Search notes:

init/version-timestamp.c

const char linux_proc_banner[] =
        "%s version %s"
        " (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ")"
        " (" LINUX_COMPILER ") %s\n";

See also

init/version-timestamp.c is included by init/version.c.
The values of the macros UTS_RELEASE, LINUX_COMPILE_BY etc. are defined in include/generated/compile.h.

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