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, 240 insertions, 0 deletions

diff --git a/drivers/video/fbdev/bt431.h b/drivers/video/fbdev/bt431.h
new file mode 100644
index 000000000..3929602f5
--- /dev/null
+++ b/drivers/video/fbdev/bt431.h
@@ -0,0 +1,240 @@
+/*
+ *	linux/drivers/video/bt431.h
+ *
+ *	Copyright 2003  Thiemo Seufer <seufer@csv.ica.uni-stuttgart.de>
+ *	Copyright 2016  Maciej W. Rozycki <macro@linux-mips.org>
+ *
+ *	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/types.h>
+
+#define BT431_CURSOR_SIZE	64
+
+/*
+ * Bt431 cursor generator registers, 32-bit aligned.
+ * Two twin Bt431 are used on the DECstation's PMAG-AA.
+ */
+struct bt431_regs {
+	volatile u16 addr_lo;
+	u16 pad0;
+	volatile u16 addr_hi;
+	u16 pad1;
+	volatile u16 addr_cmap;
+	u16 pad2;
+	volatile u16 addr_reg;
+	u16 pad3;
+};
+
+static inline u16 bt431_set_value(u8 val)
+{
+	return ((val << 8) | (val & 0xff)) & 0xffff;
+}
+
+static inline u8 bt431_get_value(u16 val)
+{
+	return val & 0xff;
+}
+
+/*
+ * Additional registers addressed indirectly.
+ */
+#define BT431_REG_CMD		0x0000
+#define BT431_REG_CXLO		0x0001
+#define BT431_REG_CXHI		0x0002
+#define BT431_REG_CYLO		0x0003
+#define BT431_REG_CYHI		0x0004
+#define BT431_REG_WXLO		0x0005
+#define BT431_REG_WXHI		0x0006
+#define BT431_REG_WYLO		0x0007
+#define BT431_REG_WYHI		0x0008
+#define BT431_REG_WWLO		0x0009
+#define BT431_REG_WWHI		0x000a
+#define BT431_REG_WHLO		0x000b
+#define BT431_REG_WHHI		0x000c
+
+#define BT431_REG_CRAM_BASE	0x0000
+#define BT431_REG_CRAM_END	0x01ff
+
+/*
+ * Command register.
+ */
+#define BT431_CMD_CURS_ENABLE	0x40
+#define BT431_CMD_XHAIR_ENABLE	0x20
+#define BT431_CMD_OR_CURSORS	0x10
+#define BT431_CMD_XOR_CURSORS	0x00
+#define BT431_CMD_1_1_MUX	0x00
+#define BT431_CMD_4_1_MUX	0x04
+#define BT431_CMD_5_1_MUX	0x08
+#define BT431_CMD_xxx_MUX	0x0c
+#define BT431_CMD_THICK_1	0x00
+#define BT431_CMD_THICK_3	0x01
+#define BT431_CMD_THICK_5	0x02
+#define BT431_CMD_THICK_7	0x03
+
+static inline void bt431_select_reg(struct bt431_regs *regs, int ir)
+{
+	/*
+	 * The compiler splits the write in two bytes without these
+	 * helper variables.
+	 */
+	volatile u16 *lo = &(regs->addr_lo);
+	volatile u16 *hi = &(regs->addr_hi);
+
+	mb();
+	*lo = bt431_set_value(ir & 0xff);
+	wmb();
+	*hi = bt431_set_value((ir >> 8) & 0xff);
+}
+
+/* Autoincrement read/write. */
+static inline u8 bt431_read_reg_inc(struct bt431_regs *regs)
+{
+	/*
+	 * The compiler splits the write in two bytes without the
+	 * helper variable.
+	 */
+	volatile u16 *r = &(regs->addr_reg);
+
+	mb();
+	return bt431_get_value(*r);
+}
+
+static inline void bt431_write_reg_inc(struct bt431_regs *regs, u8 value)
+{
+	/*
+	 * The compiler splits the write in two bytes without the
+	 * helper variable.
