[PATCH] crypto: Replace zero-length array with flexible-array member
From: Gustavo A. R. Silva <hidden>
Date: 2020-02-24 16:18:16
Also in:
linux-arm-kernel, linux-mediatek, linuxppc-dev, lkml
Subsystem:
crypto api, freescale caam (cryptographic acceleration and assurance module) driver, ibm power in-nest crypto acceleration, linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Herbert Xu, "David S. Miller", Horia Geantă, Pankaj Gupta, Gaurav Jain, Breno Leitão, Nayna Jain, Paulo Flabiano Smorigo, Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
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 <redacted>
---
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 +-
drivers/crypto/cavium/nitrox/nitrox_main.c | 2 +-
drivers/crypto/chelsio/chcr_core.h | 2 +-
drivers/crypto/mediatek/mtk-sha.c | 2 +-
drivers/crypto/nx/nx.h | 2 +-
drivers/crypto/omap-sham.c | 4 ++--
include/crypto/if_alg.h | 2 +-
10 files changed, 14 insertions(+), 14 deletions(-)
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,
diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
index c4632d84c9a1..e91be9b8b083 100644
--- a/drivers/crypto/cavium/nitrox/nitrox_main.c
+++ b/drivers/crypto/cavium/nitrox/nitrox_main.c@@ -71,7 +71,7 @@ struct ucode { char version[VERSION_LEN - 1]; __be32 code_size; u8 raz[12]; - u64 code[0]; + u64 code[]; }; /**
diff --git a/drivers/crypto/chelsio/chcr_core.h b/drivers/crypto/chelsio/chcr_core.h
index b41ef1abfe74..e480096754b5 100644
--- a/drivers/crypto/chelsio/chcr_core.h
+++ b/drivers/crypto/chelsio/chcr_core.h@@ -68,7 +68,7 @@ struct _key_ctx { __be32 ctx_hdr; u8 salt[MAX_SALT]; __be64 iv_to_auth; - unsigned char key[0]; + unsigned char key[]; }; #define KEYCTX_TX_WR_IV_S 55
diff --git a/drivers/crypto/mediatek/mtk-sha.c b/drivers/crypto/mediatek/mtk-sha.c
index 9e9f48bb7f85..bd6309e57ab8 100644
--- a/drivers/crypto/mediatek/mtk-sha.c
+++ b/drivers/crypto/mediatek/mtk-sha.c@@ -107,7 +107,7 @@ struct mtk_sha_ctx { u8 id; u8 buf[SHA_BUF_SIZE] __aligned(sizeof(u32)); - struct mtk_sha_hmac_ctx base[0]; + struct mtk_sha_hmac_ctx base[]; }; struct mtk_sha_drv {
diff --git a/drivers/crypto/nx/nx.h b/drivers/crypto/nx/nx.h
index 91c54289124a..c6233173c612 100644
--- a/drivers/crypto/nx/nx.h
+++ b/drivers/crypto/nx/nx.h@@ -37,7 +37,7 @@ struct max_sync_cop { u32 fc; u32 mode; u32 triplets; - struct msc_triplet trip[0]; + struct msc_triplet trip[]; } __packed; struct alg_props {
diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c
index 4f915a4ef5b0..e4072cd38585 100644
--- a/drivers/crypto/omap-sham.c
+++ b/drivers/crypto/omap-sham.c@@ -159,7 +159,7 @@ struct omap_sham_reqctx { int sg_len; unsigned int total; /* total request */ - u8 buffer[0] OMAP_ALIGNED; + u8 buffer[] OMAP_ALIGNED; }; struct omap_sham_hmac_ctx {
@@ -176,7 +176,7 @@ struct omap_sham_ctx { /* fallback stuff */ struct crypto_shash *fallback; - struct omap_sham_hmac_ctx base[0]; + struct omap_sham_hmac_ctx base[]; }; #define OMAP_SHAM_QUEUE_LENGTH 10
diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
index 24cfa96f98ea..56527c85d122 100644
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h@@ -66,7 +66,7 @@ struct af_alg_sgl { struct af_alg_tsgl { struct list_head list; unsigned int cur; /* Last processed SG entry */ - struct scatterlist sg[0]; /* Array of SGs forming the SGL */ + struct scatterlist sg[]; /* Array of SGs forming the SGL */ }; #define MAX_SGL_ENTS ((4096 - sizeof(struct af_alg_tsgl)) / \
--
2.25.0