[DTrace-devel] [PATCH v2 2/2] tests, actions: fix tst.symmod.sh

[Nick Alcock]

On 13 Feb 2024, Eugene Loh via DTrace-devel told this:

> The comment about never using shuf does not belong in the commit message.
> 
> The indentation in the file is with tabs, so that style should be preserved.

... it was? Whoops :)

> Instead of inflooping (in flooping?), how about "infinitely looping".  (I do find some occurrences of "inflooping" on the internet,
> but might as well be less slangy?)

I find 'infinitely looping' clunky. "Looping infinitely" is even
clunkier. Inflooping is an established term of art, frankly.
(Irrelevant given the below anyway.)

> Anyhow, instead of the shuffle approach, how about "awk 'NF == 4' /proc/kallsyms" to a temp file and use that?

Oh yeah that would work, though I don't see what's wrong with using
shuf...

> But even that won't be enough.  Once you allow "any" symbol from
> /proc/kallsyms, you risk encountering symbols that DTrace doesn't know
> about.  Stuff like __ksymtab* and __kstrtab* and others.  I think we
> filter that stuff out in dt_modsym_addsym().  The same filtering is
> done in test/unittest/consumer/tst.symbols.c.  It's the headache one
> saves by going after a specific symbol like ksys_write.

... but doing *that* seems like it would render the test nearly useless.

the fact that tst.symmod.sh as I found it was broken for *all modules*
even though much of its code was meant to handle them suggests that
whatever it was intended to test, it wasn't actually testing it. (There
are no comments describing what it's for, which makes it hard to figure
out how to preserve that property when changing it.)

(I mean among other things it was carefully selecting a guaranteed
non-modular symbol, so what all this code to figure out what module it
was in was for, even if it had worked, I have no idea...)