From: Oleg Nesterov <oleg@redhat.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Madhavan Srinivasan <maddy@linux.vnet.ibm.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org,
Jan Kratochvil <jan.kratochvil@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH? v2] powerpc: Hard wire PT_SOFTE value to 1 in gpr_get() too
Date: Wed, 10 Jun 2020 17:07:03 +0200 [thread overview]
Message-ID: <20200610150224.GA6793@redhat.com> (raw)
In-Reply-To: <20190917143753.GA12300@redhat.com>
Hi,
looks like this patch was forgotten.
Do you think this should be fixed or should we document that
PTRACE_GETREGS is not consistent with PTRACE_PEEKUSER on ppc64?
On 09/17, Oleg Nesterov wrote:
>
> I don't have a ppc machine, this patch wasn't even compile tested,
> could you please review?
>
> The commit a8a4b03ab95f ("powerpc: Hard wire PT_SOFTE value to 1 in
> ptrace & signals") changed ptrace_get_reg(PT_SOFTE) to report 0x1,
> but PTRACE_GETREGS still copies pt_regs->softe as is.
>
> This is not consistent and this breaks
> http://sourceware.org/systemtap/wiki/utrace/tests/user-regs-peekpoke
>
> Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com>
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> ---
> arch/powerpc/kernel/ptrace.c | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
> index 8c92feb..291acfb 100644
> --- a/arch/powerpc/kernel/ptrace.c
> +++ b/arch/powerpc/kernel/ptrace.c
> @@ -363,11 +363,36 @@ static int gpr_get(struct task_struct *target, const struct user_regset *regset,
> BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
> offsetof(struct pt_regs, msr) + sizeof(long));
>
> +#ifdef CONFIG_PPC64
> + if (!ret)
> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
> + &target->thread.regs->orig_gpr3,
> + offsetof(struct pt_regs, orig_gpr3),
> + offsetof(struct pt_regs, softe));
> +
> + if (!ret) {
> + unsigned long softe = 0x1;
> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &softe,
> + offsetof(struct pt_regs, softe),
> + offsetof(struct pt_regs, softe) +
> + sizeof(softe));
> + }
> +
> + BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
> + offsetof(struct pt_regs, softe) + sizeof(long));
> +
> + if (!ret)
> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
> + &target->thread.regs->trap,
> + offsetof(struct pt_regs, trap),
> + sizeof(struct user_pt_regs));
> +#else
> if (!ret)
> ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
> &target->thread.regs->orig_gpr3,
> offsetof(struct pt_regs, orig_gpr3),
> sizeof(struct user_pt_regs));
> +#endif
> if (!ret)
> ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
> sizeof(struct user_pt_regs), -1);
> --
> 2.5.0
>
next prev parent reply other threads:[~2020-06-10 15:09 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-17 12:12 [PATCH?] powerpc: Hard wire PT_SOFTE value to 1 in gpr_get() too Oleg Nesterov
2019-09-17 14:09 ` kbuild test robot
2019-09-17 14:37 ` [PATCH? v2] " Oleg Nesterov
2020-06-10 15:07 ` Oleg Nesterov [this message]
2020-06-11 8:52 ` Madhavan Srinivasan
2020-06-11 10:58 ` Oleg Nesterov
2020-06-11 11:11 ` Jan Kratochvil
2019-09-19 7:52 ` [PATCH?] " Michael Ellerman
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