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From:   Guo Ren <guoren@kernel.org>
Date:   Fri, 5 May 2023 18:01:25 +0800
Message-ID: <CAJF2gTRqdP-RVSMshwzJuAcm1bBeg1-wZU_k_Oo409=O4QZR-w@mail.gmail.com>
Subject: Re: [PATCH] riscv: uprobes: Restore thread.bad_cause
To:     Tiezhu Yang <yangtiezhu@loongson.cn>
Cc:     Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        loongson-kernel@lists.loongnix.cn
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Thx for fixup.

Reviewed-by: Guo Ren <guoren@kernel.org>

On Sun, Apr 23, 2023 at 9:42=E2=80=AFAM Tiezhu Yang <yangtiezhu@loongson.cn=
> wrote:
>
> thread.bad_cause is saved in arch_uprobe_pre_xol(), it should be restored
> in arch_uprobe_{post,abort}_xol() accordingly, otherwise the save operati=
on
> is meaningless, this change is similar with x86 and powerpc.
>
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> ---
>  arch/riscv/kernel/probes/uprobes.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/arch/riscv/kernel/probes/uprobes.c b/arch/riscv/kernel/probe=
s/uprobes.c
> index c976a21..194f166 100644
> --- a/arch/riscv/kernel/probes/uprobes.c
> +++ b/arch/riscv/kernel/probes/uprobes.c
> @@ -67,6 +67,7 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, s=
truct pt_regs *regs)
>         struct uprobe_task *utask =3D current->utask;
>
>         WARN_ON_ONCE(current->thread.bad_cause !=3D UPROBE_TRAP_NR);
> +       current->thread.bad_cause =3D utask->autask.saved_cause;
>
>         instruction_pointer_set(regs, utask->vaddr + auprobe->insn_size);
>
> @@ -102,6 +103,7 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprob=
e, struct pt_regs *regs)
>  {
>         struct uprobe_task *utask =3D current->utask;
>
> +       current->thread.bad_cause =3D utask->autask.saved_cause;
>         /*
>          * Task has received a fatal signal, so reset back to probbed
>          * address.
> --
> 2.1.0
>


--=20
Best Regards
 Guo Ren