From 539db76293cd2e73fe798ed0f21ac852351fedd8 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Tue, 11 Feb 2020 17:16:04 -0600 Subject: firmware: arm_scpi: Replace zero-length array with flexible-array member The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertenly introduced[3] to the codebase from now on. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Replace the zero-length member "payload" in {legacy_,}scpi_shared_mem structures with flexible-array. Link: https://lore.kernel.org/r/20200211231604.GA17274@embeddedor Signed-off-by: Gustavo A. R. Silva Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scpi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/arm_scpi.c b/drivers/firmware/arm_scpi.c index a80c331c3a6e..d0dee37ad522 100644 --- a/drivers/firmware/arm_scpi.c +++ b/drivers/firmware/arm_scpi.c @@ -262,12 +262,12 @@ struct scpi_drvinfo { struct scpi_shared_mem { __le32 command; __le32 status; - u8 payload[0]; + u8 payload[]; } __packed; struct legacy_scpi_shared_mem { __le32 status; - u8 payload[0]; + u8 payload[]; } __packed; struct scp_capabilities { -- cgit v1.2.3