Commit graph

3 commits

Author SHA1 Message Date
Gustavo A. R. Silva
94dfc73e7c treewide: uapi: Replace zero-length arrays with flexible-array members
There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].

This code was transformed with the help of Coccinelle:
(linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch)

@@
identifier S, member, array;
type T1, T2;
@@

struct S {
  ...
  T1 member;
  T2 array[
- 0
  ];
};

-fstrict-flex-arrays=3 is coming and we need to land these changes
to prevent issues like these in the short future:

../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0,
but the source string has length 2 (including NUL byte) [-Wfortify-source]
		strcpy(de3->name, ".");
		^

Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If
this breaks anything, we can use a union with a new member name.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/78
Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%25lkp@intel.com/
Acked-by: Dan Williams <dan.j.williams@intel.com> # For ndctl.h
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2022-06-28 21:26:05 +02:00
Jiri Pirko
a51486266c net: sched: remove NET_CLS_IND config option
This config option makes only couple of lines optional.
Two small helpers and an int in couple of cls structs.

Remove the config option and always compile this in.
This saves the user from unexpected surprises when he adds
a filter with ingress device match which is silently ignored
in case the config option is not set.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-15 14:06:13 -07:00
Yonghong Song
49a249c387 tools/bpftool: copy a few net uapi headers to tools directory
Commit f6f3bac08f ("tools/bpf: bpftool: add net support")
added certain networking support to bpftool.
The implementation relies on a relatively recent uapi header file
linux/tc_act/tc_bpf.h on the host which contains the marco
definition of TCA_ACT_BPF_ID.

Unfortunately, this is not the case for all distributions.
See the email message below where rhel-7.2 does not have
an up-to-date linux/tc_act/tc_bpf.h.
  https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1799211.html
Further investigation found that linux/pkt_cls.h is also needed for macro
TCA_BPF_TAG.

This patch fixed the issue by copying linux/tc_act/tc_bpf.h
and linux/pkt_cls.h from kernel include/uapi directory to
tools/include/uapi directory so building the bpftool does not depend
on host system for these files.

Fixes: f6f3bac08f ("tools/bpf: bpftool: add net support")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Cc: Li Zhijian <zhijianx.li@intel.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-09 08:18:31 +01:00