 0;
+	var->transp.msb_right = 0;
+
+	return 0;
+}
+
+/* This routine actually sets the video mode. It's in here where we
+ * the hardware state info->par and fix which can be affected by the
+ * change in par. For this driver it doesn't do much.
+ */
+static int vfb_set_par(struct fb_info *info)
+{
+	switch (info->var.bits_per_pixel) {
+	case 1:
+		info->fix.visual = FB_VISUAL_MONO01;
+		break;
+	case 8:
+		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
+		break;
+	case 16:
+	case 24:
+	case 32:
+		info->fix.visual = FB_VISUAL_TRUECOLOR;
+		break;
+	}
+
+	info->fix.line_length = get_line_length(info->var.xres_virtual,
+						info->var.bits_per_pixel);
+
+	return 0;
+}
+
+    /*
+     *  Set a single color register. The values supplied are already
+     *  rounded down to the hardware's capabilities (according to the
+     *  entries in the var structure). Return != 0 for invalid regno.
+     */
+
+static int vfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
+			 u_int transp, struct fb_info *info)
+{
+	if (regno >= 256)	/* no. of hw registers */
+		return 1;
+	/*
+	 * Program hardware... do anything you want with transp
+	 */
+
+	/* grayscale works only partially under directcolor */
+	if (info->var.grayscale) {
+		/* grayscale = 0.30*R + 0.59*G + 0.11*B */
+		red = green = blue =
+		    (red * 77 + green * 151 + blue * 28) >> 8;
+	}
+
+	/* Directcolor:
+	 *   var->{color}.offset contains start of bitfield
+	 *   var->{color}.length contains length of bitfield
+	 *   {hardwarespecific} contains width of RAMDAC
+	 *   cmap[X] is programmed to (X << red.offset) | (X << green.offset) | (X << blue.offset)
+	 *   RAMDAC[X] is programmed to (red, green, blue)
+	 *
+	 * Pseudocolor:
+	 *    var->{color}.offset is 0 unless the palette index takes less than
+	 *                        bits_per_pixel bits and is stored in the upper
+	 *                        bits of the pixel value
+	 *    var->{color}.length is set so that 1 << length is the number of available
+	 *                        palette entries
+	 *    cmap is not used
+	 *    RAMDAC[X] is programmed to (red, green, blue)
+	 *
+	 * Truecolor:
+	 *    does not use DAC. Usually 3 are present.
+	 *    var->{color}.offset contains start of bitfield
+	 *    var->{color}.length contains length of bitfield
+	 *    cmap is programmed to (red << red.offset) | (green << green.offset) |
+	 *                      (blue << blue.offset) | (transp << transp.offset)
+	 *    RAMDAC does not exist
+	 */
+#define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16)
+	switch (info->fix.visual) {
+	case FB_VISUAL_TRUECOLOR:
+	case FB_VISUAL_PSEUDOCOLOR:
+		red = CNVT_TOHW(red, info->var.red.length);
+		green = CNVT_TOHW(green, info->var.green.length);
+		blue = CNVT_TOHW(blue, info->var.blue.length);
+		transp = CNVT_TOHW(transp, info->var.transp.length);
+		break;
+	case FB_VISUAL_DIRECTCOLOR:
+		red = CNVT_TOHW(red, 8);	/* expect 8 bit DAC */
+		green = CNVT_TOHW(green, 8);
+		blue = CNVT_TOHW(blue, 8);
+		/* hey, there is bug in transp handling... */
+		transp = CNVT_TOHW(transp, 8);
+		break;
+	}
+#undef CNVT_TOHW
+	/* Truecolor has hardware independent palette */
+	if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
+		u32 v;
+
+		if (regno >= 16)
+			return 1;
+
+		v = (red << info->var.red.offset) |
+		    (green << info->var.green.offset) |
+		    (blue << info->var.blue.offset) |
+		    (transp << info->var.transp.offset);
+		switch (info->var.bits_per_pixel) {
+		case 8:
+			break;
+		case 16:
+			((u32 *) (info->pseudo_palette))[regno] = v;
+			break;
+		case 24:
+		case 32:
+			((u32 *) (info->pseudo_palette))[regno] = v;
+			break;
+		}
+		return 0;
+	}
+	return 0;
+}
+
+    /*
+     *  Pan or Wrap the Display
+     *
+     *  This call looks only at xoffset, yoffset and the FB_VMODE_YWRAP flag
+     */
+
+static int vfb_pan_display(struct fb_var_screeninfo *var,
+			   struct fb_info *info)
+{
+	if (var->vmode & FB_VMODE_YWRAP) {
+		if (var->yoffset >= info->var.yres_virtual ||
+		    var->xoffset)
+			return -EINVAL;
+	} else {
+		if (var->xoffset + info->var.xres > info->var.xres_virtual ||
+		    var->yoffset + info->var.yres > info->var.yres_virtual)
+			return -EINVAL;
+	}
+	info->var.xoffset = var->xoffset;
+	info->var.yoffset = var->yoffset;
+	if (var->vmode & FB_VMODE_YWRAP)
+		info->var.vmode |= FB_VMODE_YWRAP;
+	else
+		info->var.vmode &= ~FB_VMODE_YWRAP;
+	return 0;
+}
+
+    /*
+     *  Most drivers don't need their own mmap function
+     */
+
+static int vfb_mmap(struct fb_info *info,
+		    struct vm_area_struct *vma)
+{
+	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
+
+	return remap_vmalloc_range(vma, (void *)info->fix.smem_start, vma->vm_pgoff);
+}
+
+#ifndef MODULE
+/*
+ * The virtual framebuffer driver is only enabled if explicitly
+ * requested by passing 'video=vfb:' (or any actual options).
+ */
+static int __init vfb_setup(char *options)
+{
+	char *this_opt;
+
+	vfb_enable = 0;
+
+	if (!options)
+		return 1;
+
+	vfb_enable = 1;
+
+	if (!*options)
+		return 1;
+
+	while ((this_opt = strsep(&options, ",")) != NULL) {
+		if (!*this_opt)
+			continue;
+		/* Test disable for backwards compatibility */
+		if (!strcmp(this_opt, "disable"))
+			vfb_enable = 0;
+		else
+			mode_option = this_opt;
+	}
+	return 1;
+}
+#endif  /*  MODULE  */
+
+    /*
+     *  Initialisation
+     */
+
+static int vfb_probe(struct platform_device *dev)
+{
+	struct fb_info *info;
+	unsigned int size = PAGE_ALIGN(videomemorysize);
+	int retval = -ENOMEM;
+
+	/*
+	 * For real video cards we use ioremap.
+	 */
+	if (!(videomemory = vmalloc_32_user(size)))
+		return retval;
+
+	info = framebuffer_alloc(sizeof(u32) * 256, &dev->dev);
+	if (!info)
+		goto err;
+
+	info->flags |= FBINFO_VIRTFB;
+	info->screen_buffer = videomemory;
+	info->fbops = &vfb_ops;
+
+	if (!fb_find_mode(&info->var, info, mode_option,
+			  NULL, 0, &vfb_default, 8)){
+		fb_err(info, "Unable to find usable video mode.\n");
+		retval = -EINVAL;
+		goto err1;
+	}
+
+	vfb_fix.smem_start = (unsigned long) videomemory;
+	vfb_fix.smem_len = videomemorysize;
+	info->fix = vfb_fix;
+	info->pseudo_palette = info->par;
+	info->par = NULL;
+
+	retval = fb_alloc_cmap(&info->cmap, 256, 0);
+	if (retval < 0)
+		goto err1;
+
+	retval = register_framebuffer(info);
+	if (retval < 0)
+		goto err2;
+	platform_set_drvdata(dev, info);
+
+	vfb_set_par(info);
+
+	fb_info(info, "Virtual frame buffer device, using %ldK of video memory\n",
+		videomemorysize >> 10);
+	return 0;
+err2:
+	fb_dealloc_cmap(&info->cmap);
+err1:
+	framebuffer_release(info);
+err:
+	vfree(videomemory);
+	return retval;
+}
+
+static void vfb_remove(struct platform_device *dev)
+{
+	struct fb_info *info = platform_get_drvdata(dev);
+
+	if (info) {
+		unregister_framebuffer(info);
+		vfree(videomemory);
+		fb_dealloc_cmap(&info->cmap);
+		framebuffer_release(info);
+	}
+}
+
+static struct platform_driver vfb_driver = {
+	.probe	= vfb_probe,
+	.remove = vfb_remove,
+	.driver = {
+		.name	= "vfb",
+	},
+};
+
+static struct platform_device *vfb_device;
+
+static int __init vfb_init(void)
+{
+	int ret = 0;
+
+#ifndef MODULE
+	char *option = NULL;
+
+	if (fb_get_options("vfb", &option))
+		return -ENODEV;
+	vfb_setup(option);
+#endif
+
+	if (!vfb_enable)
+		return -ENXIO;
+
+	ret = platform_driver_register(&vfb_driver);
+
+	if (!ret) {
+		vfb_device = platform_device_alloc("vfb", 0);
+
+		if (vfb_device)
+			ret = platform_device_add(vfb_device);
+		else
+			ret = -ENOMEM;
+
+		if (ret) {
+			platform_device_put(vfb_device);
+			platform_driver_unregister(&vfb_driver);
+		}
+	}
+
+	return ret;
+}
+
+module_init(vfb_init);
+
+#ifdef MODULE
+static void __exit vfb_exit(void)
+{
+	platform_device_unregister(vfb_device);
+	platform_driver_unregister(&vfb_driver);
+}
+
+module_exit(vfb_exit);
+
+MODULE_DESCRIPTION("Virtual Frame Buffer driver");
+MODULE_LICENSE("GPL");
+#endif				/* MODULE */