Gustavo A. R. Silva
2020-Feb-11 22:29 UTC
[PATCH] char: virtio: 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") Signed-off-by: Gustavo A. R. Silva <gustavo at embeddedor.com> --- drivers/char/virtio_console.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index fbeb71953526..a136239e4c14 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -125,7 +125,7 @@ struct port_buffer { unsigned int sgpages; /* sg is used if spages > 0. sg must be the last in is struct */ - struct scatterlist sg[0]; + struct scatterlist sg[]; }; /* -- 2.25.0
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