From: Yinghai Lu <yinghai@kernel.org>
Date: Tue, 2 Mar 2010 02:48:52 +0000 (-0800)
Subject: early_res: Need to save the allocation name in drop_range_partial()
X-Git-Tag: firefly_0821_release~9833^2~3040^2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=dce46a04d55d6358d2d4ab44a4946a19f9425fe2;p=firefly-linux-kernel-4.4.55.git

early_res: Need to save the allocation name in drop_range_partial()

During free_early_partial(), reserve_early_without_check() could end
extending the early_res area from __check_and_double_early_res(); as a
result, the location of the name for the current reservation could
change.

Therefore, we need to save a local copy of the name.

[ hpa: rewrote comment and checkin description ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4B8C7C94.7070000@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---

diff --git a/kernel/early_res.c b/kernel/early_res.c
index 9ab11cd84853..3cb2c661bb78 100644
--- a/kernel/early_res.c
+++ b/kernel/early_res.c
@@ -79,9 +79,19 @@ static void __init drop_range_partial(int i, u64 start, u64 end)
 		/* make head segment */
 		early_res[i].end = common_start;
 		if (old_end > common_end) {
+			char name[15];
+
+			/*
+			 * Save a local copy of the name, since the
+			 * early_res array could get resized inside
+			 * reserve_early_without_check() ->
+			 * __check_and_double_early_res(), which would
+			 * make the current name pointer invalid.
+			 */
+			strncpy(name, early_res[i].name,
+					 sizeof(early_res[i].name) - 1);
 			/* add another for left over on tail */
-			reserve_early_without_check(common_end, old_end,
-					 early_res[i].name);
+			reserve_early_without_check(common_end, old_end, name);
 		}
 		return;
 	} else {