From 5a8a076506af03f83f83d80412a7c0b06b687ee1 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Mon, 24 Feb 2020 10:21:00 -0600 Subject: crypto: Replace zero-length array with flexible-array member MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] 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 Reviewed-by: Horia Geantă Signed-off-by: Herbert Xu --- drivers/crypto/caam/caamalg.c | 2 +- drivers/crypto/caam/caamalg_qi.c | 4 ++-- drivers/crypto/caam/caamalg_qi2.h | 6 +++--- drivers/crypto/caam/caamhash.c | 2 +- 4 files changed, 7 insertions(+), 7 deletions(-) (limited to 'drivers/crypto/caam') diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c index 03797f9b1050..b7bb7c30adeb 100644 --- a/drivers/crypto/caam/caamalg.c +++ b/drivers/crypto/caam/caamalg.c @@ -909,7 +909,7 @@ struct skcipher_edesc { bool bklog; dma_addr_t sec4_sg_dma; struct sec4_sg_entry *sec4_sg; - u32 hw_desc[0]; + u32 hw_desc[]; }; static void caam_unmap(struct device *dev, struct scatterlist *src, diff --git a/drivers/crypto/caam/caamalg_qi.c b/drivers/crypto/caam/caamalg_qi.c index 4a29e0ef9d63..27e36bdf6163 100644 --- a/drivers/crypto/caam/caamalg_qi.c +++ b/drivers/crypto/caam/caamalg_qi.c @@ -783,7 +783,7 @@ struct aead_edesc { unsigned int assoclen; dma_addr_t assoclen_dma; struct caam_drv_req drv_req; - struct qm_sg_entry sgt[0]; + struct qm_sg_entry sgt[]; }; /* @@ -803,7 +803,7 @@ struct skcipher_edesc { int qm_sg_bytes; dma_addr_t qm_sg_dma; struct caam_drv_req drv_req; - struct qm_sg_entry sgt[0]; + struct qm_sg_entry sgt[]; }; static struct caam_drv_ctx *get_drv_ctx(struct caam_ctx *ctx, diff --git a/drivers/crypto/caam/caamalg_qi2.h b/drivers/crypto/caam/caamalg_qi2.h index 706736776b47..f29cb7bd7dd3 100644 --- a/drivers/crypto/caam/caamalg_qi2.h +++ b/drivers/crypto/caam/caamalg_qi2.h @@ -114,7 +114,7 @@ struct aead_edesc { dma_addr_t qm_sg_dma; unsigned int assoclen; dma_addr_t assoclen_dma; - struct dpaa2_sg_entry sgt[0]; + struct dpaa2_sg_entry sgt[]; }; /* @@ -132,7 +132,7 @@ struct skcipher_edesc { dma_addr_t iv_dma; int qm_sg_bytes; dma_addr_t qm_sg_dma; - struct dpaa2_sg_entry sgt[0]; + struct dpaa2_sg_entry sgt[]; }; /* @@ -146,7 +146,7 @@ struct ahash_edesc { dma_addr_t qm_sg_dma; int src_nents; int qm_sg_bytes; - struct dpaa2_sg_entry sgt[0]; + struct dpaa2_sg_entry sgt[]; }; /** diff --git a/drivers/crypto/caam/caamhash.c b/drivers/crypto/caam/caamhash.c index 2fe852853d40..943bc0296267 100644 --- a/drivers/crypto/caam/caamhash.c +++ b/drivers/crypto/caam/caamhash.c @@ -536,7 +536,7 @@ struct ahash_edesc { int sec4_sg_bytes; bool bklog; u32 hw_desc[DESC_JOB_IO_LEN_MAX / sizeof(u32)] ____cacheline_aligned; - struct sec4_sg_entry sec4_sg[0]; + struct sec4_sg_entry sec4_sg[]; }; static inline void ahash_unmap(struct device *dev, -- cgit v1.2.3