Well, fix up the Steven's address. On Thu, Mar 3, 2016 at 2:34 AM, Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote: > On Thu, Mar 3, 2016 at 1:43 AM, Todd Brandt > <todd.e.brandt@xxxxxxxxxxxxxxx> wrote: >> On Thu, 2016-03-03 at 01:19 +0100, Rafael J. Wysocki wrote: >>> On Thu, Mar 3, 2016 at 1:05 AM, Todd Brandt >>> <todd.e.brandt@xxxxxxxxxxxxxxx> wrote: >>> > 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@xxxxxxxxxxxxxxx> >>> >>> OK >>> >>> I guess we'll need that in -stable, right? >> >> Sure, it's pretty important. The new analyze_suspend features are going >> to rely pretty heavily on full graph trace of suspend (all we can do is >> standby and freeze now because of the bug). Thanks! > > OK, applied, but let Steven and the x86 folks see it. > >>> >>> > --- >>> > arch/x86/kernel/acpi/sleep.c | 7 +++++++ >>> > 1 file changed, 7 insertions(+) >>> > >>> > diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c >>> > index d1daead..311360e 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; >>> > } >>> > >>> > -- >>> > 2.1.4 >>> > >>> > -- > > > Thanks, > Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
