Lightning: 'make check' failed on 32bit armv7l

[Chirimen-Jako]

Issue and Steps to Reproduce

What can I provide any other information?

$ make check
...(The other VALGRIND tests succeeded so far)...
VALGRIND=1 valgrind -q --error-exitcode=7 --track-origins=yes --leak-check=full --show-reachable=yes --errors-for-leak-kinds=all connectd/test/run-initiator-success > /dev/null
==27974== Source and destination overlap in memcpy(0xbda56664, 0xbda56664, 84)
==27974==    at 0x4844ECC: memcpy (vg_replace_strmem.c:1023)
==27974==    by 0x1410E5: secp256k1_ge_neg (in /home/satoshi/lightning/connectd/test/run-initiator-success)
==27974==
Makefile:586: recipe for target 'unittest/connectd/test/run-initiator-success' failed
make: *** [unittest/connectd/test/run-initiator-success] Error 7

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.5 LTS
Release:        18.04
Codename:       bionic

$ uname -a
Linux odroid 4.14.111-158 #1 SMP PREEMPT Tue Apr 16 12:26:31 -03 2019 armv7l armv7l armv7l GNU/Linux

$ cat /proc/cpuinfo
processor       : 0
model name      : ARMv7 Processor rev 3 (v7l)
BogoMIPS        : 90.00
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 3

processor       : 1
model name      : ARMv7 Processor rev 3 (v7l)
BogoMIPS        : 90.00
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 3

processor       : 2
model name      : ARMv7 Processor rev 3 (v7l)
BogoMIPS        : 90.00
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 3

processor       : 3
model name      : ARMv7 Processor rev 3 (v7l)
BogoMIPS        : 90.00
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 3

processor       : 4
model name      : ARMv7 Processor rev 3 (v7l)
BogoMIPS        : 120.00
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x2
CPU part        : 0xc0f
CPU revision    : 3

processor       : 5
model name      : ARMv7 Processor rev 3 (v7l)
BogoMIPS        : 120.00
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x2
CPU part        : 0xc0f
CPU revision    : 3

processor       : 6
model name      : ARMv7 Processor rev 3 (v7l)
BogoMIPS        : 120.00
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x2
CPU part        : 0xc0f
CPU revision    : 3

processor       : 7
model name      : ARMv7 Processor rev 3 (v7l)
BogoMIPS        : 120.00
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x2
CPU part        : 0xc0f
CPU revision    : 3

Hardware        : ODROID-XU4
Revision        : 0100
Serial          : 0000000000000000
$

getinfo output

{
"id": "036c518bbbf7afd2dd00ec145b501b782f1ec4112928e650db78319c52ee05b7fb",
"alias": "ChirimenJako",
"color": "00fed9",
"num_peers": 1,
"num_pending_channels": 0,
"num_active_channels": 1,
"num_inactive_channels": 0,
"address": [],
"binding": [
{
"type": "ipv4",
"address": "0.0.0.0",
"port": 9735
}
],
"version": "v0.9.2rc1-6-gcd7d5cd",
"blockheight": 651263,
"network": "bitcoin",
"msatoshi_fees_collected": 4001,
"fees_collected_msat": "4001msat",
"lightning-dir": "/home/bitcoin/.lightning/bitcoin",
"warning_bitcoind_sync": "Bitcoind is not up-to-date with network."
}

[jsarenik]

Trying to reproduce now on my arm box.

[jsarenik]

Reproduced very easily (./configure; make; make check) also on Ubuntu 20.04 ARMv7 on current master (i.e. v0.9.2rc2, ce0888d7d6756d8ccb862e43d918fa3128e4f0dc)

VALGRIND=1 valgrind -q --error-exitcode=7 --track-origins=yes --leak-check=full --show-reachable=yes --errors-for-leak-kinds=all connectd/test/run-initiator-success > /dev/null
==14367== Source and destination overlap in memcpy(0xbdc4289c, 0xbdc4289c, 84)
==14367==    at 0x48464BC: memcpy (vg_replace_strmem.c:1036)
==14367==    by 0x141839: secp256k1_ge_neg (in /root/src/lightning/connectd/test/run-initiator-success)
==14367== 
make: *** [Makefile:586: unittest/connectd/test/run-initiator-success] Error 7

Thank you @Chirimen-Jako for reporting this!

[rustyrussell]

Ha, this can actually be safely ignored, though I'm not sure whether gcc is allowed to take this liberty.

[jsarenik]

Tested on arm64 and the error is not reproducible there. This is some info:

$ cat /etc/os-release 
PRETTY_NAME="Debian GNU/Linux bullseye/sid"
NAME="Debian GNU/Linux"
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"
$ uname -rms
Linux 5.4.0-qcomlt-arm64 aarch64
$ gcc --version
gcc (Debian 10.2.0-16) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ valgrind --version
valgrind-3.16.1
$ cat /proc/cpuinfo 
processor   : 0
BogoMIPS    : 38.40
Features    : fp asimd evtstrm crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant : 0x0
CPU part    : 0xd03
CPU revision    : 0

processor   : 1
BogoMIPS    : 38.40
Features    : fp asimd evtstrm crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant : 0x0
CPU part    : 0xd03
CPU revision    : 0

processor   : 2
BogoMIPS    : 38.40
Features    : fp asimd evtstrm crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant : 0x0
CPU part    : 0xd03
CPU revision    : 0

processor   : 3
BogoMIPS    : 38.40
Features    : fp asimd evtstrm crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant : 0x0
CPU part    : 0xd03
CPU revision    : 0

[whitslack]

Ha, this can actually be safely ignored, though I'm not sure whether gcc is allowed to take this liberty.

Maybe just call memmove and call it a day? The extra test and branch isn't going to make much of a difference. Plus, it's even possible that memmove might have logic to avoid moving any bytes at all when source and destination pointers are equal.