[Question] Why embed the kernel version in LSOF_VSTR?

Hello!

the test infrastructure for Reproducible Arch Linux has built lsof, trying to match the original binary distributed to users (in the same path, with the same compiler/library versions and noticed this difference:

│ │ ├── readelf --wide --decompress --hex-dump=.rodata {}
│ │ │ @@ -519,15 +519,15 @@
│ │ │    0x00025040 6663662d 70726f74 65637469 6f6e202d fcf-protection -
│ │ │    0x00025050 67202d66 66696c65 2d707265 6669782d g -ffile-prefix-
│ │ │    0x00025060 6d61703d 2f627569 6c642f6c 736f662f map=/build/lsof/
│ │ │    0x00025070 7372633d 2f757372 2f737263 2f646562 src=/usr/src/deb
│ │ │    0x00025080 75672f6c 736f6620 2d666c74 6f3d6175 ug/lsof -flto=au
│ │ │    0x00025090 746f202d 445f4649 4c455f4f 46465345 to -D_FILE_OFFSE
│ │ │    0x000250a0 545f4249 54533d36 34202d44 4c534f46 T_BITS=64 -DLSOF
│ │ │ -  0x000250b0 5f565354 523d2236 2e372e38 2d617263 _VSTR="6.7.8-arc
│ │ │ +  0x000250b0 5f565354 523d2236 2e372e34 2d617263 _VSTR="6.7.4-arc
│ │ │    0x000250c0 68312d31 22202d44 48415353 45435552 h1-1" -DHASSECUR
│ │ │    0x000250d0 49545920 2d444841 534e4f53 4f434b53 ITY -DHASNOSOCKS
│ │ │    0x000250e0 45435552 49545920 2d492f75 73722f69 ECURITY -I/usr/i
│ │ │    0x000250f0 6e636c75 64652f74 69727063 00000000 nclude/tirpc....
│ │ │    0x00025100 2d576c2c 2d4f3120 2d576c2c 2d2d736f -Wl,-O1 -Wl,--so
│ │ │    0x00025110 72742d63 6f6d6d6f 6e202d57 6c2c2d2d rt-common -Wl,--
│ │ │    0x00025120 61732d6e 65656465 64202d57 6c2c2d7a as-needed -Wl,-z

It seems LSOF_VSTR contains the output of $(uname -r), the kernel version number, is there a reason for this?

It seems the LSOF_VSTR string itself isn't actually embedded (used?) anywhere, but it ends up in CFLAGS which the binary records for lsof -v version output:

% lsof -v                   
lsof version information:
    revision: 4.99.3
    copyright notice: Copyright 1998 Purdue Research Foundation. All rights reserved.
    latest revision: https://github.com/lsof-org/lsof
    latest FAQ: https://github.com/lsof-org/lsof/blob/master/00FAQ
    latest (non-formatted) man page: https://github.com/lsof-org/lsof/blob/master/Lsof.8
    constructed on: x86_64-pc-linux-gnu
    compiler: gcc
    compiler version: 13.2.1 20230801 (GCC) 
    compiler flags: -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -fexceptions         -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security         -fstack-clash-protection -fcf-protection -g -ffile-prefix-map=/build/lsof/src=/usr/src/debug/lsof -flto=auto -D_FILE_OFFSET_BITS=64 -DLSOF_VSTR="6.7.8-arch1-1" -DHASSECURITY -DHASNOSOCKSECURITY -I/usr/include/tirpc
    loader flags: -Wl,-O1 -Wl,--sort-common -Wl,--as-needed -Wl,-z,relro -Wl,-z,now          -Wl,-z,pack-relative-relocs -flto=auto -ltirpc
    features enabled: ipv6 ptyept rpc soopt sostate tasks uxsockept
    Only root can list all files, but anyone can list socket files.
    /dev warnings are disabled.
    Kernel ID check is disabled.

Can this be set to an empty string, or maybe removed even? :)

Thanks!

lsof-org / lsof

[Question] Why embed the kernel version in LSOF_VSTR? #310