PM: Fix oops in suspend/hibernate code related to failing ioremap()

When ioremap() fails (which might happen for some reason), we nicely
oops in suspend_nvs_save() due to NULL dereference by memcpy() in there.
Fail gracefully instead.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

3 files changed, 11 insertions, 6 deletions

diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index febb153b5a68..d8bca6c90719 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -124,8 +124,7 @@ static int acpi_pm_freeze(void)
 static int acpi_pm_pre_suspend(void)
 {
         acpi_pm_freeze();
-        suspend_nvs_save();
-        return 0;
+        return suspend_nvs_save();
 }
 
 /**
@@ -151,7 +150,7 @@ static int acpi_pm_prepare(void)
 {
         int error = __acpi_pm_prepare();
         if (!error)
-                acpi_pm_pre_suspend();
+                error = acpi_pm_pre_suspend();
 
         return error;
 }
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 26697514c5ec..acb7d911bb0c 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -262,7 +262,7 @@ static inline bool system_entering_hibernation(void) { return false; }
 extern int suspend_nvs_register(unsigned long start, unsigned long size);
 extern int suspend_nvs_alloc(void);
 extern void suspend_nvs_free(void);
-extern void suspend_nvs_save(void);
+extern int suspend_nvs_save(void);
 extern void suspend_nvs_restore(void);
 #else /* CONFIG_SUSPEND_NVS */
 static inline int suspend_nvs_register(unsigned long a, unsigned long b)
@@ -271,7 +271,7 @@ static inline int suspend_nvs_register(unsigned long a, unsigned long b)
 }
 static inline int suspend_nvs_alloc(void) { return 0; }
 static inline void suspend_nvs_free(void) {}
-static inline void suspend_nvs_save(void) {}
+static inline int suspend_nvs_save(void) {}
 static inline void suspend_nvs_restore(void) {}
 #endif /* CONFIG_SUSPEND_NVS */
 
diff --git a/kernel/power/nvs.c b/kernel/power/nvs.c
index 1836db60bbb6..57c6fabbb6b6 100644
--- a/kernel/power/nvs.c
+++ b/kernel/power/nvs.c
@@ -105,7 +105,7 @@ int suspend_nvs_alloc(void)
 /**
  *      suspend_nvs_save - save NVS memory regions
  */
-void suspend_nvs_save(void)
+int suspend_nvs_save(void)
 {
         struct nvs_page *entry;
 
@@ -114,8 +114,14 @@ void suspend_nvs_save(void)
         list_for_each_entry(entry, &nvs_list, node)
                 if (entry->data) {
                         entry->kaddr = ioremap(entry->phys_start, entry->size);
+                        if (!entry->kaddr) {
+                                suspend_nvs_free();
+                                return -ENOMEM;
+                        }
                         memcpy(entry->data, entry->kaddr, entry->size);
                 }
+
+        return 0;
 }
 
 /**