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by skohan 2535 days ago
> building something useful out of it relies on a particular set of flags and ad-hoc implementation details of GCC (e.g. -fno-delete-null-pointer-checks).

That makes it esoteric, not random. If the Linux kernel really did produce "random output" there is no way it would serve as the backbone of the global computing infrastructure, the financial system etc.
2 comments
tomp 2534 days ago
From my observations, there seem to have been considerable efforts to avoid it being just random. Compiler & library "optimisations" have broken Linux before ("randomly") [0] [3]. Linus has ranted about this [1], multiple times [2] [3].

[0] https://lwn.net/SubscriberLink/793253/6ff74ecfb804c410/

[1] https://lkml.org/lkml/2018/6/5/769

[2] https://bugzilla.redhat.com/show_bug.cgi?id=638477#c129

[3] http://lkml.iu.edu//hypermail/linux/kernel/1407.3/00650.html

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lmm 2534 days ago
> That makes it esoteric, not random. If the Linux kernel really did produce "random output" there is no way it would serve as the backbone of the global computing infrastructure, the financial system etc.

To the extent that Linux is useful, it's not written in C. The particular binaries produced by GCC with particular flags have particular behaviour, more or less, but considered solely as a C program in terms of the C standard (i.e. behaviour on the C abstract machine), Linux does produce random output.

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