於 日，2013-08-25 於 18:42 +0200，Pavel Machek 提到：

On Thu 2013-08-22 19:01:54, Lee, Chun-Yi wrote:

quoted

In current solution, the snapshot signature check used the RSA key-pair
that are generated by bootloader(e.g. shim) and pass the key-pair to
kernel through EFI variables. I choice to binding the snapshot
signature check mechanism with UEFI secure boot for provide stronger
protection of hibernate. Current behavior is following:

 + UEFI Secure Boot ON, Kernel found key-pair from shim:
   Will do the S4 signature check.

 + UEFI Secure Boot ON, Kernel didn't find key-pair from shim:
   Will lock down S4 function.

 + UEFI Secure Boot OFF
   Will NOT do the S4 signature check.
   Ignore any keys from bootloader.

v2:
Replace sign_key_data_loaded() by skey_data_available() to check sign key data
is available for hibernate.

Reviewed-by: Jiri Kosina <redacted>
Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
---
 kernel/power/hibernate.c |   36 +++++++++++++++++-
 kernel/power/main.c      |   11 +++++-
 kernel/power/snapshot.c  |   95 ++++++++++++++++++++++++++--------------------
 kernel/power/swap.c      |    4 +-
 kernel/power/user.c      |   11 +++++
 5 files changed, 112 insertions(+), 45 deletions(-)

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index c545b15..0f19f3d 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c

@@ -29,6 +29,7 @@
 #include <linux/ctype.h>
 #include <linux/genhd.h>
 #include <linux/key.h>
+#include <linux/efi.h>
 
 #include "power.h"
 

@@ -632,7 +633,14 @@ static void power_down(void)
 int hibernate(void)
 {
 	int error;
-	int skey_error;
+
+#ifdef CONFIG_SNAPSHOT_VERIFICATION
+	if (!capable(CAP_COMPROMISE_KERNEL) && !skey_data_available()) {
+#else
+	if (!capable(CAP_COMPROMISE_KERNEL)) {
+#endif
+		return -EPERM;
+	}
 
 	lock_system_sleep();
 	/* The snapshot device should not be opened while we're running */

@@ -799,6 +807,15 @@ static int software_resume(void)
 	if (error)
 		goto Unlock;
 
+#ifdef CONFIG_SNAPSHOT_VERIFICATION
+	if (!capable(CAP_COMPROMISE_KERNEL) && !wkey_data_available()) {
+#else
+	if (!capable(CAP_COMPROMISE_KERNEL)) {
+#endif
+		mutex_unlock(&pm_mutex);
+		return -EPERM;
+	}
+
 	/* The snapshot device should not be opened while we're running */
 	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 		error = -EBUSY;

@@ -892,6 +909,15 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 	int i;
 	char *start = buf;
 
+#ifdef CONFIG_SNAPSHOT_VERIFICATION
+	if (efi_enabled(EFI_SECURE_BOOT) && !skey_data_available()) {
+#else
+	if (efi_enabled(EFI_SECURE_BOOT)) {
+#endif
+		buf += sprintf(buf, "[%s]\n", "disabled");
+		return buf-start;
+	}
+
 	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 		if (!hibernation_modes[i])
 			continue;

@@ -926,6 +952,14 @@ static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
 	char *p;
 	int mode = HIBERNATION_INVALID;
 
+#ifdef CONFIG_SNAPSHOT_VERIFICATION
+	if (!capable(CAP_COMPROMISE_KERNEL) && !skey_data_available()) {
+#else
+	if (!capable(CAP_COMPROMISE_KERNEL)) {
+#endif
+		return -EPERM;
+	}
+
 	p = memchr(buf, '\n', n);
 	len = p ? p - buf : n;
 

You clearly need some helper function.
									Pavel

I will use a help function to replace those ifdef block.

Thanks for your suggestion!
Joey Lee