[Issue] vmlinux is not built reproducibly in arm[,64] architectures

[Issue] vmlinux is not built reproducibly in arm[,64] architectures

[Venkata.Pyla]

Hi isar team,

Thanks for your help always,

I am verifying reproducible builds in child project (isar-cip-core) and found 'vmlinux' is not reproducibly built in arm and arm64 architectures, whereas in amd64 it is built reproducibly.

Reported in isar-cip-core project for your reference [1] 
The issue is also present in isar with custom linux enabled
meta-isar/conf/machine/qemuarm64.conf
-KERNEL_NAME ?= "arm64"
+KERNEL_NAME ?= "cip"


The diffoscope output shows some differences in vdso section of the vmlinux output, I am debugging this but any idea from arm[,64] architecture respective any settings are missing for reproducible builds?

│   --- image1-content
├── +++ image2-content
│ ├── ./var/lib/dpkg/info/linux-image-cip.md5sums
│ │ @@ -1,10 +1,10 @@
│ │  490c4ba60fb170b0259bf898e27d7e8c  boot/System.map-5.10.161-cip23
│ │  60e94e9441f9647193636795547d66cc  boot/config-5.10.161-cip23
│ │ -cae0b790beb11d0e42040464a87520c0  boot/vmlinux-5.10.161-cip23
│ │ +c5605098a733912b596abb725eacc38e  boot/vmlinux-5.10.161-cip23
│ │  d41d8cd98f00b204e9800998ecf8427e  lib/modules/5.10.161-cip23/.fresh-install
│ │  1b80683350c5ff5bd598663595ac5c01  lib/modules/5.10.161-cip23/kernel/arch/arm64/lib/xor-neon.ko
│ │  91baa60d06864fa2a93539171b891677  lib/modules/5.10.161-cip23/kernel/crypto/blake2b_generic.ko
│ │  6582d4c520c993f1c33b1f6c16361bcf  lib/modules/5.10.161-cip23/kernel/crypto/ccm.ko
│ │  429b6945eb477da88aff29bc6b087837  lib/modules/5.10.161-cip23/kernel/crypto/chacha_generic.ko
│ │  7bc46492f0180d4670674f6e2022c5d8  lib/modules/5.10.161-cip23/kernel/crypto/cmac.ko
│ │  14bda2f376762fd0ac5be7459c8727fe  lib/modules/5.10.161-cip23/kernel/crypto/ctr.ko
│ ├── ./boot/vmlinux-5.10.161-cip23
│ │ @@ -648997,16 +648997,16 @@
│ │  009e7240: 7664 736f 2e73 6f2e 3100 4c49 4e55 585f  vdso.so.1.LINUX_
│ │  009e7250: 322e 362e 3339 0000 0000 0200 0200 0200  2.6.39..........
│ │  009e7260: 0200 0200 0000 0000 0100 0100 0100 0100  ................
│ │  009e7270: a1bf ee0d 1400 0000 1c00 0000 5a00 0000  ............Z...
│ │  009e7280: 0000 0000 0100 0000 0200 0100 89cb 5f07  .............._.
│ │  009e7290: 1400 0000 0000 0000 6a00 0000 0000 0000  ........j.......
│ │  009e72a0: 0400 0000 1400 0000 0300 0000 474e 5500  ............GNU.
│ │ -009e72b0: e674 f5e9 e043 107f 7173 0e8c d5d2 c056  .t...C..qs.....V
│ │ -009e72c0: 8c2a 4493 0600 0000 0400 0000 0000 0000  .*D.............
│ │ +009e72b0: c126 cac3 099e e721 ba66 072c 5d37 1f2b  .&.....!.f.,]7.+
│ │ +009e72c0: 0dce 6404 0600 0000 0400 0000 0000 0000  ..d.............
│ │  009e72d0: 4c69 6e75 7800 0000 a10a 0500 0600 0000  Linux...........
│ │  009e72e0: 0100 0000 0001 0000 4c69 6e75 7800 0000  ........Linux...
│ │  009e72f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
│ │  009e7300: 3f23 03d5 1f3c 0071 e805 0054 2200 8052  ?#...<.q...T"..R
│ │  009e7310: 6310 8152 4220 c01a 44e7 fe10 4300 036a  c..RB ..D...C..j
│ │  009e7320: 4006 0054 88d0 208b 0d00 b012 8700 40b9  @..T.. .......@.
│ │  009e7330: 2705 0037 bf39 03d5 8204 40b9 4204 0034  '..7.9....@.B..4
│ │ @@ -868620,16 +868620,16 @@
│ │  00d410b0: b4d6 c2ff 2873 c9ff 14d7 c2ff 2873 c9ff  ....(s......(s..
│ │  00d410c0: f899 c3ff 2873 c9ff a49a c3ff 2873 c9ff  ....(s......(s..
│ │  00d410d0: 90c7 c3ff 2873 c9ff 28c8 c3ff 2c73 c9ff  ....(s..(...,s..
│ │  00d410e0: 10b2 c5ff 2c73 c9ff 3c00 c6ff 2c73 c9ff  ....,s..<...,s..
│ │  00d410f0: ac68 c9ff b068 c9ff bc68 c9ff c468 c9ff  .h...h...h...h..
│ │  00d41100: b868 c9ff bc68 c9ff cc68 c9ff d068 c9ff  .h...h...h...h..
│ │  00d41110: 0400 0000 1400 0000 0300 0000 474e 5500  ............GNU.
│ │ -00d41120: ffa9 1f38 b4c4 f598 891a 46a9 75e0 f951  ...8......F.u..Q
│ │ -00d41130: 52e7 7014 0600 0000 0100 0000 0001 0000  R.p.............
│ │ +00d41120: 8916 5cd1 9d12 1d64 f8c1 3edb 5452 0360  ..\....d..>.TR.`
│ │ +00d41130: 2dac 2730 0600 0000 0100 0000 0001 0000  -.'0............
│ │  00d41140: 4c69 6e75 7800 0000 0000 0000 0000 0000  Linux...........
│ │  00d41150: 0000 0000 0000 0000 0000 0000 0000 0000  ................
│ │  00d41160: 0000 0000 0000 0000 0000 0000 0000 0000  ................
│ │  00d41170: 0000 0000 0000 0000 0000 0000 0000 0000  ................
│ │  00d41180: 0000 0000 0000 0000 0000 0000 0000 0000  ................
│ │  00d41190: 0000 0000 0000 0000 0000 0000 0000 0000  ................
│ │  00d411a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................


[1] https://gitlab.com/cip-project/cip-core/isar-cip-core/-/issues/56

Thanks,
Venkata.