Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 43 insertions, 15 deletions

diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
index 7a0a12ae545..8e9b4be97a2 100644
--- a/drivers/tty/vt/selection.c
+++ b/drivers/tty/vt/selection.c
@@ -30,6 +30,7 @@
 
 extern void poke_blanked_console(void);
 
+/* FIXME: all this needs locking */
 /* Variables for selection control. */
 /* Use a dynamic buffer, instead of static (Dec 1994) */
 struct vc_data *sel_cons;		/* must not be deallocated */
@@ -61,10 +62,14 @@ sel_pos(int n)
 				use_unicode);
 }
 
-/* remove the current selection highlight, if any,
-   from the console holding the selection. */
-void
-clear_selection(void) {
+/**
+ *	clear_selection		-	remove current selection
+ *
+ *	Remove the current selection highlight, if any from the console
+ *	holding the selection. The caller must hold the console lock.
+ */
+void clear_selection(void)
+{
 	highlight_pointer(-1); /* hide the pointer */
 	if (sel_start != -1) {
 		highlight(sel_start, sel_end);
@@ -74,7 +79,7 @@ clear_selection(void) {
 
 /*
  * User settable table: what characters are to be considered alphabetic?
- * 256 bits
+ * 256 bits. Locked by the console lock.
  */
 static u32 inwordLut[8]={
   0x00000000, /* control chars     */
@@ -91,10 +96,20 @@ static inline int inword(const u16 c) {
 	return c > 0xff || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
 }
 
-/* set inwordLut contents. Invoked by ioctl(). */
+/**
+ *	set loadlut		-	load the LUT table
+ *	@p: user table
+ *
+ *	Load the LUT table from user space. The caller must hold the console
+ *	lock. Make a temporary copy so a partial update doesn't make a mess.
+ */
 int sel_loadlut(char __user *p)
 {
-	return copy_from_user(inwordLut, (u32 __user *)(p+4), 32) ? -EFAULT : 0;
+	u32 tmplut[8];
+	if (copy_from_user(tmplut, (u32 __user *)(p+4), 32))
+		return -EFAULT;
+	memcpy(inwordLut, tmplut, 32);
+	return 0;
 }
 
 /* does screen address p correspond to character at LH/RH edge of screen? */
@@ -130,7 +145,16 @@ static int store_utf8(u16 c, char *p)
     	}
 }
 
-/* set the current selection. Invoked by ioctl() or by kernel code. */
+/**
+ *	set_selection		- 	set the current selection.
+ *	@sel: user selection info
+ *	@tty: the console tty
+ *
+ *	Invoked by the ioctl handle for the vt layer.
+ *
+ *	The entire selection process is managed under the console_lock. It's
+ *	 a lot under the lock but its hardly a performance path
+ */
 int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
 {
 	struct vc_data *vc = vc_cons[fg_console].d;
@@ -138,7 +162,7 @@ int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *t
 	char *bp, *obp;
 	int i, ps, pe, multiplier;
 	u16 c;
-	struct kbd_struct *kbd = kbd_table + fg_console;
+	int mode;
 
 	poke_blanked_console();
 
@@ -182,7 +206,11 @@ int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *t
 		clear_selection();
 		sel_cons = vc_cons[fg_console].d;
 	}
-	use_unicode = kbd && kbd->kbdmode == VC_UNICODE;
+	mode = vt_do_kdgkbmode(fg_console);
+	if (mode == K_UNICODE)
+		use_unicode = 1;
+	else
+		use_unicode = 0;
 
 	switch (sel_mode)
 	{
@@ -302,7 +330,8 @@ int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *t
  * queue of the tty associated with the current console.
  * Invoked by ioctl().
  *
- * Locking: always called with BTM from vt_ioctl
+ * Locking: called without locks. Calls the ldisc wrongly with
+ * unsafe methods,
  */
 int paste_selection(struct tty_struct *tty)
 {
@@ -317,13 +346,12 @@ int paste_selection(struct tty_struct *tty)
 	poke_blanked_console();
 	console_unlock();
 
+	/* FIXME: wtf is this supposed to achieve ? */
 	ld = tty_ldisc_ref(tty);
-	if (!ld) {
-		tty_unlock();
+	if (!ld)
 		ld = tty_ldisc_ref_wait(tty);
-		tty_lock();
-	}
 
+	/* FIXME: this is completely unsafe */
 	add_wait_queue(&vc->paste_wait, &wait);
 	while (sel_buffer && sel_buffer_lth > pasted) {
 		set_current_state(TASK_INTERRUPTIBLE);