Re: [PATCH v3 3/3] Dynamic core regset sections support

[Andreas Arnez <arnez at linux dot vnet dot ibm dot com>]

Mark Kettenis <mark.kettenis@xs4all.nl> writes:

> Sorry, but I really don't like the obfuscation that this diff brings
> to the amd64 & i186 Linux targets.

If you can point me specifically to the spot where the obfuscation
occurs, I'll do my best to clean it up.  A side-intention with the patch
actually was to *improve* readability, mainly by avoiding copy- & pasted
array initializers and distributed code logic.  And indeed, while
offering improved flexibility, the patch overall saves 60 lines of code:

 11 files changed, 266 insertions(+), 326 deletions(-)

amd64 is the only architecture that suffers from a slight code increase
(8 lines).

> Is there really no other way to this?

There are always other ways ;-) I already implemented some of them, and
the proposed patch seemed like the best approach to me.

> Is it really that bad to write out the invalid TDB registers?  If GDB
> recognizes them as invalid, this shouldn't be a big issue should it?

Do you mean to always write the TDB regset into the core dump, like
without the patch?  And then add some logic such that GDB recognizes
zero values in the register note section as invalid and clears the
regset?  Or do I misinterpret your suggestion?

BTW, I wonder how transaction diagnostics works on x86.  E.g., when an
illegal instruction occurs within a hardware transaction, will the core
dump contain the address of the violating instruction?