Re: [PATCH v2] x86, kaslr: export offset in VMCOREINFO ELF notes

[Adrian Hunter <adrian.hunter@intel.com>]

On 25/01/14 09:47, Ingo Molnar wrote:
> 
> * Kees Cook <keescook@chromium.org> wrote:
> 
>> From: Eugene Surovegin <surovegin@google.com>
>>
>> Include kASLR offset in VMCOREINFO ELF notes to assist in debugging.
>>
>> Signed-off-by: Eugene Surovegin <surovegin@google.com>
>> Signed-off-by: Kees Cook <keescook@chromium.org>
>> ---
>> v2:
>>  - make sure "From:" got sent correctly
>> ---
>>  arch/x86/kernel/machine_kexec_64.c |    2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
>> index 4eabc160696f..679cef0791cd 100644
>> --- a/arch/x86/kernel/machine_kexec_64.c
>> +++ b/arch/x86/kernel/machine_kexec_64.c
>> @@ -279,5 +279,7 @@ void arch_crash_save_vmcoreinfo(void)
>>  	VMCOREINFO_SYMBOL(node_data);
>>  	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
>>  #endif
>> +	vmcoreinfo_append_str("KERNELOFFSET=%lx\n",
>> +			      (unsigned long)&_text - __START_KERNEL);
>>  }
> 
> I've Cc:-ed Adrian Hunter, who has sent the following kaslr fixes for 
> perf yesterday:
> 
>   http://lkml.org/lkml/2014/1/24/220
> 
> Adrian, is this patch the right solution from the perf tooling 
> perspective?

perf tools isn't a consumer of VMCOREINFO although I see VMCOREINFO already
has _stext which would be enough for many purposes.

> 
> Thanks,
> 
> 	Ingo
> 
>