Messages in this thread Patch in this message | | | From | Thomas Garnier <> | Subject | [PATCH v1 2/2] x86/power/64: Fix __PAGE_OFFSET usage on restore | Date | Mon, 1 Aug 2016 10:08:00 -0700 |
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When KASLR memory randomization is used, __PAGE_OFFSET is a global variable changed during boot. The assembly code was using the variable as an immediate value to calculate the cr3 physical address. The physical address was incorrect resulting to a GP fault.
Signed-off-by: Thomas Garnier <thgarnie@google.com> --- arch/x86/power/hibernate_asm_64.S | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/x86/power/hibernate_asm_64.S b/arch/x86/power/hibernate_asm_64.S index 8eee0e9..8db4905 100644 --- a/arch/x86/power/hibernate_asm_64.S +++ b/arch/x86/power/hibernate_asm_64.S @@ -23,6 +23,16 @@ #include <asm/processor-flags.h> #include <asm/frame.h> +/* + * A global variable holds the page_offset when KASLR memory randomization + * is enabled. + */ +#ifdef CONFIG_RANDOMIZE_MEMORY +#define __PAGE_OFFSET_REF __PAGE_OFFSET +#else +#define __PAGE_OFFSET_REF $__PAGE_OFFSET +#endif + ENTRY(swsusp_arch_suspend) movq $saved_context, %rax movq %rsp, pt_regs_sp(%rax) @@ -72,7 +82,7 @@ ENTRY(restore_image) /* code below has been relocated to a safe page */ ENTRY(core_restore_code) /* switch to temporary page tables */ - movq $__PAGE_OFFSET, %rcx + movq __PAGE_OFFSET_REF, %rcx subq %rcx, %rax movq %rax, %cr3 /* flush TLB */ -- 2.8.0.rc3.226.g39d4020
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