powerpc: PTRACE_PEEKUSR always returns FPR0
authorUlrich Weigand <Ulrich.Weigand@de.ibm.com>
Thu, 12 Dec 2013 04:59:34 +0000 (15:59 +1100)
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>
Fri, 13 Dec 2013 04:48:33 +0000 (15:48 +1100)
commit36aa1b180e7398e2bd27642760bfaa4ad8c65ab6
tree3fe876673f333b130bd004daa62c566c8bd09f1d
parente641eb03ab2b0f065fa5e64b4202fb5b0441b427
powerpc: PTRACE_PEEKUSR always returns FPR0

There is a bug in using ptrace to access FPRs via PTRACE_PEEKUSR /
PTRACE_POKEUSR. In effect, trying to access any of the FPRs always
really accesses FPR0, which does seriously break debugging :-)

The problem seems to have been introduced by commit 3ad26e5c4459d
(Merge branch 'for-kvm' into next).

[ It is indeed a merge conflict between Paul's FPU/VSX state rework
and my LE patches - Anton ]

Signed-off-by: Ulrich Weigand <Ulrich.Weigand@de.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
arch/powerpc/kernel/ptrace.c