From: Gustavo A. R. Silva Date: Tue, 7 Apr 2020 03:09:57 +0000 (-0700) Subject: lib/bch.c: replace zero-length array with flexible-array member X-Git-Tag: locking-urgent-2020-04-12~11^2~47 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=a44ce5137026493b3bec3768cff92861dbeede5c;p=users%2Fdwmw2%2Flinux.git lib/bch.c: 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 Signed-off-by: Andrew Morton Link: http://lkml.kernel.org/r/20200211205119.GA21234@embeddedor Signed-off-by: Linus Torvalds --- diff --git a/lib/bch.c b/lib/bch.c index 5db6d3a4c8a6f..052d3fb753a08 100644 --- a/lib/bch.c +++ b/lib/bch.c @@ -102,7 +102,7 @@ */ struct gf_poly { unsigned int deg; /* polynomial degree */ - unsigned int c[0]; /* polynomial terms */ + unsigned int c[]; /* polynomial terms */ }; /* given its degree, compute a polynomial size in bytes */