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/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 6eaa9cd..f8f0466 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2184,6 +2184,8 @@
in certain environments such as networked servers or
real-time systems.
+ nohibernate [HIBERNATION] Disable hibernation and resume.
+
nohz= [KNL] Boottime enable/disable dynamic ticks
Valid arguments: on, off
Default: on
@@ -2980,6 +2982,7 @@
noresume Don't check if there's a hibernation image
present during boot.
nocompress Don't compress/decompress hibernation images.
+ no Disable hibernation and resume.
retain_initrd [RAM] Keep initrd memory after extraction
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index f76994b..519064e 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -327,6 +327,7 @@
extern void hibernation_set_ops(const struct platform_hibernation_ops *ops);
extern int hibernate(void);
extern bool system_entering_hibernation(void);
+extern bool hibernation_available(void);
asmlinkage int swsusp_save(void);
extern struct pbe *restore_pblist;
#else /* CONFIG_HIBERNATION */
@@ -339,6 +340,7 @@
static inline void hibernation_set_ops(const struct platform_hibernation_ops *ops) {}
static inline int hibernate(void) { return -ENOSYS; }
static inline bool system_entering_hibernation(void) { return false; }
+static inline bool hibernation_available(void) { return false; }
#endif /* CONFIG_HIBERNATION */
/* Hibernation and suspend events */
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);
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 573410d..8e90f33 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -300,13 +300,11 @@
s += sprintf(s,"%s ", pm_states[i].label);
#endif
-#ifdef CONFIG_HIBERNATION
- s += sprintf(s, "%s\n", "disk");
-#else
+ if (hibernation_available())
+ s += sprintf(s, "disk ");
if (s != buf)
/* convert the last space to a newline */
*(s-1) = '\n';
-#endif
return (s - buf);
}
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 98d35758..526e891 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -49,6 +49,9 @@
struct snapshot_data *data;
int error;
+ if (!hibernation_available())
+ return -EPERM;
+
lock_system_sleep();
if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {