tree 1375baa82013bb5682221c03ded10d6f934b8890
parent 78d593615c6f1cd10232a34899af93d5d2696c30
author Gustavo A. R. Silva <gustavoars@kernel.org> 1612582601 -0600
committer Gustavo A. R. Silva <gustavoars@kernel.org> 1612582700 -0600

media: siano: Replace one-element array with flexible-array in struct sms_msg_data

There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].

Refactor the code according to the use of a flexible-array member in
struct sms_msg_data, instead of a one-element array.

Also, this helps with the ongoing efforts to enable -Warray-bounds and
fix the following warnings:

  CC [M]  drivers/media/common/siano/smscoreapi.o
drivers/media/common/siano/smscoreapi.c: In function ‘smscore_load_firmware_family2’:
drivers/media/common/siano/smscoreapi.c:1003:24: warning: array subscript 1 is above array bounds of ‘u32[1]’ {aka ‘unsigned int[1]’} [-Warray-bounds]
 1003 |   trigger_msg->msg_data[1] = 6; /* Priority */
      |   ~~~~~~~~~~~~~~~~~~~~~^~~
drivers/media/common/siano/smscoreapi.c:1004:24: warning: array subscript 2 is above array bounds of ‘u32[1]’ {aka ‘unsigned int[1]’} [-Warray-bounds]
 1004 |   trigger_msg->msg_data[2] = 0x200; /* Stack size */
      |   ~~~~~~~~~~~~~~~~~~~~~^~~
drivers/media/common/siano/smscoreapi.c:1005:24: warning: array subscript 3 is above array bounds of ‘u32[1]’ {aka ‘unsigned int[1]’} [-Warray-bounds]
 1005 |   trigger_msg->msg_data[3] = 0; /* Parameter */
      |   ~~~~~~~~~~~~~~~~~~~~~^~~
drivers/media/common/siano/smscoreapi.c:1006:24: warning: array subscript 4 is above array bounds of ‘u32[1]’ {aka ‘unsigned int[1]’} [-Warray-bounds]
 1006 |   trigger_msg->msg_data[4] = 4; /* Task ID */
      |   ~~~~~~~~~~~~~~~~~~~~~^~~

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/109
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>