Re: gdb 8.3.1 truncated register in remote g packet

Reinoud Koornstra
2019-11-01T18:24:36Z

On Fri, Nov 1, 2019 at 9:11 AM Luis Machado <luis.machado@linaro.org> wrote:

> Hi Reinoud,
>
> Hi Luis,
Thanks for your response.

>
> That error means your remote arm32 machine's debugging stub doesn't
> agree with GDB in terms of the register set. GDB is likely assuming
> register set A and the debugging stub is assuming register set B.
>
> You can check what the debugging stub is sending via "set debug remote
> 1". If it supports XML register descriptions, you'll see data flying by.
>
> If it doesn't, then GDB is probably making a guess as to what the proper
> register set is.
>
> In summary, i think we need more data in order to make an informer guess
> on what is going wrong here, but probably GDB and the debugging stub are
> not in sync in terms of registers.
>
Here's more output with debug remote.
sudo gdb-for-arm/bin/arm-linux-gnueabihf-gdb ./vmlinux
GNU gdb (GDB) 8.3.1
Copyright (C) 2019 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html
>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "--host=x86_64-pc-linux-gnu
--target=arm-linux-gnueabihf".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./vmlinux...
(gdb) set serial baud 115200
(gdb) set debug remote 1
(gdb) target remote /dev/ttyUSB4
Remote debugging using /dev/ttyUSB4
Sending packet:
$qSupported:multiprocess+;swbreak+;hwbreak+;qRelocInsn+;fork-events+;vfork-events+;exec-events+;vContSupported+;QThreadEvents+;no-resumed+#df...Ack
Packet received:
Packet qSupported (supported-packets) is NOT supported
Sending packet: $vMustReplyEmpty#3a...Ack
Packet received:
Sending packet: $Hg0#df...Ack
Packet received: OK
Sending packet: $qTStatus#49...Ack
Packet received:
Packet qTStatus (trace-status) is NOT supported
Sending packet: $?#3f...Ack
Packet received: S05
Sending packet: $qfThreadInfo#bb...Ack
Packet received:
mfffffffe,fffffffd,01,02,03,05,06,07,08,09,0a,0b,0c,0d,0e,0f,10,11,12
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
m0147,014a,014c,0164,016f,0198,01a3,01a9,01dc,01ea,04b3,0502,0511,0512,0513,0514,0515
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
m0523,0524,0525,0535,0540,0548,0614,098d,0992,0993,09bf,09c2,09c8,09cd,09ce,09db,09e1
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
m09ea,09f7,09ff,0a36,0a3e,0a4b,0a51,0a57,0a58,0a5a,0a5b,0a5d,0a5e,0a5f,0aa4,0aa6,0aa8
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
m0af2,0af3,0af4,0afa,0afc,0b7d,0b9a,0b9b,0b9c,0c1d,0cb8,0b96,0be9,0beb,0bf7,0bfb,0bfc
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
m0bfd,0bfe,0bff,0c00,0c01,0c02,0c03,0c04,0c05,0c06,0c60,0c65,0c67,0c68,0c6d,0c6e,0c7c
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
m0c7d,0c7f,0ce5,0df6,0e2f,0e39,0e3b,0e3d,0e5d,0e3e,0e3f,0e41,0e8c,0e8e,0ea3,0eaf,0ebc
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
m0ebe,0ebf,0ec1,0ec2,0ec5,0ec7,0ec9,0ed0,0ed3,0ed4,0eca,0ecc,0ece,0ecf,0ed2,0edc,1061
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
m1105,13fb,144c,145a,14b6,14c8,14cd,14e0,14f4,150b,1510,1511,1512,1514,1699,169b,169d
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
m169e,169f,16a0,16a1,16a2,16cd,16cf,16d1,16d2,16d3,16d7,16dd,16de,16df,16e0,16e1,16e2
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
m16e3,16e4,16e6,1961,1c81,1c82,1c83,1c84,1c85,1c86,1c87,16f2,16f3,16f5,16f6,16fc,1758
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
m1759,175a,16f7,16f8,16fa,1704,1706,1719,1723,1724,1725,1734,1735,1741,1744,1747,1877
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
m187b,187d,1880,188f,1893,193b,1949,194a,194f,1952,1957,1a78,1c75,1c77,1c9d,1eb4,1eb6
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
m1eb8,1ebe,29ed,0149,096c,1334,184d,1df6,1f3f,2123,2165,2175,2183
Sending packet: $qsThreadInfo#c8...Ack
Packet received:
Sending packet: $qAttached#8f...Ack
Packet received:
Packet qAttached (query-attached) is NOT supported
Sending packet: $Hc-1#09...Ack
Packet received: OK
Sending packet: $qC#b4...Ack
Packet received: QC0aa8
Sending packet: $qOffsets#4b...Ack
Packet received:
Sending packet: $g#67...Ack
Packet received:
0000000001000000b0829e80ac829e8054829880b4a698806700000013000060060000000000000000000000cc3e27bed03e27bec03e27be10200a80581f0a8000000000000000000000000000000000000000000000000000000000000000000000000000000000
Truncated register 19 in remote 'g' packet

>
>
Thanks, Reinoud.