[Crash-utility] [PATCH V2] crash: arm32: a better way to identify LPAE enabled kernel

[Dave Anderson]

Hello Liu,

Your patch is queued for crash-7.0.9:

  https://github.com/crash-utility/crash/commit/8185107da80bb58d8af9ce37be292f3d46828117

Thanks,
  Dave


----- Original Message -----
> Thanks to Dave's suggest, I impove the way to identify
> LPAE enabled kernel for arm platform, for compatibility with
> some old kernel.
> 
> If a vmcore santisfy one of the following conditions, It must
> be generated by a LPAE enabled kernel.
> 
> (1) it has CONFIG_ARM_LPAE=y vmcore_info
> (2) swapper_pg_dir and its next symbol value differ by 0x5000
> 
> changes from V1:
>  - drop function next_symbol_value
> 
> Signed-off-by: Liu Hua <sdu.liu at huawei.com>
> ---
>  arm.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/arm.c b/arm.c
> index cb7d841..e7d3dbc 100644
> --- a/arm.c
> +++ b/arm.c
> @@ -190,6 +190,8 @@ void
>  arm_init(int when)
>  {
>  	ulong vaddr;
> +	char *string;
> +	struct syment *sp;
>  
>  #if defined(__i386__) || defined(__x86_64__)
>  	if (ACTIVE())
> @@ -229,8 +231,13 @@ arm_init(int when)
>  		 * LPAE requires an additional page for the PGD,
>  		 * so PG_DIR_SIZE = 0x5000 for LPAE
>  		 */
> -		if ((symbol_value("_text") - symbol_value("swapper_pg_dir")) == 0x5000)
> +		if ((string = pc->read_vmcoreinfo("CONFIG_ARM_LPAE"))) {
>  			machdep->flags |= PAE;
> +			free(string);
> +		} else if ((sp = next_symbol("swapper_pg_dir", NULL)) &&
> +		         (sp->value - symbol_value("swapper_pg_dir")) == 0x5000)
> +                         machdep->flags |= PAE;
> +
>  		machdep->kvbase = symbol_value("_stext") & ~KVBASE_MASK;
>  		machdep->identity_map_base = machdep->kvbase;
>  		machdep->is_kvaddr = arm_is_kvaddr;
> --
> 1.9.0
> 
>