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References: <20220715061027.1612149-1-kaleshsingh@google.com> <20220715061027.1612149-3-kaleshsingh@google.com>
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From:   Fuad Tabba <tabba@google.com>
Date:   Fri, 15 Jul 2022 14:58:33 +0100
Message-ID: <CA+EHjTxpYgEYX4MRAYAVyptPZa6jUV2b_c_E4kLEMRcj6jsLUQ@mail.gmail.com>
Subject: Re: [PATCH v4 02/18] arm64: stacktrace: Factor out on_accessible_stack_common()
To:     Kalesh Singh <kaleshsingh@google.com>
Cc:     maz@kernel.org, mark.rutland@arm.com, broonie@kernel.org,
        madvenka@linux.microsoft.com, will@kernel.org, qperret@google.com,
        james.morse@arm.com, alexandru.elisei@arm.com,
        suzuki.poulose@arm.com, catalin.marinas@arm.com,
        andreyknvl@gmail.com, russell.king@oracle.com,
        vincenzo.frascino@arm.com, mhiramat@kernel.org, ast@kernel.org,
        drjones@redhat.com, wangkefeng.wang@huawei.com, elver@google.com,
        keirf@google.com, yuzenghui@huawei.com, ardb@kernel.org,
        oupton@google.com, linux-arm-kernel@lists.infradead.org,
        kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
        android-mm@google.com, kernel-team@android.com
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Hi Kalesh,

On Fri, Jul 15, 2022 at 7:10 AM Kalesh Singh <kaleshsingh@google.com> wrote:
>
> Move common on_accessible_stack checks to stacktrace/common.h. This is
> used in the implementation of the nVHE hypervisor unwinder later in
> this series.
>
> Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
> ---

Reviewed-by: Fuad Tabba <tabba@google.com>

Thanks,
/fuad


>  arch/arm64/include/asm/stacktrace.h        |  8 ++------
>  arch/arm64/include/asm/stacktrace/common.h | 18 ++++++++++++++++++
>  2 files changed, 20 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
> index 79f455b37c84..a4f8b84fb459 100644
> --- a/arch/arm64/include/asm/stacktrace.h
> +++ b/arch/arm64/include/asm/stacktrace.h
> @@ -56,7 +56,6 @@ static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
>                         struct stack_info *info) { return false; }
>  #endif
>
> -
>  /*
>   * We can only safely access per-cpu stacks from current in a non-preemptible
>   * context.
> @@ -65,8 +64,8 @@ static inline bool on_accessible_stack(const struct task_struct *tsk,
>                                        unsigned long sp, unsigned long size,
>                                        struct stack_info *info)
>  {
> -       if (info)
> -               info->type = STACK_TYPE_UNKNOWN;
> +       if (on_accessible_stack_common(tsk, sp, size, info))
> +               return true;
>
>         if (on_task_stack(tsk, sp, size, info))
>                 return true;
> @@ -74,12 +73,9 @@ static inline bool on_accessible_stack(const struct task_struct *tsk,
>                 return false;
>         if (on_irq_stack(sp, size, info))
>                 return true;
> -       if (on_overflow_stack(sp, size, info))
> -               return true;
>         if (on_sdei_stack(sp, size, info))
>                 return true;
>
>         return false;
>  }
> -
>  #endif /* __ASM_STACKTRACE_H */
> diff --git a/arch/arm64/include/asm/stacktrace/common.h b/arch/arm64/include/asm/stacktrace/common.h
> index 64ae4f6b06fe..f58b786460d3 100644
> --- a/arch/arm64/include/asm/stacktrace/common.h
> +++ b/arch/arm64/include/asm/stacktrace/common.h
> @@ -62,6 +62,9 @@ struct unwind_state {
>         struct task_struct *task;
>  };
>
> +static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
> +                                    struct stack_info *info);
> +
>  static inline bool on_stack(unsigned long sp, unsigned long size,
>                             unsigned long low, unsigned long high,
>                             enum stack_type type, struct stack_info *info)
> @@ -80,6 +83,21 @@ static inline bool on_stack(unsigned long sp, unsigned long size,
>         return true;
>  }
>
> +static inline bool on_accessible_stack_common(const struct task_struct *tsk,
> +                                             unsigned long sp,
> +                                             unsigned long size,
> +                                             struct stack_info *info)
> +{
> +       if (info)
> +               info->type = STACK_TYPE_UNKNOWN;
> +
> +       /*
> +        * Both the kernel and nvhe hypervisor make use of
> +        * an overflow_stack
> +        */
> +       return on_overflow_stack(sp, size, info);
> +}
> +
>  static inline void unwind_init_common(struct unwind_state *state,
>                                       struct task_struct *task)
>  {
> --
> 2.37.0.170.g444d1eabd0-goog
>