Merge "Merge android-4.4.167 (ad9ce19) into msm-4.4"

2 files changed, 12 insertions, 4 deletions

diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c
index 2aed4a33521b..61cd704a21c8 100644
--- a/kernel/debug/kdb/kdb_support.c
+++ b/kernel/debug/kdb/kdb_support.c
@@ -129,13 +129,13 @@ int kdbnearsym(unsigned long addr, kdb_symtab_t *symtab)
 		}
 		if (i >= ARRAY_SIZE(kdb_name_table)) {
 			debug_kfree(kdb_name_table[0]);
-			memcpy(kdb_name_table, kdb_name_table+1,
+			memmove(kdb_name_table, kdb_name_table+1,
 			       sizeof(kdb_name_table[0]) *
 			       (ARRAY_SIZE(kdb_name_table)-1));
 		} else {
 			debug_kfree(knt1);
 			knt1 = kdb_name_table[i];
-			memcpy(kdb_name_table+i, kdb_name_table+i+1,
+			memmove(kdb_name_table+i, kdb_name_table+i+1,
 			       sizeof(kdb_name_table[0]) *
 			       (ARRAY_SIZE(kdb_name_table)-i-1));
 		}
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 7b1b772ab1ce..d8fc54eef51c 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -606,7 +606,7 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file,
 	BUG_ON((uprobe->offset & ~PAGE_MASK) +
 			UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
 
-	smp_wmb(); /* pairs with rmb() in find_active_uprobe() */
+	smp_wmb(); /* pairs with the smp_rmb() in handle_swbp() */
 	set_bit(UPROBE_COPY_INSN, &uprobe->flags);
 
  out:
@@ -1891,10 +1891,18 @@ static void handle_swbp(struct pt_regs *regs)
 	 * After we hit the bp, _unregister + _register can install the
 	 * new and not-yet-analyzed uprobe at the same address, restart.
 	 */
-	smp_rmb(); /* pairs with wmb() in install_breakpoint() */
 	if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags)))
 		goto out;
 
+	/*
+	 * Pairs with the smp_wmb() in prepare_uprobe().
+	 *
+	 * Guarantees that if we see the UPROBE_COPY_INSN bit set, then
+	 * we must also see the stores to &uprobe->arch performed by the
+	 * prepare_uprobe() call.
+	 */
+	smp_rmb();
+
 	/* Tracing handlers use ->utask to communicate with fetch methods */
 	if (!get_utask())
 		goto out;