diff mbox series

[13/13] flex-array: warn when a flexible array member has some padding

Message ID 20200930231828.66751-14-luc.vanoostenryck@gmail.com (mailing list archive)
State Rejected, archived
Headers show
Series add warnings for flexible arrays | expand

Commit Message

Luc Van Oostenryck Sept. 30, 2020, 11:18 p.m. UTC 
If some padding is added because of the presence of a flexible
array member, the size of the structure will be greater than
the offset of this flexible array which can cause some
problems if the assumption is made that these 2 size must be
identical (which is easy to do since such flexible arrays are
conceptually 'after' the structure itself).

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
 options.c                       | 2 ++
 options.h                       | 1 +
 sparse.1                        | 6 ++++++
 symbol.c                        | 2 ++
 validation/flex-array-padding.c | 1 -
 5 files changed, 11 insertions(+), 1 deletion(-)

Comments

Linus Torvalds Oct. 1, 2020, 4:34 p.m. UTC | #1 
On Wed, Sep 30, 2020 at 4:18 PM Luc Van Oostenryck
<luc.vanoostenryck@gmail.com> wrote:
>
> If some padding is added because of the presence of a flexible
> array member, the size of the structure will be greater than
> the offset of this flexible array which can cause some
> problems if the assumption is made that these 2 size must be
> identical (which is easy to do since such flexible arrays are
> conceptually 'after' the structure itself).

The warning seems pointless, and the explanation above is wrong.

Flexible array padding is normal and good. IOW, if you have

    struct odd_struct {
        char c;
        unsigned int flex[];
    };

then the flexible array - and the structure - very much should be
aligned on 'unsigned int', and both the offset of the flex-array and
the (bogus) size of the structure is 4.

So this is a normal case and nothing wrong with it, and the above is
the "flexible array caused padding" one (but sizeof and offsetof
match).

And the case that causes sizeof() and offsetof() to not match is
normal too: but is not that the flexible array member caused padding,
but that *other* members did.

IOW, maybe you have a structure like this:

    struct other {
        uint64_t a;
        uint32_t b;
        char flex[];
    };

and now "offsetof(flex)" is 12, but "sizeof(struct other)" is 16,
because the flex-array itself has no real alignment requirement and
will just be laid out after the 12 bytes of a/b, but the structure has
8-byte alignment due to 'a'.

So I don't think the warning is interesting, because this is a
perfectly normal condition too.

And I don't think your explanation for the warning makes sense,
because you say "padding is added because of the presence of a
flexible array member", but that's not at all what is going on. The
padding is added because of *other* members.

Anyway, the above is just an example of why "sizeof()" itself makes no
sense on these things. A "sizeof()" of a structure with a flexible
array member is inherently pointless. You can't use it for anything
really valid, and it doesn't have any sensible meaning.

But I don't think that has anything to do with warning about padding.
The padding is right - it's the sizeof() itself that is nonsensical.

So in the kernel, we would

 - start warning about 'sizeof(flex_struct)'

 - make our "struct_size(s, m, N)" construct use
"offsetof(m)+N*sizeof(*m)" instead of using sizeof().

Of course, it may well be that we end up with trouble just because we
end up _needing_ sizeof() for some reason. I can't think of any sane
situation off the top of my head, but who knows what odd macros etc we
might have that end up doing sizeof() as part of things..

