[PATCH] [next] pcmcia: synclink_cs: replace 1-element array with flex-array member

From: Paulo Miguel Almeida
Date: Wed Dec 14 2022 - 03:42:14 EST


One-element arrays are deprecated, and we are replacing them with
flexible array members instead. So, replace one-element array with
flexible-array member in struct RXBUF and refactor the rest of the code
accordingly.

It's worth mentioning that doing a build before/after this patch
results in no binary output differences.

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].

Link: https://github.com/KSPP/linux/issues/79
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101836 [1]

Signed-off-by: Paulo Miguel Almeida <paulo.miguel.almeida.rodenas@xxxxxxxxx>
---
drivers/char/pcmcia/synclink_cs.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/char/pcmcia/synclink_cs.c b/drivers/char/pcmcia/synclink_cs.c
index b2735be81ab2..1ab2d552f498 100644
--- a/drivers/char/pcmcia/synclink_cs.c
+++ b/drivers/char/pcmcia/synclink_cs.c
@@ -105,7 +105,7 @@ static MGSL_PARAMS default_params = {
typedef struct {
int count;
unsigned char status;
- char data[1];
+ char data[];
} RXBUF;

/* The queue of BH actions to be performed */
@@ -2611,7 +2611,8 @@ static int mgslpc_proc_show(struct seq_file *m, void *v)
static int rx_alloc_buffers(MGSLPC_INFO *info)
{
/* each buffer has header and data */
- info->rx_buf_size = sizeof(RXBUF) + info->max_frame_size;
+ info->rx_buf_size = max(offsetof(typeof(RXBUF), data) + 1, sizeof(RXBUF))
+ + info->max_frame_size;

/* calculate total allocation size for 8 buffers */
info->rx_buf_total_size = info->rx_buf_size * 8;
--
2.38.1