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authorTodd E Brandt <todd.e.brandt@linux.intel.com>2016-03-02 16:05:29 -0800
committerJiri Slaby <jslaby@suse.cz>2016-03-07 16:05:24 +0100
commit7dabf7e04ad03585ddfa7bc9d5e982ab79521a02 (patch)
tree11ba66a4872ca91420308877bd5aaee52268f416
parent54709aebcea1709772a302a9592d52a8252bc08d (diff)
PM / sleep / x86: Fix crash on graph trace through x86 suspend
commit 92f9e179a702a6adbc11e2fedc76ecd6ffc9e3f7 upstream. Pause/unpause graph tracing around do_suspend_lowlevel as it has inconsistent call/return info after it jumps to the wakeup vector. The graph trace buffer will otherwise become misaligned and may eventually crash and hang on suspend. To reproduce the issue and test the fix: Run a function_graph trace over suspend/resume and set the graph function to suspend_devices_and_enter. This consistently hangs the system without this fix. Signed-off-by: Todd Brandt <todd.e.brandt@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
-rw-r--r--arch/x86/kernel/acpi/sleep.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index 33120100ff5e..06bd995071de 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -16,6 +16,7 @@
#include <asm/cacheflush.h>
#include <asm/realmode.h>
+#include <linux/ftrace.h>
#include "../../realmode/rm/wakeup.h"
#include "sleep.h"
@@ -96,7 +97,13 @@ int x86_acpi_suspend_lowlevel(void)
saved_magic = 0x123456789abcdef0L;
#endif /* CONFIG_64BIT */
+ /*
+ * Pause/unpause graph tracing around do_suspend_lowlevel as it has
+ * inconsistent call/return info after it jumps to the wakeup vector.
+ */
+ pause_graph_tracing();
do_suspend_lowlevel();
+ unpause_graph_tracing();
return 0;
}