Re: [PATCH] btrace: kernel address filtering

[Pedro Alves <palves@redhat.com>]

On 09/01/2015 04:42 PM, Markus Metzger wrote:

> --- a/gdb/nat/linux-btrace.h
> +++ b/gdb/nat/linux-btrace.h
> @@ -101,10 +101,11 @@ struct btrace_target_info
>    } variant;
>  #endif /* HAVE_LINUX_PERF_EVENT_H */
>  
> -  /* The size of a pointer in bits for this thread.
> -     The information is used to identify kernel addresses in order to skip
> -     records from/to kernel space.  */
> -  int ptr_bits;
> +  /* The kernel start address.
> +     The information is used to tell kernel addresses from user addresses in
> +     order to skip records from kernel space.  We assume that any address
> +     smaller than KERNEL_START is in user space.  */
> +  uint64_t kernel_start;

Is there a reason we need to store the kernel's start address on every thread?

Thanks,
Pedro Alves