> Restore ftrace after jumping back from kexeced kernel.
>
> Signed-off-by: Huang Ying <ying.huang at intel.com>
>
> ---
> arch/x86/kernel/machine_kexec_32.c | 19 +++++++++++++++++++
> kernel/kexec.c | 2 --
> 2 files changed, 19 insertions(+), 2 deletions(-)
>
> @@ -124,7 +126,15 @@ void machine_kexec(struct kimage *image)
> unsigned int has_pae,
> unsigned int preserve_context);
>
> +#ifdef CONFIG_KEXEC_JUMP
> + if (kexec_image->preserve_context)
> + save_processor_state();
> +#endif
> +
> +#ifdef CONFIG_FTRACE
> + save_ftrace_enabled = ftrace_enabled;
> tracer_disable();
> +#endif
>
> /* Interrupts aren't acceptable while we reboot */
> raw_local_irq_disable();
The patch does way more than its changelog says...
Pavel
> @@ -182,6 +192,15 @@ void machine_kexec(struct kimage *image)
> (unsigned long)page_list,
> image->start, cpu_has_pae,
> image->preserve_context);
> +
> +#ifdef CONFIG_KEXEC_JUMP
> + if (kexec_image->preserve_context)
> + restore_processor_state();
> +#endif
> +
> +#ifdef CONFIG_FTRACE
> + ftrace_enabled = save_ftrace_enabled;
> +#endif
> }
>
> void arch_crash_save_vmcoreinfo(void)
> --- a/kernel/kexec.c
> +++ b/kernel/kexec.c
> @@ -1469,7 +1469,6 @@ int kernel_kexec(void)
> error = device_power_down(PMSG_FREEZE);
> if (error)
> goto Enable_irqs;
> - save_processor_state();
> } else
> #endif
> {
> @@ -1482,7 +1481,6 @@ int kernel_kexec(void)
>
> #ifdef CONFIG_KEXEC_JUMP
> if (kexec_image->preserve_context) {
> - restore_processor_state();
> device_power_up(PMSG_RESTORE);
> Enable_irqs:
> local_irq_enable();
>
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html