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authorThomas Garnier <thgarnie@google.com>2016-08-11 14:49:29 -0700
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-08-12 22:50:42 +0200
commit62822e2ec4ad091ba31f823f577ef80db52e3c2c (patch)
tree5ad5beabd2c6d46e8949f32d1c359b094c12ba94
parente4630fdd47637168927905983205d7b7c5c08c09 (diff)
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PM / hibernate: Restore processor state before using per-CPU variables
Restore the processor state before calling any other functions to ensure per-CPU variables can be used with KASLR memory randomization. Tracing functions use per-CPU variables (GS based on x86) and one was called just before restoring the processor state fully. It resulted in a double fault when both the tracing & the exception handler functions tried to use a per-CPU variable. Fixes: bb3632c6101b (PM / sleep: trace events for suspend/resume) Reported-and-tested-by: Borislav Petkov <bp@suse.de> Reported-by: Jiri Kosina <jikos@kernel.org> Tested-by: Rafael J. Wysocki <rafael@kernel.org> Tested-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Thomas Garnier <thgarnie@google.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--kernel/power/hibernate.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 0ee1df0a0bd6..61761aa7cc19 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -300,12 +300,12 @@ static int create_image(int platform_mode)
save_processor_state();
trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
error = swsusp_arch_suspend();
+ /* Restore control flow magically appears here */
+ restore_processor_state();
trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
if (error)
printk(KERN_ERR "PM: Error %d creating hibernation image\n",
error);
- /* Restore control flow magically appears here */
- restore_processor_state();
if (!in_suspend)
events_check_enabled = false;