Hello,

On 9/30/2025 4:53 AM, lijiang wrote:
> On Tue, Sep 30, 2025 at 2:18 AM Mikhail Zaslonko <zaslonko@linux.ibm.com>
> wrote:
>
>> Hi Lianbo,
>>
>> It seems we have a problem printing disassembly blocks in the log after
>> this patch (at least on s390).
>> See number of empty lines printed below.
>>
>
> Can you try it with the following two patches?
> [1]
> https://www.mail-archive.com/devel@lists.crash-utility.osci.io/msg01621.html
This patch is present on crash master, doesnt affect the issue.
> [2]
> https://www.mail-archive.com/devel@lists.crash-utility.osci.io/msg01636.html
>
This one helps indeed! At least I do not se the blanks lines in my scenario.
BUT, if I use 'log -R' the blank lines are back again!

>
>> Before the patch:
>>   [   21.408784] Krnl GPRS: 000002aa3780c000 0000000000238c00
>> 0000000015800000 0000000000001000
>>   [   21.408787]            0000000008e30000 00000000b0001000
>> 0000000000000000 0000000000000a55
>>   [   21.408790]            0000000004c52300 000002aa3780c000
>> 00000000084281d0 0000038000bfbd28
>>   [   21.408794]            00000000075e9500 0000000004c52300
>> 0000038000bfbbf0 0000038000bfbb90
>>   [   21.408860] Krnl Code: 000000000e0acf48: c05fb0001000        llilf
>>  %r5,2952794112
>>                             000000000e0acf4e: ec4100b30659        risbgn
>> %r4,%r1,0,179,6
>>                            #000000000e0acf54: 0e24                mvcl
>> %r2,%r4
>>                            >000000000e0acf56: a7280000            lhi
>>  %r2,0
>>                             000000000e0acf5a: eb6ff0a80004        lmg
>>  %r6,%r15,168(%r15)
>>                             000000000e0acf60: b9140022            lgfr
>> %r2,%r2
>>                             000000000e0acf64: 07fe                bcr
>>  15,%r14
>>                             000000000e0acf66: 47000700            bc
>> 0,1792
>>   [   21.408883] Call Trace:
>>
>> After the patch:
>>   [   21.408784] Krnl GPRS: 000002aa3780c000 0000000000238c00
>> 0000000015800000 0000000000001000
>>   [   21.408787]            0000000008e30000 00000000b0001000
>> 0000000000000000 0000000000000a55
>>   [   21.408790]            0000000004c52300 000002aa3780c000
>> 00000000084281d0 0000038000bfbd28
>>   [   21.408794]            00000000075e9500 0000000004c52300
>> 0000038000bfbbf0 0000038000bfbb90
>>   [   21.408860]
>>
>>
>>
>>
>>
>>
>>                  Krnl Code: 000000000e0acf48: c05fb0001000        llilf
>>  %r5,2952794112
>>   [   21.408883] Call Trace:
>>
>> I think your approach of storing printable characters in the buffer with
>> the intention to modify it
>> afterwards (see [1] below) instead of writing it character wise does not
>> work when the input data
>> contains several lines. Those '\n' are written one by one, what leads to
>> the result shown above.
>> You should probably buffer and 'demangle' each line separately.
>>
>
> Looks like different issues.  Can you share your vmcore and vmlinux with
> me? I did not reproduce it.


>
> Thanks
> Lianbo
>
>>
>>
>