linux_dsm_epyc7002/drivers/gpu/drm/amd
Gustavo A. R. Silva 4541ea81ed drm/[radeon|amdgpu]: 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 SISLANDS_SMC_SWSTATE.

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>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-05-28 14:00:50 -04:00
..
acp drm: amd/acp: fix broken menu structure 2020-03-13 11:52:35 -04:00
amdgpu drm/[radeon|amdgpu]: Replace one-element array and use struct_size() helper 2020-05-28 14:00:50 -04:00
amdkfd drm/amdkfd: report the real PCI bus number 2020-05-21 12:48:42 -04:00
display drm/amd/display: FW Release 1.0.11 2020-05-28 14:00:49 -04:00
include drm/amdgpu: add apu flags (v2) 2020-05-22 13:41:53 -04:00
powerplay drm/amd/powerplay: skip smu_i2c_eeprom_init/fini under sriov mode 2020-05-28 14:00:49 -04:00