2018-05-29 22:24:49

by Thomas Garnier

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

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 <[email protected]>
Acked-by: Pavel Machek <[email protected]>
---
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

2018-05-30 08:21:34

by Rafael J. Wysocki

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

On Wed, May 30, 2018 at 12:15 AM, Thomas Garnier <[email protected]> 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 <[email protected]>
> Acked-by: Pavel Machek <[email protected]>

Acked-by: Rafael J. Wysocki <[email protected]>

> ---
> 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
>