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, 8 deletions

diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c
index a0f3d6c4d39..8308fc7cdc2 100644
--- a/drivers/tty/vt/consolemap.c
+++ b/drivers/tty/vt/consolemap.c
@@ -516,6 +516,7 @@ int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list)
 	int err = 0, err1, i;
 	struct uni_pagedir *p, *q;
 
+	/* Save original vc_unipagdir_loc in case we allocate a new one */
 	p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
 	if (p->readonly) return -EIO;
 	
@@ -528,26 +529,57 @@ int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list)
 		err1 = con_clear_unimap(vc, NULL);
 		if (err1) return err1;
 		
+		/*
+		 * Since refcount was > 1, con_clear_unimap() allocated a
+		 * a new uni_pagedir for this vc.  Re: p != q
+		 */
 		q = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
-		for (i = 0, l = 0; i < 32; i++)
+
+		/*
+		 * uni_pgdir is a 32*32*64 table with rows allocated
+		 * when its first entry is added.  The unicode value must
+		 * still be incremented for empty rows.  We are copying
+		 * entries from "p" (old) to "q" (new).
+		 */
+		l = 0;		/* unicode value */
+		for (i = 0; i < 32; i++)
 		if ((p1 = p->uni_pgdir[i]))
 			for (j = 0; j < 32; j++)
-			if ((p2 = p1[j]))
+			if ((p2 = p1[j])) {
 				for (k = 0; k < 64; k++, l++)
 				if (p2[k] != 0xffff) {
+					/*
+					 * Found one, copy entry for unicode
+					 * l with fontpos value p2[k].
+					 */
 					err1 = con_insert_unipair(q, l, p2[k]);
 					if (err1) {
 						p->refcount++;
 						*vc->vc_uni_pagedir_loc = (unsigned long)p;
 						con_release_unimap(q);
 						kfree(q);
-						return err1; 
+						return err1;
 					}
-              			}
-              	p = q;
-	} else if (p == dflt)
+				}
+			} else {
+				/* Account for row of 64 empty entries */
+				l += 64;
+			}
+		else
+			/* Account for empty table */
+			l += 32 * 64;
+
+		/*
+		 * Finished copying font table, set vc_uni_pagedir to new table
+		 */
+		p = q;
+	} else if (p == dflt) {
 		dflt = NULL;
-	
+	}
+
+	/*
+	 * Insert user specified unicode pairs into new table.
+	 */
 	while (ct--) {
 		unsigned short unicode, fontpos;
 		__get_user(unicode, &list->unicode);
@@ -557,11 +589,14 @@ int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list)
 		list++;
 	}
 	
+	/*
+	 * Merge with fontmaps of any other virtual consoles.
+	 */
 	if (con_unify_unimap(vc, p))
 		return err;
 
 	for (i = 0; i <= 3; i++)
-		set_inverse_transl(vc, p, i); /* Update all inverse translations */
+		set_inverse_transl(vc, p, i); /* Update inverse translations */
 	set_inverse_trans_unicode(vc, p);
   
 	return err;