From fa226f1d81e2d3798d30eaa14550d7f35c35e6f3 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Fri, 21 Feb 2020 09:06:12 -0600 Subject: s390: 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 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") Link: https://lkml.kernel.org/r/20200221150612.GA9717@embeddedor Signed-off-by: Gustavo A. R. Silva Signed-off-by: Vasily Gorbik --- drivers/s390/crypto/pkey_api.c | 2 +- drivers/s390/crypto/zcrypt_ccamisc.h | 2 +- drivers/s390/crypto/zcrypt_msgtype6.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/s390/crypto') diff --git a/drivers/s390/crypto/pkey_api.c b/drivers/s390/crypto/pkey_api.c index 2f33c5fcf676..74e63ec49068 100644 --- a/drivers/s390/crypto/pkey_api.c +++ b/drivers/s390/crypto/pkey_api.c @@ -80,7 +80,7 @@ struct clearaeskeytoken { u8 res1[3]; u32 keytype; /* key type, one of the PKEY_KEYTYPE values */ u32 len; /* bytes actually stored in clearkey[] */ - u8 clearkey[0]; /* clear key value */ + u8 clearkey[]; /* clear key value */ } __packed; /* diff --git a/drivers/s390/crypto/zcrypt_ccamisc.h b/drivers/s390/crypto/zcrypt_ccamisc.h index 3a9876d5ab0e..8b7a641671c9 100644 --- a/drivers/s390/crypto/zcrypt_ccamisc.h +++ b/drivers/s390/crypto/zcrypt_ccamisc.h @@ -90,7 +90,7 @@ struct cipherkeytoken { u16 kmf1; /* key management field 1 */ u16 kmf2; /* key management field 2 */ u16 kmf3; /* key management field 3 */ - u8 vdata[0]; /* variable part data follows */ + u8 vdata[]; /* variable part data follows */ } __packed; /* Some defines for the CCA AES cipherkeytoken kmf1 field */ diff --git a/drivers/s390/crypto/zcrypt_msgtype6.c b/drivers/s390/crypto/zcrypt_msgtype6.c index a36251d138fb..eadd3a438a4b 100644 --- a/drivers/s390/crypto/zcrypt_msgtype6.c +++ b/drivers/s390/crypto/zcrypt_msgtype6.c @@ -590,7 +590,7 @@ struct type86x_reply { struct CPRBX cprbx; unsigned char pad[4]; /* 4 byte function code/rules block ? */ unsigned short length; - char text[0]; + char text[]; } __packed; struct type86_ep11_reply { -- cgit v1.2.3