+	 */
+	volatile u16 *r = &(regs->addr_reg);
+
+	mb();
+	*r = bt431_set_value(value);
+}
+
+static inline u8 bt431_read_reg(struct bt431_regs *regs, int ir)
+{
+	bt431_select_reg(regs, ir);
+	return bt431_read_reg_inc(regs);
+}
+
+static inline void bt431_write_reg(struct bt431_regs *regs, int ir, u8 value)
+{
+	bt431_select_reg(regs, ir);
+	bt431_write_reg_inc(regs, value);
+}
+
+/* Autoincremented read/write for the cursor map. */
+static inline u16 bt431_read_cmap_inc(struct bt431_regs *regs)
+{
+	/*
+	 * The compiler splits the write in two bytes without the
+	 * helper variable.
+	 */
+	volatile u16 *r = &(regs->addr_cmap);
+
+	mb();
+	return *r;
+}
+
+static inline void bt431_write_cmap_inc(struct bt431_regs *regs, u16 value)
+{
+	/*
+	 * The compiler splits the write in two bytes without the
+	 * helper variable.
+	 */
+	volatile u16 *r = &(regs->addr_cmap);
+
+	mb();
+	*r = value;
+}
+
+static inline u16 bt431_read_cmap(struct bt431_regs *regs, int cr)
+{
+	bt431_select_reg(regs, cr);
+	return bt431_read_cmap_inc(regs);
+}
+
+static inline void bt431_write_cmap(struct bt431_regs *regs, int cr, u16 value)
+{
+	bt431_select_reg(regs, cr);
+	bt431_write_cmap_inc(regs, value);
+}
+
+static inline void bt431_enable_cursor(struct bt431_regs *regs)
+{
+	bt431_write_reg(regs, BT431_REG_CMD,
+			BT431_CMD_CURS_ENABLE | BT431_CMD_OR_CURSORS
+			| BT431_CMD_4_1_MUX | BT431_CMD_THICK_1);
+}
+
+static inline void bt431_erase_cursor(struct bt431_regs *regs)
+{
+	bt431_write_reg(regs, BT431_REG_CMD, BT431_CMD_4_1_MUX);
+}
+
+static inline void bt431_position_cursor(struct bt431_regs *regs, u16 x, u16 y)
+{
+	/*
+	 * Magic from the MACH sources.
+	 *
+	 * Cx = x + D + H - P
+	 *  P = 37 if 1:1, 52 if 4:1, 57 if 5:1
+	 *  D = pixel skew between outdata and external data
+	 *  H = pixels between HSYNCH falling and active video
+	 *
+	 * Cy = y + V - 32
+	 *  V = scanlines between HSYNCH falling, two or more
+	 *      clocks after VSYNCH falling, and active video
+	 */
+	x += 412 - 52;
+	y += 68 - 32;
+
+	/* Use autoincrement. */
+	bt431_select_reg(regs, BT431_REG_CXLO);
+	bt431_write_reg_inc(regs, x & 0xff); /* BT431_REG_CXLO */
+	bt431_write_reg_inc(regs, (x >> 8) & 0x0f); /* BT431_REG_CXHI */
+	bt431_write_reg_inc(regs, y & 0xff); /* BT431_REG_CYLO */
+	bt431_write_reg_inc(regs, (y >> 8) & 0x0f); /* BT431_REG_CYHI */
+}
+
+static inline void bt431_set_cursor(struct bt431_regs *regs,
+				    const char *data, const char *mask,
+				    u16 rop, u16 width, u16 height)
+{
+	u16 x, y;
+	int i;
+
+	i = 0;
+	width = DIV_ROUND_UP(width, 8);
+	bt431_select_reg(regs, BT431_REG_CRAM_BASE);
+	for (y = 0; y < BT431_CURSOR_SIZE; y++)
+		for (x = 0; x < BT431_CURSOR_SIZE / 8; x++) {
+			u16 val = 0;
+
+			if (y < height && x < width) {
+				val = mask[i];
+				if (rop == ROP_XOR)
+					val = (val << 8) | (val ^ data[i]);
+				else
+					val = (val << 8) | (val & data[i]);
+				i++;
+			}
+			bt431_write_cmap_inc(regs, val);
+		}
+}
+
+static inline void bt431_init_cursor(struct bt431_regs *regs)
+{
+	/* no crosshair window */
+	bt431_select_reg(regs, BT431_REG_WXLO);
+	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WXLO */
+	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WXHI */
+	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WYLO */
+	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WYHI */
+	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WWLO */
+	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WWHI */
+	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WHLO */
+	bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WHHI */
+}