2024-03-26 02:14:42

by Gustavo A. R. Silva

[permalink] [raw]
Subject: [PATCH v2][next] ALSA: firewire-lib: Avoid -Wflex-array-member-not-at-end warning

Use the `DEFINE_FLEX()` helper for an on-stack definition of a
flexible structure where the size of the flexible-array member
is known at compile-time, and refactor the rest of the code,
accordingly.

So, with these changes, fix the following warning:
sound/firewire/amdtp-stream.c:1184:46: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Link: https://github.com/KSPP/linux/issues/202
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
Changes in v2:
- Use DEFINE_FLEX() helper instead of a new tagged struct.

v1:
- Link: https://lore.kernel.org/linux-hardening/d3a764eb76909b16b8a22d9ff530e5edf0e59e6b.1709658886.git.gustavoars@kernel.org/

sound/firewire/amdtp-stream.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index c9f153f85ae6..d35d0a420ee0 100644
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -1180,13 +1180,11 @@ static void process_rx_packets(struct fw_iso_context *context, u32 tstamp, size_
(void)fw_card_read_cycle_time(fw_parent_device(s->unit)->card, &curr_cycle_time);

for (i = 0; i < packets; ++i) {
- struct {
- struct fw_iso_packet params;
- __be32 header[CIP_HEADER_QUADLETS];
- } template = { {0}, {0} };
+ DEFINE_FLEX(struct fw_iso_packet, template, header,
+ header_length, CIP_HEADER_QUADLETS);
bool sched_irq = false;

- build_it_pkt_header(s, desc->cycle, &template.params, pkt_header_length,
+ build_it_pkt_header(s, desc->cycle, template, pkt_header_length,
desc->data_blocks, desc->data_block_counter,
desc->syt, i, curr_cycle_time);

@@ -1198,7 +1196,7 @@ static void process_rx_packets(struct fw_iso_context *context, u32 tstamp, size_
}
}

- if (queue_out_packet(s, &template.params, sched_irq) < 0) {
+ if (queue_out_packet(s, template, sched_irq) < 0) {
cancel_stream(s);
return;
}
--
2.34.1



2024-03-26 04:33:34

by Takashi Sakamoto

[permalink] [raw]
Subject: Re: [PATCH v2][next] ALSA: firewire-lib: Avoid -Wflex-array-member-not-at-end warning

Hi,

On Mon, Mar 25, 2024 at 07:59:34PM -0600, Gustavo A. R. Silva wrote:
> Use the `DEFINE_FLEX()` helper for an on-stack definition of a
> flexible structure where the size of the flexible-array member
> is known at compile-time, and refactor the rest of the code,
> accordingly.
>
> So, with these changes, fix the following warning:
> sound/firewire/amdtp-stream.c:1184:46: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>
> Link: https://github.com/KSPP/linux/issues/202
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> Changes in v2:
> - Use DEFINE_FLEX() helper instead of a new tagged struct.
>
> v1:
> - Link: https://lore.kernel.org/linux-hardening/d3a764eb76909b16b8a22d9ff530e5edf0e59e6b.1709658886.git.gustavoars@kernel.org/
>
> sound/firewire/amdtp-stream.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)

It looks good to me.

Reviewed-by: Takashi Sakamoto <[email protected]>

I remark that the change requires a commit d8e45f2929b9 "overflow: Change
DEFINE_FLEX to take __counted_by member"), added to v6.9-rc1.


Thanks

Takashi Sakamoto

2024-03-26 11:27:29

by Takashi Iwai

[permalink] [raw]
Subject: Re: [PATCH v2][next] ALSA: firewire-lib: Avoid -Wflex-array-member-not-at-end warning

On Tue, 26 Mar 2024 02:59:34 +0100,
Gustavo A. R. Silva wrote:
>
> Use the `DEFINE_FLEX()` helper for an on-stack definition of a
> flexible structure where the size of the flexible-array member
> is known at compile-time, and refactor the rest of the code,
> accordingly.
>
> So, with these changes, fix the following warning:
> sound/firewire/amdtp-stream.c:1184:46: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>
> Link: https://github.com/KSPP/linux/issues/202
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> Changes in v2:
> - Use DEFINE_FLEX() helper instead of a new tagged struct.
>
> v1:
> - Link: https://lore.kernel.org/linux-hardening/d3a764eb76909b16b8a22d9ff530e5edf0e59e6b.1709658886.git.gustavoars@kernel.org/

Applied now. Thanks.


Takashi