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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-21 09:06:12 -0600 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2020-02-27 16:02:21 +0100 |
| commit | fa226f1d81e2d3798d30eaa14550d7f35c35e6f3 (patch) | |
| tree | 2063b7d5c04db419fe443d7a2aa39e1cc21cbe4e /drivers/s390/crypto | |
| parent | d5d006fa0927c34fa083c8d48e33b1c30b29fd1b (diff) | |
| download | linux-fa226f1d81e2d3798d30eaa14550d7f35c35e6f3.tar.gz | |
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 <gustavo@embeddedor.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'drivers/s390/crypto')
| -rw-r--r-- | drivers/s390/crypto/pkey_api.c | 2 | ||||
| -rw-r--r-- | drivers/s390/crypto/zcrypt_ccamisc.h | 2 | ||||
| -rw-r--r-- | drivers/s390/crypto/zcrypt_msgtype6.c | 2 |
3 files changed, 3 insertions, 3 deletions
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 { |