PM / hibernate: introduce "nohibernate" boot parameter
To support using kernel features that are not compatible with hibernation,
this creates the "nohibernate" kernel boot parameter to disable both
hibernation and resume. This allows hibernation support to be a boot-time
choice instead of only a compile-time choice.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 49e0a20..258f492 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -35,6 +35,7 @@
static int nocompress;
static int noresume;
+static int nohibernate;
static int resume_wait;
static unsigned int resume_delay;
static char resume_file[256] = CONFIG_PM_STD_PARTITION;
@@ -62,6 +63,11 @@
static const struct platform_hibernation_ops *hibernation_ops;
+bool hibernation_available(void)
+{
+ return (nohibernate == 0);
+}
+
/**
* hibernation_set_ops - Set the global hibernate operations.
* @ops: Hibernation operations to use in subsequent hibernation transitions.
@@ -642,6 +648,11 @@
{
int error;
+ if (!hibernation_available()) {
+ pr_debug("PM: Hibernation not available.\n");
+ return -EPERM;
+ }
+
lock_system_sleep();
/* The snapshot device should not be opened while we're running */
if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
@@ -734,7 +745,7 @@
/*
* If the user said "noresume".. bail out early.
*/
- if (noresume)
+ if (noresume || !hibernation_available())
return 0;
/*
@@ -900,6 +911,9 @@
int i;
char *start = buf;
+ if (!hibernation_available())
+ return sprintf(buf, "[disabled]\n");
+
for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
if (!hibernation_modes[i])
continue;
@@ -934,6 +948,9 @@
char *p;
int mode = HIBERNATION_INVALID;
+ if (!hibernation_available())
+ return -EPERM;
+
p = memchr(buf, '\n', n);
len = p ? p - buf : n;
@@ -1101,6 +1118,10 @@
noresume = 1;
else if (!strncmp(str, "nocompress", 10))
nocompress = 1;
+ else if (!strncmp(str, "no", 2)) {
+ noresume = 1;
+ nohibernate = 1;
+ }
return 1;
}
@@ -1125,9 +1146,17 @@
return 1;
}
+static int __init nohibernate_setup(char *str)
+{
+ noresume = 1;
+ nohibernate = 1;
+ return 1;
+}
+
__setup("noresume", noresume_setup);
__setup("resume_offset=", resume_offset_setup);
__setup("resume=", resume_setup);
__setup("hibernate=", hibernate_setup);
__setup("resumewait", resumewait_setup);
__setup("resumedelay=", resumedelay_setup);
+__setup("nohibernate", nohibernate_setup);