[Crash-utility] Re: [PATCH v2 3/3] Enable resolving mangled Rust symbol in lockless ring buffer

On Tue, Sep 30, 2025 at 8:18 PM lijiang <lijiang(a)redhat.com&gt; wrote: > > On Tue, Sep 30, 2025 at 3:01 PM Mikhail Zaslonko <zaslonko(a)linux.ibm.com&gt; wrote: >> >> Hello, >> >> On 9/30/2025 4:53 AM, lijiang wrote: >>> On Tue, Sep 30, 2025 at 2:18 AM Mikhail Zaslonko <zaslonko(a)linux.ibm.com&gt; >>> 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! > > > Thanks for the information, Mikhail. > Let me see how to debug this(although I can not reproduce it on s390x). I didn't reproduce the issue on my s390x machine either, maybe sharing the vmcore to us can help.

Thanks, Tao Liu > > Thanks > Lianbo > >> >> >>> >>>> 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 >>> >>>> >>>> >>> >>