Subject: Re: [PATCH v14 13/15] selftests/powerpc: Add ptrace tests for TM SPR registers

From: Cyril Bur <[email-masked]>
Date: Wed, 14 Sep 2016 15:04:12 +1000

On Mon, 2016-09-12 at 15:33 +0800, [email-masked] wrote:
> From: Anshuman Khandual <[email-masked]>
> 
> This patch adds ptrace interface test for TM SPR registers. This
> also adds ptrace interface based helper functions related to TM
> SPR registers access.
> 

I'm seeing this one fail a lot, it does occasionally succeed but fails
a lot on my test setup.

I use qemu on a power8 for most of my testing:
qemu-system-ppc64 --enable-kvm -machine pseries,accel=kvm,usb=off -m
4096 -realtime mlock=off -smp 4,sockets=1,cores=2,threads=2 -nographic
-vga none

> Signed-off-by: Anshuman Khandual <[email-masked]>
> Signed-off-by: Simon Guo <[email-masked]>
> ---
>  tools/testing/selftests/powerpc/ptrace/Makefile    |   3 +-
>  .../selftests/powerpc/ptrace/ptrace-tm-spr.c       | 186
> +++++++++++++++++++++
>  tools/testing/selftests/powerpc/ptrace/ptrace.h    |  35 ++++
>  3 files changed, 223 insertions(+), 1 deletion(-)
>  create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-tm-
> spr.c
> 
> diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile
> b/tools/testing/selftests/powerpc/ptrace/Makefile
> index 797840a..f34670e 100644
> --- a/tools/testing/selftests/powerpc/ptrace/Makefile
> +++ b/tools/testing/selftests/powerpc/ptrace/Makefile
> @@ -1,7 +1,8 @@
>  TEST_PROGS := ptrace-ebb ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr
> \
>  ptrace-tar ptrace-tm-tar ptrace-tm-spd-tar ptrace-vsx ptrace-tm-vsx
> \
> -ptrace-tm-spd-vsx
> +ptrace-tm-spd-vsx ptrace-tm-spr
>  
> +include ../../lib.mk
>  
>  all: $(TEST_PROGS)
>  CFLAGS += -m64
> diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
> b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
> new file mode 100644
> index 0000000..2863070
> --- /dev/null
> +++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
> @@ -0,0 +1,186 @@
> +/*
> + * Ptrace test TM SPR registers
> + *
> + * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version
> + * 2 of the License, or (at your option) any later version.
> + */
> +#include "ptrace.h"
> +
> +/* Tracee and tracer shared data */
> +struct shared {
> +	int flag;
> +	struct tm_spr_regs regs;
> +};
> +unsigned long tfhar;
> +
> +int shm_id;
> +volatile struct shared *cptr, *pptr;
> +
> +int shm_id1;
> +volatile int *cptr1, *pptr1;
> +
> +#define TM_SCHED	0xde0000018c000001
> +#define TM_KVM_SCHED	0xe0000001ac000001
> +
> +int validate_tm_spr(struct tm_spr_regs *regs)
> +{
> +	if (regs->tm_tfhar != tfhar)
> +		return TEST_FAIL;
> +
> +	if ((regs->tm_texasr != TM_SCHED) && (regs->tm_texasr !=
> TM_KVM_SCHED))
> +		return TEST_FAIL;

The above condition fails, should this test try again if this condition
is true, rather than fail?

> +
> +	if ((regs->tm_texasr == TM_KVM_SCHED) && (regs->tm_tfiar !=
> 0))
> +		return TEST_FAIL;
> +
> +	return TEST_PASS;
> +}
> +

[snip]