Re: [PATCH v2] x86, kaslr: propagate base load address calculation

Borislav Petkov
2015-02-17T22:31:57Z

On Tue, Feb 17, 2015 at 08:45:53AM -0800, Kees Cook wrote:
> Maybe it should say:
>
> Kernel offset: disabled
>
> for maximum clarity?

I.e.:

---
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 78c91bbf50e2..16b6043cb073 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -843,10 +843,14 @@ static void __init trim_low_memory_range(void)
static int
dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
{
- pr_emerg("Kernel Offset: 0x%lx from 0x%lx "
- "(relocation range: 0x%lx-0x%lx)\n",
- (unsigned long)&_text - __START_KERNEL, __START_KERNEL,
- __START_KERNEL_map, MODULES_VADDR-1);
+ if (kaslr_enabled)
+ pr_emerg("Kernel Offset: 0x%lx from 0x%lx (relocation range: 0x%lx-0x%lx)\n",
+ (unsigned long)&_text - __START_KERNEL,
+ __START_KERNEL,
+ __START_KERNEL_map,
+ MODULES_VADDR-1);
+ else
+ pr_emerg("Kernel Offset: disabled\n");

return 0;
}
---

?

--
Regards/Gruss,
Boris.

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