From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Anton Blanchard To: benh@kernel.crashing.org, paulus@samba.org, Ulrich.Weigand@de.ibm.com Subject: [PATCH 1/8] powerpc: PTRACE_PEEKUSR always returns FPR0 Date: Thu, 12 Dec 2013 15:59:34 +1100 Message-Id: <1386824381-14032-2-git-send-email-anton@samba.org> In-Reply-To: <1386824381-14032-1-git-send-email-anton@samba.org> References: <1386824381-14032-1-git-send-email-anton@samba.org> Cc: linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Ulrich Weigand 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 Signed-off-by: Anton Blanchard --- arch/powerpc/kernel/ptrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index 75fb404..2e3d2bf 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -1555,7 +1555,7 @@ long arch_ptrace(struct task_struct *child, long request, flush_fp_to_thread(child); if (fpidx < (PT_FPSCR - PT_FPR0)) - memcpy(&tmp, &child->thread.fp_state.fpr, + memcpy(&tmp, &child->thread.TS_FPR(fpidx), sizeof(long)); else tmp = child->thread.fp_state.fpscr; @@ -1588,7 +1588,7 @@ long arch_ptrace(struct task_struct *child, long request, flush_fp_to_thread(child); if (fpidx < (PT_FPSCR - PT_FPR0)) - memcpy(&child->thread.fp_state.fpr, &data, + memcpy(&child->thread.TS_FPR(fpidx), &data, sizeof(long)); else child->thread.fp_state.fpscr = data; -- 1.8.3.2