2023-05-24 02:14:07

by Gustavo A. R. Silva

[permalink] [raw]
Subject: [PATCH][next] wifi: rtw89: coex: Fix __write_overflow_field error

One-element arrays as fake flexible arrays are deprecated, and we are
moving towards adopting C99 flexible-array members instead.

Fix the following error seen under GCC-13 and -fstrict-flex-arrays=3:
In function ‘fortify_memcpy_chk’,
inlined from ‘_append_tdma’ at drivers/net/wireless/realtek/rtw89/coex.c:1579:3:
include/linux/fortify-string.h:583:25: error: call to ‘__write_overflow_field’ declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
583 | __write_overflow_field(p_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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/21
Link: https://github.com/KSPP/linux/issues/299
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/net/wireless/realtek/rtw89/coex.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtw89/coex.c b/drivers/net/wireless/realtek/rtw89/coex.c
index 3a586a971e8f..bda0e1e99a8c 100644
--- a/drivers/net/wireless/realtek/rtw89/coex.c
+++ b/drivers/net/wireless/realtek/rtw89/coex.c
@@ -206,7 +206,7 @@ static const struct rtw89_btc_ver rtw89_btc_ver_defs[] = {
struct rtw89_btc_btf_tlv {
u8 type;
u8 len;
- u8 val[1];
+ u8 val[];
} __packed;

enum btc_btf_set_report_en {
--
2.34.1



2023-05-24 02:26:21

by Ping-Ke Shih

[permalink] [raw]
Subject: RE: [PATCH][next] wifi: rtw89: coex: Fix __write_overflow_field error



> -----Original Message-----
> From: Gustavo A. R. Silva <[email protected]>
> Sent: Wednesday, May 24, 2023 10:13 AM
> To: Ping-Ke Shih <[email protected]>; Kalle Valo <[email protected]>
> Cc: [email protected]; [email protected]; Gustavo A. R. Silva
> <[email protected]>; [email protected]
> Subject: [PATCH][next] wifi: rtw89: coex: Fix __write_overflow_field error
>
> One-element arrays as fake flexible arrays are deprecated, and we are
> moving towards adopting C99 flexible-array members instead.
>
> Fix the following error seen under GCC-13 and -fstrict-flex-arrays=3:
> In function ‘fortify_memcpy_chk’,
> inlined from ‘_append_tdma’ at drivers/net/wireless/realtek/rtw89/coex.c:1579:3:
> include/linux/fortify-string.h:583:25: error: call to ‘__write_overflow_field’ declared with attribute
> warning: detected write beyond size of field (1st parameter); maybe use struct_group()?
> [-Werror=attribute-warning]
> 583 | __write_overflow_field(p_size_field, size);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> 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/21
> Link: https://github.com/KSPP/linux/issues/299
> Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> drivers/net/wireless/realtek/rtw89/coex.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/realtek/rtw89/coex.c b/drivers/net/wireless/realtek/rtw89/coex.c
> index 3a586a971e8f..bda0e1e99a8c 100644
> --- a/drivers/net/wireless/realtek/rtw89/coex.c
> +++ b/drivers/net/wireless/realtek/rtw89/coex.c
> @@ -206,7 +206,7 @@ static const struct rtw89_btc_ver rtw89_btc_ver_defs[] = {
> struct rtw89_btc_btf_tlv {
> u8 type;
> u8 len;
> - u8 val[1];
> + u8 val[];
> } __packed;
>
> enum btc_btf_set_report_en {

Arnd has sent the same patch [1] as yours.

[1] https://lore.kernel.org/linux-wireless/[email protected]/T/#mca619c8261b87b88eedd391ceafb34c40d513ce5

2023-05-24 02:38:01

by Gustavo A. R. Silva

[permalink] [raw]
Subject: Re: [PATCH][next] wifi: rtw89: coex: Fix __write_overflow_field error



On 5/23/23 20:21, Ping-Ke Shih wrote:
>
>
>> -----Original Message-----
>> From: Gustavo A. R. Silva <[email protected]>
>> Sent: Wednesday, May 24, 2023 10:13 AM
>> To: Ping-Ke Shih <[email protected]>; Kalle Valo <[email protected]>
>> Cc: [email protected]; [email protected]; Gustavo A. R. Silva
>> <[email protected]>; [email protected]
>> Subject: [PATCH][next] wifi: rtw89: coex: Fix __write_overflow_field error
>>
>> One-element arrays as fake flexible arrays are deprecated, and we are
>> moving towards adopting C99 flexible-array members instead.
>>
>> Fix the following error seen under GCC-13 and -fstrict-flex-arrays=3:
>> In function ‘fortify_memcpy_chk’,
>> inlined from ‘_append_tdma’ at drivers/net/wireless/realtek/rtw89/coex.c:1579:3:
>> include/linux/fortify-string.h:583:25: error: call to ‘__write_overflow_field’ declared with attribute
>> warning: detected write beyond size of field (1st parameter); maybe use struct_group()?
>> [-Werror=attribute-warning]
>> 583 | __write_overflow_field(p_size_field, size);
>> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> 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/21
>> Link: https://github.com/KSPP/linux/issues/299
>> Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>> ---
>> drivers/net/wireless/realtek/rtw89/coex.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/wireless/realtek/rtw89/coex.c b/drivers/net/wireless/realtek/rtw89/coex.c
>> index 3a586a971e8f..bda0e1e99a8c 100644
>> --- a/drivers/net/wireless/realtek/rtw89/coex.c
>> +++ b/drivers/net/wireless/realtek/rtw89/coex.c
>> @@ -206,7 +206,7 @@ static const struct rtw89_btc_ver rtw89_btc_ver_defs[] = {
>> struct rtw89_btc_btf_tlv {
>> u8 type;
>> u8 len;
>> - u8 val[1];
>> + u8 val[];
>> } __packed;
>>
>> enum btc_btf_set_report_en {
>
> Arnd has sent the same patch [1] as yours.

Oh that's great! What a coincidence. :)

Thanks for letting me know.
--
Gustavo

>
> [1] https://lore.kernel.org/linux-wireless/[email protected]/T/#mca619c8261b87b88eedd391ceafb34c40d513ce5
>