[patch 0/3, nios2] unbreak nios2-linux-gnu GDB

Sandra Loosemore
2015-04-23T18:49:47Z

GDB support for nios2-linux-gnu became broken during the time when glibc
and kernel support for that target was transitioning to the upstream
repositories. Both ports were accepted around the first of the year,
but then the initial 3.19 kernel was not usable for testing due to some
unrelated problems with the ethernet support, it took a long time to
track down a bug that caused a kernel hang, and then we ran into some
additional bugs with kernel cache flushing. The icache flush issues
were fixed in time for the 4.0 kernel release and GDB is working pretty
well with that kernel version now for manual use, but to get consistent
results from automated testing I had to apply an additional local patch
to flush the dcache more aggressively. I expect some version of that
will make it into future kernel releases since Altera is aware of the
trouble now.

There are 3 patches:

(1) revert to using "trap 31" for breakpoints
(2) use PTRACE_GETREGSET/SETREGSET in gdbserver
(3) fixes for new implementation of signal handler trampolines

Since the old out-of-tree kernel/glibc ports are now obsolete, we
haven't tried to maintain backward compatibility in these patches.

Yao, I noticed that you haven't updated your e-mail address in
MAINTAINERS; are you still acting as nios2 maintainer?

-Sandra