44 lines
1.2 KiB
Diff
44 lines
1.2 KiB
Diff
|
From 673ff3585880ccacc53abaea01df027859ed5c1b Mon Sep 17 00:00:00 2001
|
||
|
|
From: root <root@localhost.localdomain>
|
||
|
|
Date: Wed, 13 Mar 2019 14:44:36 +0800
|
||
|
|
Subject: [PATCH 14/17] libdm: add memory barrier
|
||
|
|
|
||
|
|
Just for case ensure compiler is not able to optimize
|
||
|
|
memset() away for resources that are released.
|
||
|
|
|
||
|
|
This idea of using memory barrier is taken from openssl.
|
||
|
|
|
||
|
|
Other options would be to check for 'explicit_bzero' function.
|
||
|
|
|
||
|
|
(cherry picked from commit 55a8d6c86b4c6c6c707cfcc3dd887bca0632114f)
|
||
|
|
|
||
|
|
Conflicts:
|
||
|
|
device_mapper/ioctl/libdm-iface.c
|
||
|
|
---
|
||
|
|
libdm/ioctl/libdm-iface.c | 2 ++
|
||
|
|
1 file changed, 2 insertions(+)
|
||
|
|
|
||
|
|
diff --git a/libdm/ioctl/libdm-iface.c b/libdm/ioctl/libdm-iface.c
|
||
|
|
index 769b69c..7f48e37 100644
|
||
|
|
--- a/libdm/ioctl/libdm-iface.c
|
||
|
|
+++ b/libdm/ioctl/libdm-iface.c
|
||
|
|
@@ -466,6 +466,7 @@ static void _dm_zfree_string(char *string)
|
||
|
|
{
|
||
|
|
if (string) {
|
||
|
|
memset(string, 0, strlen(string));
|
||
|
|
+ asm volatile ("" ::: "memory"); /* Compiler barrier. */
|
||
|
|
dm_free(string);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
@@ -474,6 +475,7 @@ static void _dm_zfree_dmi(struct dm_ioctl *dmi)
|
||
|
|
{
|
||
|
|
if (dmi) {
|
||
|
|
memset(dmi, 0, dmi->data_size);
|
||
|
|
+ asm volatile ("" ::: "memory"); /* Compiler barrier. */
|
||
|
|
dm_free(dmi);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
--
|
||
|
|
2.19.1
|
||
|
|
|