Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <feeb18db-2d7f-5e3b-bc28-57291e2d4255@quicinc.com>
Date:   Thu, 25 May 2023 16:50:59 +0530
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.11.0
Subject: Re: [PATCH][next] media: venus: Replace one-element arrays with
 flexible-array members
Content-Language: en-US
To:     "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        Stanimir Varbanov <stanimir.k.varbanov@gmail.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>
CC:     <linux-media@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-hardening@vger.kernel.org>
References: <ZGPk3PpvYzjD1+0/@work>
From:   Vikash Garodia <quic_vgarodia@quicinc.com>
In-Reply-To: <ZGPk3PpvYzjD1+0/@work>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 5/17/2023 1:47 AM, Gustavo A. R. Silva wrote:
> One-element arrays are deprecated, and we are replacing them with flexible
> array members instead. So, replace one-element arrays with flexible-array
> members in multiple structures, and refactor the rest of the code,
> accordingly.
> 
> This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
> routines on memcpy() and help us make progress towards globally
> enabling -fstrict-flex-arrays=3 [1].
> 
> This results in no differences in binary output.
> 
> Link: https://github.com/KSPP/linux/issues/79
> Link: https://github.com/KSPP/linux/issues/291
> Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

The patch looks good to me. It would be nice if we can combine all the patches
related to flexible array handling in video driver in a single patch series. At
the moment, there are multiple patches with similar subject.

> ---
>  drivers/media/platform/qcom/venus/hfi_msgs.c |  4 ++--
>  drivers/media/platform/qcom/venus/hfi_msgs.h | 14 +++++++-------
>  2 files changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/venus/hfi_msgs.c b/drivers/media/platform/qcom/venus/hfi_msgs.c
> index df96db3761a7..6efd78606d9b 100644
> --- a/drivers/media/platform/qcom/venus/hfi_msgs.c
> +++ b/drivers/media/platform/qcom/venus/hfi_msgs.c
> @@ -233,7 +233,7 @@ static void hfi_sys_init_done(struct venus_core *core, struct venus_inst *inst,
>  		goto done;
>  	}
>  
> -	rem_bytes = pkt->hdr.size - sizeof(*pkt) + sizeof(u32);
> +	rem_bytes = pkt->hdr.size - sizeof(*pkt);
>  	if (rem_bytes <= 0) {
>  		/* missing property data */
>  		error = HFI_ERR_SYS_INSUFFICIENT_RESOURCES;
> @@ -434,7 +434,7 @@ static void hfi_session_init_done(struct venus_core *core,
>  	if (!IS_V1(core))
>  		goto done;
>  
> -	rem_bytes = pkt->shdr.hdr.size - sizeof(*pkt) + sizeof(u32);
> +	rem_bytes = pkt->shdr.hdr.size - sizeof(*pkt);
>  	if (rem_bytes <= 0) {
>  		error = HFI_ERR_SESSION_INSUFFICIENT_RESOURCES;
>  		goto done;
> diff --git a/drivers/media/platform/qcom/venus/hfi_msgs.h b/drivers/media/platform/qcom/venus/hfi_msgs.h
> index 510513697335..8c2e17b0d36f 100644
> --- a/drivers/media/platform/qcom/venus/hfi_msgs.h
> +++ b/drivers/media/platform/qcom/venus/hfi_msgs.h
> @@ -50,7 +50,7 @@ struct hfi_msg_event_notify_pkt {
>  	u32 event_id;
>  	u32 event_data1;
>  	u32 event_data2;
> -	u32 ext_event_data[1];
> +	u32 ext_event_data[];
>  };
>  
>  struct hfi_msg_event_release_buffer_ref_pkt {
> @@ -63,7 +63,7 @@ struct hfi_msg_sys_init_done_pkt {
>  	struct hfi_pkt_hdr hdr;
>  	u32 error_type;
>  	u32 num_properties;
> -	u32 data[1];
> +	u32 data[];
>  };
>  
>  struct hfi_msg_sys_pc_prep_done_pkt {
> @@ -81,7 +81,7 @@ struct hfi_msg_session_init_done_pkt {
>  	struct hfi_session_hdr_pkt shdr;
>  	u32 error_type;
>  	u32 num_properties;
> -	u32 data[1];
> +	u32 data[];
>  };
>  
>  struct hfi_msg_session_end_done_pkt {
> @@ -228,7 +228,7 @@ struct hfi_msg_session_parse_sequence_header_done_pkt {
>  	struct hfi_session_hdr_pkt shdr;
>  	u32 error_type;
>  	u32 num_properties;
> -	u32 data[1];
> +	u32 data[];
>  };
>  
>  struct hfi_msg_session_property_info_pkt {
> @@ -247,7 +247,7 @@ struct hfi_msg_session_release_buffers_done_pkt {
>  	struct hfi_session_hdr_pkt shdr;
>  	u32 error_type;
>  	u32 num_buffers;
> -	u32 buffer_info[1];
> +	u32 buffer_info[];
>  };
>  
>  struct hfi_msg_sys_debug_pkt {
> @@ -256,7 +256,7 @@ struct hfi_msg_sys_debug_pkt {
>  	u32 msg_size;
>  	u32 time_stamp_hi;
>  	u32 time_stamp_lo;
> -	u8 msg_data[1];
> +	u8 msg_data[];
>  };
>  
>  struct hfi_msg_sys_coverage_pkt {
> @@ -264,7 +264,7 @@ struct hfi_msg_sys_coverage_pkt {
>  	u32 msg_size;
>  	u32 time_stamp_hi;
>  	u32 time_stamp_lo;
> -	u8 msg_data[1];
> +	u8 msg_data[];
>  };
>  
>  struct venus_core;