linux_dsm_epyc7002/include
Gustavo A. R. Silva 9c8255c888 team: Replace zero-length array with flexible-array
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]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

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 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-11 13:19:00 -07:00
..
acpi
asm-generic
clocksource
crypto
drm
dt-bindings
keys
kunit
kvm
linux team: Replace zero-length array with flexible-array 2020-05-11 13:19:00 -07:00
math-emu
media
misc
net ipv6: Replace zero-length array with flexible-array 2020-05-11 13:18:54 -07:00
pcmcia
ras
rdma
scsi
soc
sound
target
trace
uapi net: ethtool: Add attributes for cable test reports 2020-05-10 12:28:41 -07:00
vdso
video
xen