Re: [PATCH v4 11/27] x86/power/64: Adapt assembly for PIE support

From: Rafael J. Wysocki
Date: Wed May 30 2018 - 04:20:23 EST


On Wed, May 30, 2018 at 12:15 AM, Thomas Garnier <thgarnie@xxxxxxxxxx> wrote:
> Change the assembly code to use only relative references of symbols for the
> kernel to be PIE compatible.
>
> Position Independent Executable (PIE) support will allow to extend the
> KASLR randomization range 0xffffffff80000000.
>
> Signed-off-by: Thomas Garnier <thgarnie@xxxxxxxxxx>
> Acked-by: Pavel Machek <pavel@xxxxxx>

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

> ---
> arch/x86/power/hibernate_asm_64.S | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/power/hibernate_asm_64.S b/arch/x86/power/hibernate_asm_64.S
> index ce8da3a0412c..6fdd7bbc3c33 100644
> --- a/arch/x86/power/hibernate_asm_64.S
> +++ b/arch/x86/power/hibernate_asm_64.S
> @@ -24,7 +24,7 @@
> #include <asm/frame.h>
>
> ENTRY(swsusp_arch_suspend)
> - movq $saved_context, %rax
> + leaq saved_context(%rip), %rax
> movq %rsp, pt_regs_sp(%rax)
> movq %rbp, pt_regs_bp(%rax)
> movq %rsi, pt_regs_si(%rax)
> @@ -115,7 +115,7 @@ ENTRY(restore_registers)
> movq %rax, %cr4; # turn PGE back on
>
> /* We don't restore %rax, it must be 0 anyway */
> - movq $saved_context, %rax
> + leaq saved_context(%rip), %rax
> movq pt_regs_sp(%rax), %rsp
> movq pt_regs_bp(%rax), %rbp
> movq pt_regs_si(%rax), %rsi
> --
> 2.17.0.921.gf22659ad46-goog
>