lkml.org 
[lkml]   [2017]   [Dec]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] Fix resume on x86-32 machines
From
Date


> On Dec 10, 2017, at 1:38 PM, Pavel Machek <pavel@ucw.cz> wrote:
>
>
> After 4.15-rc2, suspend stopped working on Thinkpad X60. 5b06bbc
> (unintentionally?) reordered stuff with respect to
> fix_processor_context() on 32-bit and 64-bit. We undo that change on
> 32-bit.
>

Can you explain what was wrong with the reordering? Your patch certainly *looks* incorrect.

I'm guessing that the real issue is that 32-bit needs %fs restored early for TLS.

> While we are at it, fix a comment.
>
> Signed-off-by: Pavel Machek <pavel@ucw.cz>
> Fixes: 5b06bbcfc2c621da3009da8decb7511500c293ed
>
> diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
> index 5191de1..af7b613 100644
> --- a/arch/x86/power/cpu.c
> +++ b/arch/x86/power/cpu.c
> @@ -216,8 +216,8 @@ static void notrace __restore_processor_state(struct saved_context *ctxt)
> write_cr0(ctxt->cr0);
>
> /*
> - * now restore the descriptor tables to their proper values
> - * ltr is done i fix_processor_context().
> + * Now restore the descriptor tables to their proper values
> + * ltr is done in fix_processor_context().
> */
> #ifdef CONFIG_X86_32
> load_idt(&ctxt->idt);
> @@ -235,13 +235,11 @@ static void notrace __restore_processor_state(struct saved_context *ctxt)
> wrmsrl(MSR_GS_BASE, ctxt->gs_base);
> #endif
>
> - fix_processor_context();
> -
> +#ifdef CONFIG_X86_32
> /*
> - * Restore segment registers. This happens after restoring the GDT
> - * and LDT, which happen in fix_processor_context().
> + * Restore segment registers.
> */
> -#ifdef CONFIG_X86_32
> +
> loadsegment(es, ctxt->es);
> loadsegment(fs, ctxt->fs);
> loadsegment(gs, ctxt->gs);
> @@ -252,8 +250,17 @@ static void notrace __restore_processor_state(struct saved_context *ctxt)
> */
> if (boot_cpu_has(X86_FEATURE_SEP))
> enable_sep_cpu();
> +
> + fix_processor_context();
> #else
> /* CONFIG_X86_64 */
> + /*
> + * Restore segment registers. This happens after restoring the GDT
> + * and LDT, which happen in fix_processor_context().
> + */
> +
> + fix_processor_context();
> +
> asm volatile ("movw %0, %%ds" :: "r" (ctxt->ds));
> asm volatile ("movw %0, %%es" :: "r" (ctxt->es));
> asm volatile ("movw %0, %%fs" :: "r" (ctxt->fs));
>
>
> --
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

\
 
 \ /
  Last update: 2017-12-10 22:59    [W:0.149 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site