[Crash-utility] [PATCH] raw_data_dump: display only 8/16/32 bits if requested

[Dave Anderson]

----- Original Message -----
> Previously, calling raw_data_dump() with e.g. len 4 on 64bit systems
> would dump 8 bytes anyway, making it hard to tell what one wants to see.
> 
> For example, with task_struct.rt_priority a uint32.
> before patch:
> crash> struct -r task_struct.rt_priority ffff8d9b36186180
> ffff8d9b361861dc:  9741dec000000063                    c.....A.
> 
> after patch:
> crash-patched> struct -r task_struct.rt_priority ffff8d9b36186180
> ffff8d9b361861dc:  00000063                              c...
> ---
> 
> Here's the promised follow-up.
> 
> Two remarks:
>  - I wasn't sure about an explicit DISPLAY_64 flag, but if we're 32bit
> and want to print 8 bytes it is just as likely to be two entities than
> a single one so it makes more sense to leave default to me.
>  - I wasn't sure on what to do if someone wants to print some odd size,
> e.g. 6 bits? Should that be DISPLAY_8 anyway?
> I tried on some bitmap and it looks like raw_data_dump is called with 8
> anyway even if the bitmap part is less than 8, I'm not sure this can
> ever be called with weird values, so probably best left as is.

Yes, let's do that -- queued for crash-7.2.9:

  https://github.com/crash-utility/crash/commit/8c28b5625505241d80ec5162f58ccc563e5e59f9

Thanks,
  Dave



> Thanks!
> 
>  memory.c | 19 ++++++++++++++++++-
>  1 file changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/memory.c b/memory.c
> index 4f7b6a0..ccc2944 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -2113,6 +2113,7 @@ raw_data_dump(ulong addr, long count, int symbolic)
>  	long wordcnt;
>  	ulonglong address;
>  	int memtype;
> +	ulong flags = HEXADECIMAL;
>  
>  	switch (sizeof(long))
>  	{
> @@ -2132,6 +2133,22 @@ raw_data_dump(ulong addr, long count, int symbolic)
>  		break;
>  	}
>  
> +	switch (count)
> +	{
> +	case SIZEOF_8BIT:
> +		flags |= DISPLAY_8;
> +		break;
> +	case SIZEOF_16BIT:
> +		flags |= DISPLAY_16;
> +		break;
> +	case SIZEOF_32BIT:
> +		flags |= DISPLAY_32;
> +		break;
> +	default:
> +		flags |= DISPLAY_DEFAULT;
> +		break;
> +	}
> +
>  	if (pc->curcmd_flags & MEMTYPE_FILEADDR) {
>  		address = pc->curcmd_private;
>  		memtype = FILEADDR;
> @@ -2144,7 +2161,7 @@ raw_data_dump(ulong addr, long count, int symbolic)
>  	}
>  
>  	display_memory(address, wordcnt,
> - 	    HEXADECIMAL|DISPLAY_DEFAULT|(symbolic ? SYMBOLIC : ASCII_ENDLINE),
> +		flags|(symbolic ? SYMBOLIC : ASCII_ENDLINE),
>  		memtype, NULL);
>  }
>  
> --
> 2.26.0
> 
> 
> --
> Crash-utility mailing list
> Crash-utility at redhat.com
> https://www.redhat.com/mailman/listinfo/crash-utility
>