                  Linus
Luc Van Oostenryck Oct. 1, 2020, 7:17 p.m. UTC | #2 
On Thu, Oct 01, 2020 at 09:34:37AM -0700, Linus Torvalds wrote:
> On Wed, Sep 30, 2020 at 4:18 PM Luc Van Oostenryck
> <luc.vanoostenryck@gmail.com> wrote:
> >
> > If some padding is added because of the presence of a flexible
> > array member, the size of the structure will be greater than
> > the offset of this flexible array which can cause some
> > problems if the assumption is made that these 2 size must be
> > identical (which is easy to do since such flexible arrays are
> > conceptually 'after' the structure itself).
> 
> The warning seems pointless, and the explanation above is wrong.
> 
> Flexible array padding is normal and good. IOW, if you have
> 
>     struct odd_struct {
>         char c;
>         unsigned int flex[];
>     };
> 
> then the flexible array - and the structure - very much should be
> aligned on 'unsigned int', and both the offset of the flex-array and
> the (bogus) size of the structure is 4.
> 
> So this is a normal case and nothing wrong with it, and the above is
> the "flexible array caused padding" one (but sizeof and offsetof
> match).
> 
> And the case that causes sizeof() and offsetof() to not match is
> normal too: but is not that the flexible array member caused padding,
> but that *other* members did.
> 
> IOW, maybe you have a structure like this:
> 
>     struct other {
>         uint64_t a;
>         uint32_t b;
>         char flex[];
>     };
> 
> and now "offsetof(flex)" is 12, but "sizeof(struct other)" is 16,
> because the flex-array itself has no real alignment requirement and
> will just be laid out after the 12 bytes of a/b, but the structure has
> 8-byte alignment due to 'a'.
> 
> So I don't think the warning is interesting, because this is a
> perfectly normal condition too.
> 
> And I don't think your explanation for the warning makes sense,
> because you say "padding is added because of the presence of a
> flexible array member", but that's not at all what is going on. The
> padding is added because of *other* members.

Yes, my explanation is completely wrong. The warning is indeed just
about sizeof() != offset() and I added because it seemed odd to me
but ...

> Anyway, the above is just an example of why "sizeof()" itself makes no
> sense on these things. A "sizeof()" of a structure with a flexible
> array member is inherently pointless. You can't use it for anything
> really valid, and it doesn't have any sensible meaning.
> 
> But I don't think that has anything to do with warning about padding.
> The padding is right - it's the sizeof() itself that is nonsensical.

Yes, indeed, it's perfectly normal. I'll drop this patch.
 
> So in the kernel, we would
> 
>  - start warning about 'sizeof(flex_struct)'

Adding this warning by default annoys me slightly because it will
add 5700+ warnings to the 18000 already present and I think sparse
is already underused because it is very/too noisy. But I guess that
most occurrences come from a few macros and thus should be easy to
get rid off.

>  - make our "struct_size(s, m, N)" construct use
> "offsetof(m)+N*sizeof(*m)" instead of using sizeof().

This accounts for only 432 occurences of sizeof(flex-array),
leaving 5287 other ones.

> Of course, it may well be that we end up with trouble just because we
> end up _needing_ sizeof() for some reason. I can't think of any sane
> situation off the top of my head, but who knows what odd macros etc we
> might have that end up doing sizeof() as part of things..

Well, yes, for my part, I find the number of nested flexible arrays a
bit worrying and much less sensical than the sizeof but .. live and see.

-- Luc
Linus Torvalds Oct. 1, 2020, 7:27 p.m. UTC | #3 
On Thu, Oct 1, 2020 at 12:17 PM Luc Van Oostenryck
<luc.vanoostenryck@gmail.com> wrote:
>
> > So in the kernel, we would
> >
> >  - start warning about 'sizeof(flex_struct)'
>
> Adding this warning by default annoys me slightly because it will
> add 5700+ warnings to the 18000 already present and I think sparse
> is already underused because it is very/too noisy. But I guess that
> most occurrences come from a few macros and thus should be easy to
> get rid off.

Hopefully. I'll try to take a look. Do you have the sparse changes in
a git branch already so that I can just try that directly?

Or if you send me a couple of examples, maybe it's just the same
pattern over and over,..

