linux_dsm_epyc7002/include/soc/fsl/qe
Gustavo A. R. Silva 661ea25e53 soc: fsl: qe: 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 qe_firmware.

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")

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Qiang Zhao <qiang.zhao@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
2020-05-22 16:23:02 -05:00
..
immap_qe.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
qe_tdm.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
qe.h soc: fsl: qe: Replace one-element array and use struct_size() helper 2020-05-22 16:23:02 -05:00
ucc_fast.h soc: fsl: qe: fix sparse warnings for ucc_fast.c 2020-03-24 19:02:23 -05:00
ucc_slow.h soc: fsl: qe: fix sparse warnings for ucc_slow.c 2020-03-24 19:09:40 -05:00
ucc.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00