linux_dsm_epyc7002/include/linux/sched
Gustavo A. R. Silva fe946db6ca sched: topology.h: 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 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
2020-04-18 15:44:56 -05:00
..
autogroup.h
clock.h
coredump.h
cpufreq.h
cputime.h
deadline.h
debug.h
hotplug.h
idle.h
init.h
isolation.h
jobctl.h
loadavg.h
mm.h
nohz.h
numa_balancing.h
prio.h
rt.h
signal.h Merge branch 'akpm' (patches from Andrew) 2020-04-02 13:55:34 -07:00
smt.h
stat.h
sysctl.h
task_stack.h
task.h
topology.h sched: topology.h: Replace zero-length array with flexible-array member 2020-04-18 15:44:56 -05:00
types.h
user.h
wake_q.h
xacct.h