i2c: acpi: Replace zero-length array with DECLARE_FLEX_ARRAY() helper

[PATCH][next] i2c: acpi: Replace zero-length array with DECLARE_FLEX_ARRAY() helper

Posted by Gustavo A. R. Silva 3 years, 6 months ago

Zero-length arrays are deprecated and we are moving towards adopting
C99 flexible-array members, instead. So, replace zero-length arrays
declarations in anonymous union with the new DECLARE_FLEX_ARRAY()
helper macro.

This helper allows for flexible-array members in unions.

Link: https://github.com/KSPP/linux/issues/193
Link: https://github.com/KSPP/linux/issues/218
Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/i2c/i2c-core-acpi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index 08b561f0709d..da6568a20177 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -26,7 +26,7 @@ struct gsb_buffer {
 	union {
 		u16	wdata;
 		u8	bdata;
-		u8	data[0];
+		DECLARE_FLEX_ARRAY(u8, data);
 	};
 } __packed;
 
-- 
2.34.1

Re: [PATCH][next] i2c: acpi: Replace zero-length array with DECLARE_FLEX_ARRAY() helper

Posted by Wolfram Sang 3 years, 6 months ago

On Mon, Sep 26, 2022 at 04:47:25PM -0500, Gustavo A. R. Silva wrote:
> Zero-length arrays are deprecated and we are moving towards adopting
> C99 flexible-array members, instead. So, replace zero-length arrays
> declarations in anonymous union with the new DECLARE_FLEX_ARRAY()
> helper macro.
> 
> This helper allows for flexible-array members in unions.
> 
> Link: https://github.com/KSPP/linux/issues/193
> Link: https://github.com/KSPP/linux/issues/218
> Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Applied to for-next, thanks!

Re: [PATCH][next] i2c: acpi: Replace zero-length array with DECLARE_FLEX_ARRAY() helper

Posted by Kees Cook 3 years, 6 months ago

On Mon, Sep 26, 2022 at 04:47:25PM -0500, Gustavo A. R. Silva wrote:
> Zero-length arrays are deprecated and we are moving towards adopting
> C99 flexible-array members, instead. So, replace zero-length arrays
> declarations in anonymous union with the new DECLARE_FLEX_ARRAY()
> helper macro.
> 
> This helper allows for flexible-array members in unions.
> 
> Link: https://github.com/KSPP/linux/issues/193
> Link: https://github.com/KSPP/linux/issues/218
> Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook