Re: -tip tree resume fail, bisect to 5bd5a45(x86: Add NXprotection for kernel data)

From: Lin Ming
Date: Tue Nov 30 2010 - 19:12:48 EST


On Tue, 2010-11-30 at 19:27 +0800, Peter Zijlstra wrote:
> On Tue, 2010-11-30 at 13:00 +0800, Lin Ming wrote:
> > echo 0 > /sys/devices/system/cpu/cpu1/online;
> > echo 1 > /sys/devices/system/cpu/cpu1/online;
> >
> > then machine just reboots...
> >
>
> That should work on current -tip (and my test machine confirms with a
> -tip of yesterday) due to:

Yes, I know.

I tested for Mat's request to confirm that CPU suspend/resume also
broken, not only S3.

And no interesting trace I can get because machine just reboots
immediately when CPU suspend/resume.

Thanks.

>
> ---
> commit 691513f70d3957939a318da970987b876c720861
> Author: Lin Ming <ming.m.lin@xxxxxxxxx>
> Date: Mon Nov 22 14:03:28 2010 +0100
>
> x86: Resume trampoline must be executable
>
> commit 5bd5a452(x86: Add NX protection for kernel data) marked the
> trampoline area NX - which unsurprisingly breaks resume and cpu
> hotplug.
>
> Revert the portion of that commit, which touches the trampoline.
>
> Originally-from: Lin Ming <ming.m.lin@xxxxxxxxx>
> LKML-Reference: <1290410581.2405.24.camel@xxxxxxxxxxxxxxxxxxx>
> Cc: Matthieu Castet <castet.matthieu@xxxxxxx>
> Cc: Siarhei Liakh <sliakh.lkml@xxxxxxxxx>
> Cc: Xuxian Jiang <jiang@xxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxx>
> Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxx>
> Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
> Tested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>
> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
> index ce59c05..71a5929 100644
> --- a/arch/x86/mm/init_64.c
> +++ b/arch/x86/mm/init_64.c
> @@ -788,7 +788,6 @@ void mark_rodata_ro(void)
> unsigned long rodata_start =
> ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
> unsigned long end = (unsigned long) &__end_rodata_hpage_align;
> - unsigned long kernel_end = (((unsigned long)&__init_end + HPAGE_SIZE) & HPAGE_MASK);
> unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table);
> unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata);
> unsigned long data_start = (unsigned long) &_sdata;
> @@ -803,7 +802,7 @@ void mark_rodata_ro(void)
> * The rodata section (but not the kernel text!) should also be
> * not-executable.
> */
> - set_memory_nx(rodata_start, (kernel_end - rodata_start) >> PAGE_SHIFT);
> + set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
>
> rodata_test();
>
>


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