Re: [GIT PULL] parisc architecture patch for v3.18

From: Helge Deller
Date: Mon Oct 13 2014 - 16:25:12 EST


On 10/13/2014 03:41 PM, One Thousand Gnomes wrote:
On Sun, 12 Oct 2014 12:08:37 +0200
Helge Deller <deller@xxxxxx> wrote:

Hi Linus,

please pull one patch for the parisc architecture for kernel 3.18 from
git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux.git parisc-3.18-1

This patch intentionally breaks the ABI on PARISC Linux!

It assigns new numbers to SIGSTKFLT, SIGXCPU, SIGXFSZ and SIGSYS so that
those are below 32 and thus leaves us with 32 RT signals like other
Linux architectures (SIGRTMIN now becomes 32 instead of 37).

Even if it breaks the ABI, it doesn't seem to have any visible impact on
existing userspace applications.

I somehow doubt your kill command magically corrects its signal numbering
table. Likewise what does gdb do given a core dump that died from one of
those signals, and what does your shell report if you kill one that way.
It seems to me your minimal set of binaries to swap to get it right is
non-zero but not problematic (libc, kill, shells, top, gdb) ?

My patch of course just marks the start of a transition phase, in which
some few applications need to be rebuilt (libc as the most important one).
But after all it makes a somewhat smooth transition possible, and as I
wrote in the commit message this is the best solution (out of 3) with the
least impact which we have.
I can however really only think of one app that actually *used* SIGXCPU,
and that was to respawn itself to avoid annoying sysadmin set CPU limits
anyway.

:-)

Helge
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