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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 15:31:54 -0800
commit137d2a237dc2f38bd8623c03e95279643330e878 (patch)
tree67f1cd67307453bf81a92dfc8d168f92ce745b15
parentf105a72e6e71244643bc0a5dc44bfab1fe3d76f9 (diff)
downloadlinux-linaro-stable-137d2a237dc2f38bd8623c03e95279643330e878.tar.gz
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>
-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 ec94e11807dc..ca0805633f26 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 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;
}