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authorGustavo A. R. Silva <gustavo@embeddedor.com>2020-02-14 17:03:12 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2020-02-14 17:19:22 -0800
commit3dbae15538972c9e1578cb216964c2840361a538 (patch)
treeb6d2c378ceca6d49e82f838bc6a0a7120600c4d5
parent94bef5d57992f9e987a9b7e8fa736ee204ac4f7a (diff)
Input: cyapa - 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> Link: https://lore.kernel.org/r/20200214172132.GA28389@embeddedor Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
-rw-r--r--drivers/input/mouse/cyapa_gen5.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/input/mouse/cyapa_gen5.c b/drivers/input/mouse/cyapa_gen5.c
index 14239fbd72cf..7f012bfa2658 100644
--- a/drivers/input/mouse/cyapa_gen5.c
+++ b/drivers/input/mouse/cyapa_gen5.c
@@ -250,7 +250,7 @@ struct cyapa_tsg_bin_image_data_record {
struct cyapa_tsg_bin_image {
struct cyapa_tsg_bin_image_head image_head;
- struct cyapa_tsg_bin_image_data_record records[0];
+ struct cyapa_tsg_bin_image_data_record records[];
} __packed;
struct pip_bl_packet_start {
@@ -271,7 +271,7 @@ struct pip_bl_cmd_head {
u8 report_id; /* Bootloader output report id, must be 40h */
u8 rsvd; /* Reserved, must be 0 */
struct pip_bl_packet_start packet_start;
- u8 data[0]; /* Command data variable based on commands */
+ u8 data[]; /* Command data variable based on commands */
} __packed;
/* Initiate bootload command data structure. */
@@ -300,7 +300,7 @@ struct tsg_bl_metadata_row_params {
struct tsg_bl_flash_row_head {
u8 flash_array_id;
__le16 flash_row_id;
- u8 flash_data[0];
+ u8 flash_data[];
} __packed;
struct pip_app_cmd_head {
@@ -314,7 +314,7 @@ struct pip_app_cmd_head {
* Bit 6-0: command code.
*/
u8 cmd_code;
- u8 parameter_data[0]; /* Parameter data variable based on cmd_code */
+ u8 parameter_data[]; /* Parameter data variable based on cmd_code */
} __packed;
/* Application get/set parameter command data structure */