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authorTodd E Brandt <todd.e.brandt@linux.intel.com>2016-03-02 16:05:29 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-03-09 15:34:52 -0800
commitaf2d87aeac4fac50bcb5e0cf5a7d37edc72fed1f (patch)
treeac7047f4ac930354c5e7667e577e886e5f92a4ce /arch
parente75c4b65150f099789821cb5e3f0efc964c1db05 (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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-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 d1daead5fcdd..adb3eaf8fe2a 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"
@@ -107,7 +108,13 @@ 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;
}