[Crash-utility] [PATCH] Fix "sys [-t]|mod -S" after "mod -t" when crash runs with -s option

[lijiang]

Hi, Kazu
在 2021年01月21日 01:00, crash-utility-request at redhat.com 写道:
> Date: Wed, 20 Jan 2021 06:16:24 +0000
> From: HAGIO KAZUHITO(?????) 	<k-hagio-ab at nec.com>
> To: "crash-utility at redhat.com" <crash-utility at redhat.com>
> Subject: [Crash-utility] [PATCH] Fix "sys [-t]|mod -S" after "mod -t"
> 	when crash runs with -s option
> Message-ID:
> 	<OSBPR01MB199187BDE9E90C416DF2B327DDA20 at OSBPR01MB1991.jpnprd01.prod.outlook.com>
> 	
> Content-Type: text/plain; charset="iso-2022-jp"
> 
> When crash runs with -s option, SIZE(taint_flag) and OFFSET(tnt_false)
> are not set during initialization.  If the "mod -t" option is executed,
> it sets the former but does not set the latter.  After that, the "sys"
> command uses OFFSET(tnt_false) without setting it, because it checks
> only if SIZE(taint_flag) is set.
> 
> Without the patch, the "sys [-t]" and "mod -S" options after "mod -t"
> option fail with the error message:
> 
Hmm, I also ran into a similar issue with an old vmcore, that can be reproduced
with the following steps:

crash> history
[1] mod -S 3.10.0-957.el7.x86_64
[2] mod -s dm_service_time
[3] set scope st_create
[4] mod -d dm_service_time
[5] mod -sr dm_service_time
[6] set scope st_create
[7] sys
[8] set scope st_create

And after the step[7] "sys" command, the step[8] will definitely fail. But step[6]
is successful before the "sys" command.

Seems that it should be another issue.

Thanks.
Lianbo

>   sys: invalid structure member offset: tnt_false
>        FILE: kernel.c  LINE: 11203  FUNCTION: show_kernel_taints_v4_10()
> 
> Signed-off-by: Kazuhito Hagio <k-hagio-ab at nec.com>
> ---
>  kernel.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel.c b/kernel.c
> index 272e0d8751cf..5fcd86575be5 100644
> --- a/kernel.c
> +++ b/kernel.c
> @@ -11160,7 +11160,8 @@ show_kernel_taints_v4_10(char *buf, int verbose)
>  	ulong tainted_mask, *tainted_mask_ptr;
>  	struct syment *sp;
>  
> -	if (!VALID_STRUCT(taint_flag)) {
> +	if (!(VALID_STRUCT(taint_flag) &&
> +	     VALID_MEMBER(tnt_true) && VALID_MEMBER(tnt_false))) {
>  		STRUCT_SIZE_INIT(taint_flag, "taint_flag");
>  		MEMBER_OFFSET_INIT(tnt_true, "taint_flag", "true");
>  		MEMBER_OFFSET_INIT(tnt_false, "taint_flag", "false");
> -- 2.18.4