2023-05-16 23:15:42

by Gustavo A. R. Silva

Subject: [PATCH 1/2][next] media: venus: hfi_cmds: Replace one-element array with flexible-array member

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 struct hfi_session_set_buffers_pkt, 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/292
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/media/platform/qcom/venus/hfi_cmds.c | 12 ++++++------
drivers/media/platform/qcom/venus/hfi_cmds.h | 2 +-
2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/media/platform/qcom/venus/hfi_cmds.c b/drivers/media/platform/qcom/venus/hfi_cmds.c
index bc3f8ff05840..21d1b3c90dc0 100644
--- a/drivers/media/platform/qcom/venus/hfi_cmds.c
+++ b/drivers/media/platform/qcom/venus/hfi_cmds.c
@@ -200,8 +200,8 @@ int pkt_session_set_buffers(struct hfi_session_set_buffers_pkt *pkt,
struct hfi_buffer_info *bi;

pkt->extradata_size = bd->extradata_size;
- pkt->shdr.hdr.size = sizeof(*pkt) - sizeof(u32) +
- (bd->num_buffers * sizeof(*bi));
+ pkt->shdr.hdr.size = sizeof(*pkt) +
+ bd->num_buffers * sizeof(*bi);
bi = (struct hfi_buffer_info *)pkt->buffer_info;
for (i = 0; i < pkt->num_buffers; i++) {
bi->buffer_addr = bd->device_addr;
@@ -210,7 +210,7 @@ int pkt_session_set_buffers(struct hfi_session_set_buffers_pkt *pkt,
} else {
pkt->extradata_size = 0;
pkt->shdr.hdr.size = sizeof(*pkt) +
- ((bd->num_buffers - 1) * sizeof(u32));
+ bd->num_buffers * sizeof(u32);
for (i = 0; i < pkt->num_buffers; i++)
pkt->buffer_info[i] = bd->device_addr;
}
@@ -243,8 +243,8 @@ int pkt_session_unset_buffers(struct hfi_session_release_buffer_pkt *pkt,
bi->extradata_addr = bd->extradata_addr;
}
pkt->shdr.hdr.size =
- sizeof(struct hfi_session_set_buffers_pkt) -
- sizeof(u32) + (bd->num_buffers * sizeof(*bi));
+ sizeof(struct hfi_session_set_buffers_pkt) +
+ bd->num_buffers * sizeof(*bi);
} else {
for (i = 0; i < pkt->num_buffers; i++)
pkt->buffer_info[i] = bd->device_addr;
@@ -252,7 +252,7 @@ int pkt_session_unset_buffers(struct hfi_session_release_buffer_pkt *pkt,
pkt->extradata_size = 0;
pkt->shdr.hdr.size =
sizeof(struct hfi_session_set_buffers_pkt) +
- ((bd->num_buffers - 1) * sizeof(u32));
+ bd->num_buffers * sizeof(u32);
}

pkt->response_req = bd->response_required;
diff --git a/drivers/media/platform/qcom/venus/hfi_cmds.h b/drivers/media/platform/qcom/venus/hfi_cmds.h
index 99bc0b6db67c..ba74d03eb9cd 100644
--- a/drivers/media/platform/qcom/venus/hfi_cmds.h
+++ b/drivers/media/platform/qcom/venus/hfi_cmds.h
@@ -117,7 +117,7 @@ struct hfi_session_set_buffers_pkt {
u32 extradata_size;
u32 min_buffer_size;
u32 num_buffers;
- u32 buffer_info[1];
+ u32 buffer_info[];
};

struct hfi_session_get_sequence_header_pkt {
--
2.34.1

2023-05-17 19:13:42

by Kees Cook

Subject: Re: [PATCH 1/2][next] media: venus: hfi_cmds: Replace one-element array with flexible-array member

On Tue, May 16, 2023 at 05:14:27PM -0600, 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 struct hfi_session_set_buffers_pkt, 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/292
> Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
> Signed-off-by: Gustavo A. R. Silva <[email protected]>

Reviewed-by: Kees Cook <[email protected]>

--
Kees Cook

2023-05-25 11:55:56

by Vikash Garodia

Subject: Re: [PATCH 1/2][next] media: venus: hfi_cmds: Replace one-element array with flexible-array member

On 5/17/2023 4:44 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 struct hfi_session_set_buffers_pkt, 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/292
> Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
> Signed-off-by: Gustavo A. R. Silva <[email protected]>

The patch looks good. As stated in previous patch, lets combine this into a
single series.

