Perf + Opencsd (aarch64) Off Target Trace Decoding shows "could not read first record/send request"

[Suzuki K Poulose]

On 11/07/2023 10:26, Pandey, Radhey Shyam wrote:
> Hi all,
> 
> I am trying off Target Trace Decoding using arm-cs-trace-disasm.py but 
> it doesn’t show
> 
> proper disassembly. There is unexpected warning "could not read first 
> record".


> 
> Any pointers on what the issue could be?
> 
> Meanwhile I am trying to do trace decoding on aarch64 target and see if 
> that helps.
> 
> I have taken simple example mentioned in [1].
> 
> [1]: 
> http://events17.linuxfoundation.org/sites/events/files/slides/ELC-E16.pdf <http://events17.linuxfoundation.org/sites/events/files/slides/ELC-E16.pdf>
> 
> #include int coresight_test1(int val);
> 
> int main(void) {
> 
> int val; val = coresight_test1(10);
> 
> printf("val: %d\n", val);
> 
> return 0;
> 
> }
> 
> perf record -e cs_etm/@tmc_etf0/u --filter 
> 'filter0x5a8/0x5e4@/home/root/libcstest.so.1.0' --per-thread ./main
> 
> tar czf cs_example.tgz perf.data ~/.debug
> 
> Off Target Trace Decoding: “perf report”
> 
> tar xf cs_example.tgz
> 
> $ rm -rf ~/.debug // remove previous trace data
> 
> $ cp -dpR .debug ~/ // copy the current trace data
> 
> $ perf report --stdio
> 
> linux-xlnx/tools/perf/perf --exec-path= <snip>/linux-xlnx/tools/perf 
> script tools/perf/scripts/python/arm-cs-trace-disasm.py -- -d 
> ${XTOOL_PATH}/aarch64-linux-gnu-objdump -v
> 

I believe the perf script doesn't work with coresight trace decoding
as we need a two pass approach for decoding the stream for figuring out
the parameters for the queues. James Clark can give you the exact reason.

Suzuki




> ARM CoreSight Trace Data Assembler Dump
> 
> addr2line /home/root/libcstest.so.1.0: could not read first record
> 
>              main   748/748   [0000]         0.000000000      
> ffffad8c05d8                         /home/root/libcstest.so.1.0
> 
> addr2line /home/root/libcstest.so.1.0: could not send request
> 
>              main   748/748   [0000]         0.000000000      ffffad8c05d8
> 
> addr2line /home/root/libcstest.so.1.0: could not send request
> 
>              main   748/748   [0000]         0.000000000      ffffad8c05d8
> 
> addr2line /home/root/libcstest.so.1.0: could not send request
> 
>              main   748/748   [0000]         0.000000000      ffffad8c05d8
> 
> addr2line /home/root/libcstest.so.1.0: could not send request
> 
>              main   748/748   [0000]         0.000000000      ffffad8c05d8
> 
> addr2line /home/root/libcstest.so.1.0: could not send request
> 
>              main   748/748   [0000]         0.000000000      ffffad8c05e4
> 
> End
> 
> tools/perf/perf report -D
> 
> <snip>
> 
> 0x680 [0x30]: PERF_RECORD_AUXTRACE size: 0x90  offset: 0  ref: 
> 0x2890bdbd7cad6b6f  idx: 0  tid: 748  cpu: -1
> 
> . ... CoreSight ETMV4I Trace data: size 0x20 bytes
> 
>          Idx:0; ID:10;   I_ASYNC : Alignment Synchronisation.
> 
>          Idx:12; ID:10;  I_TRACE_INFO : Trace Info.; INFO=0x0 { CC.0 }
> 
> . ... CoreSight ETMV4I Trace data: size 0x20 bytes
> 
>          Idx:32; ID:10;  I_ASYNC : Alignment Synchronisation.
> 
>          Idx:44; ID:10;  I_TRACE_INFO : Trace Info.; INFO=0x0 { CC.0 }
> 
> . ... CoreSight ETMV4I Trace data: size 0x50 bytes
> 
>          Idx:64; ID:10;  I_ASYNC : Alignment Synchronisation.
> 
>          Idx:76; ID:10;  I_TRACE_INFO : Trace Info.; INFO=0x0 { CC.0 }
> 
>          Idx:81; ID:10;  I_TRACE_ON : Trace On.
> 
>          Idx:82; ID:10;  I_ADDR_CTXT_L_64IS0 : Address & Context, Long, 
> 64 bit, IS0.; Addr=0x0000FFFFAD8C05A8; Ctxt: AArch64,EL0, NS;
> 
>          Idx:92; ID:10;  I_ATOM_F6 : Atom format 6.; EEEEEEN
> 
>          Idx:93; ID:10;  I_ATOM_F1 : Atom format 1.; E
> 
>          Idx:94; ID:10;  I_ADDR_L_64IS0 : Address, Long, 64 bit, IS0.; 
> Addr=0x0000AAAAAC9107E8;
> 
>          Idx:104; ID:10; I_TRACE_ON : Trace On.
> 
>          Idx:105; ID:10; I_ADDR_CTXT_L_64IS0 : Address & Context, Long, 
> 64 bit, IS0.; Addr=0x0000FFFFAD8C05E8; Ctxt: AArch64,EL0, NS;
> 
>          Idx:116; ID:10; I_ATOM_F1 : Atom format 1.; E
> 
>          Idx:117; ID:10; I_ADDR_L_64IS0 : Address, Long, 64 bit, IS0.; 
> Addr=0x0000FFFFAD8EB4E4;
> 
> 0x740 at perf.data <mailto:0x740 at perf.data> [0x8]: event: 68
> 
> .
> 
> . ... raw event: size 8 bytes
> 
> .  0000:  44 00 00 00 00 00 08 00                          D.......
> 
> 0x740 [0x8]: PERF_RECORD_FINISHED_ROUND
> 
> Aggregated stats: (excludes AUX area (e.g. instruction trace) decoded / 
> synthesized events)
> 
> Thanks,
> 
> Radhey
>