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authorGustavo A. R. Silva <gustavo@embeddedor.com>2020-02-27 00:20:00 +0300
committerDavid S. Miller <davem@davemloft.net>2020-02-27 23:06:20 +0300
commitda60fbe7ef942d64b4d80e99cc9b0205db5964b9 (patch)
treeec1ffd9f3659a9ded8c02d4c3111364d8677b5d2 /drivers/nfc/st21nfca
parent6dd7f1a1fe20222d152875935f3ee0a009342ade (diff)
downloadlinux-da60fbe7ef942d64b4d80e99cc9b0205db5964b9.tar.xz
NFC: 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") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/nfc/st21nfca')
-rw-r--r--drivers/nfc/st21nfca/dep.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/nfc/st21nfca/dep.c b/drivers/nfc/st21nfca/dep.c
index 60acdfd1cb8c..a1d69f9b2d4a 100644
--- a/drivers/nfc/st21nfca/dep.c
+++ b/drivers/nfc/st21nfca/dep.c
@@ -66,7 +66,7 @@ struct st21nfca_atr_req {
u8 bsi;
u8 bri;
u8 ppi;
- u8 gbi[0];
+ u8 gbi[];
} __packed;
struct st21nfca_atr_res {
@@ -79,7 +79,7 @@ struct st21nfca_atr_res {
u8 bri;
u8 to;
u8 ppi;
- u8 gbi[0];
+ u8 gbi[];
} __packed;
struct st21nfca_psl_req {