> ---
> drivers/media/platform/qcom/venus/hfi_cmds.c | 12 ++++++------
> drivers/media/platform/qcom/venus/hfi_cmds.h | 2 +-
> 2 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/media/platform/qcom/venus/hfi_cmds.c b/drivers/media/platform/qcom/venus/hfi_cmds.c
> index bc3f8ff05840..21d1b3c90dc0 100644
> --- a/drivers/media/platform/qcom/venus/hfi_cmds.c
> +++ b/drivers/media/platform/qcom/venus/hfi_cmds.c
> @@ -200,8 +200,8 @@ int pkt_session_set_buffers(struct hfi_session_set_buffers_pkt *pkt,
> struct hfi_buffer_info *bi;
>
> pkt->extradata_size = bd->extradata_size;
> - pkt->shdr.hdr.size = sizeof(*pkt) - sizeof(u32) +
> - (bd->num_buffers * sizeof(*bi));
> + pkt->shdr.hdr.size = sizeof(*pkt) +
> + bd->num_buffers * sizeof(*bi);
> bi = (struct hfi_buffer_info *)pkt->buffer_info;
> for (i = 0; i < pkt->num_buffers; i++) {
> bi->buffer_addr = bd->device_addr;
> @@ -210,7 +210,7 @@ int pkt_session_set_buffers(struct hfi_session_set_buffers_pkt *pkt,
> } else {
> pkt->extradata_size = 0;
> pkt->shdr.hdr.size = sizeof(*pkt) +
> - ((bd->num_buffers - 1) * sizeof(u32));
> + bd->num_buffers * sizeof(u32);
> for (i = 0; i < pkt->num_buffers; i++)
> pkt->buffer_info[i] = bd->device_addr;
> }
> @@ -243,8 +243,8 @@ int pkt_session_unset_buffers(struct hfi_session_release_buffer_pkt *pkt,
> bi->extradata_addr = bd->extradata_addr;
> }
> pkt->shdr.hdr.size =
> - sizeof(struct hfi_session_set_buffers_pkt) -
> - sizeof(u32) + (bd->num_buffers * sizeof(*bi));
> + sizeof(struct hfi_session_set_buffers_pkt) +
> + bd->num_buffers * sizeof(*bi);
> } else {
> for (i = 0; i < pkt->num_buffers; i++)
> pkt->buffer_info[i] = bd->device_addr;
> @@ -252,7 +252,7 @@ int pkt_session_unset_buffers(struct hfi_session_release_buffer_pkt *pkt,
> pkt->extradata_size = 0;
> pkt->shdr.hdr.size =
> sizeof(struct hfi_session_set_buffers_pkt) +
> - ((bd->num_buffers - 1) * sizeof(u32));
> + bd->num_buffers * sizeof(u32);
> }
>
> pkt->response_req = bd->response_required;
> diff --git a/drivers/media/platform/qcom/venus/hfi_cmds.h b/drivers/media/platform/qcom/venus/hfi_cmds.h
> index 99bc0b6db67c..ba74d03eb9cd 100644
> --- a/drivers/media/platform/qcom/venus/hfi_cmds.h
> +++ b/drivers/media/platform/qcom/venus/hfi_cmds.h
> @@ -117,7 +117,7 @@ struct hfi_session_set_buffers_pkt {
> u32 extradata_size;
> u32 min_buffer_size;
> u32 num_buffers;
> - u32 buffer_info[1];
> + u32 buffer_info[];
> };
>
> struct hfi_session_get_sequence_header_pkt {