linux/drivers/infiniband
Gustavo A. R. Silva bd25c8066f RDMA/siw: Replace one-element array and use struct_size() helper
The current codebase makes use of one-element arrays in the following
form:

struct something {
    int length;
    u8 data[1];
};

struct something *instance;

instance = kmalloc(sizeof(*instance) + size, GFP_KERNEL);
instance->length = size;
memcpy(instance->data, source, size);

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. So, replace
the one-element array with a flexible-array member.

Also, make use of the new struct_size() helper to properly calculate the
size of struct siw_pbl.

This issue was found with the help of Coccinelle and, audited and fixed
_manually_.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Link: https://lore.kernel.org/r/20200519233018.GA6105@embeddedor
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-19 20:51:55 -03:00
..
core RDMA/core: Consolidate ib_create_srq flows 2020-05-17 20:35:25 -03:00
hw RDMA/mlx5: Update mlx5_ib driver name 2020-05-17 20:40:20 -03:00
sw RDMA/siw: Replace one-element array and use struct_size() helper 2020-05-19 20:51:55 -03:00
ulp rnbd/rtrs: Pass max segment size from blk user to the rdma library 2020-05-19 20:43:26 -03:00
Kconfig RDMA/rtrs: include client and server modules into kernel compilation 2020-05-17 18:57:15 -03:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00