            Linus
Luc Van Oostenryck Oct. 1, 2020, 7:41 p.m. UTC | #4 
On Thu, Oct 01, 2020 at 12:27:56PM -0700, Linus Torvalds wrote:
> On Thu, Oct 1, 2020 at 12:17 PM Luc Van Oostenryck
> <luc.vanoostenryck@gmail.com> wrote:
> >
> > > So in the kernel, we would
> > >
> > >  - start warning about 'sizeof(flex_struct)'
> >
> > Adding this warning by default annoys me slightly because it will
> > add 5700+ warnings to the 18000 already present and I think sparse
> > is already underused because it is very/too noisy. But I guess that
> > most occurrences come from a few macros and thus should be easy to
> > get rid off.
> 
> Hopefully. I'll try to take a look. Do you have the sparse changes in
> a git branch already so that I can just try that directly?

What I posted yesterday is on
	git://git.kernel.org/pub/scm/devel/sparse/sparse-dev.git flex-array

> Or if you send me a couple of examples, maybe it's just the same
> pattern over and over,..

Well, the 888 occurences I see are already 'unique' occurences
(in the sense that the warning is from a distinct file+position).
I'm adding in attachment the extract of my test logs (but it is
on v5.9-rc1 so it's maybe not much usefull). I ddn't investigated
anything, just checked a few case to see that it was a genuine
occurrence.

-- Luc
268 ./include/net/ip.h:44:8: warning: nested flexible arrays
    228 ./include/linux/tty.h:85:8: warning: nested flexible arrays
    228 ./include/linux/tty.h:230:8: warning: nested flexible arrays
    219 ./include/crypto/hash.h:231:8: warning: nested flexible arrays
    141 ./include/linux/ieee80211.h:1119:39: warning: nested flexible arrays
    141 ./include/linux/ieee80211.h:1103:31: warning: nested flexible arrays
    141 ./include/linux/ieee80211.h:1101:24: warning: nested flexible arrays
    141 ./include/linux/ieee80211.h:1047:15: warning: nested flexible arrays
    141 ./include/linux/ieee80211.h:1040:8: warning: nested flexible arrays
    134 ./include/crypto/skcipher.h:37:8: warning: nested flexible arrays
    129 net/mac80211/ieee80211_i.h:871:8: warning: nested flexible arrays
    121 net/mac80211/sta_info.h:535:8: warning: nested flexible arrays
    102 ./include/crypto/aead.h:152:8: warning: nested flexible arrays
    100 fs/ocfs2/ocfs2_fs.h:725:15: warning: nested flexible arrays
     88 drivers/net/wireless/marvell/mwifiex/fw.h:2309:15: warning: nested flexible arrays
     74 ./include/crypto/hash.h:216:8: warning: nested flexible arrays
     63 ./include/net/inet_sock.h:58:8: warning: nested flexible arrays
     61 ./include/linux/serial_core.h:285:8: warning: nested flexible arrays
     59 net/wireless/core.h:24:8: warning: nested flexible arrays
     56 drivers/md/bcache/bcache.h:507:8: warning: nested flexible arrays
     56 ./include/linux/console_struct.h:94:8: warning: nested flexible arrays
     55 ./include/net/tcp.h:872:23: warning: nested flexible arrays
     55 ./include/net/tcp.h:859:15: warning: nested flexible arrays
     55 ./include/net/tcp.h:825:8: warning: nested flexible arrays
     51 ./include/linux/usb/serial.h:72:8: warning: nested flexible arrays
     47 ./include/net/flow_offload.h:377:8: warning: nested flexible arrays
     46 ./include/crypto/skcipher.h:43:8: warning: nested flexible arrays
     44 ./include/net/xfrm.h:589:15: warning: nested flexible arrays
     44 ./include/net/xfrm.h:588:8: warning: nested flexible arrays
     42 drivers/md/bcache/bcache.h:231:8: warning: nested flexible arrays
     39 ./include/linux/crypto.h:639:8: warning: nested flexible arrays
     37 net/mac80211/key.h:59:8: warning: nested flexible arrays
     36 fs/ext4/ext4.h:2188:16: warning: nested flexible arrays
     36 ./include/rdma/ib_verbs.h:2055:7: warning: nested flexible arrays
     36 ./include/crypto/internal/aead.h:21:24: warning: nested flexible arrays
     36 ./include/crypto/internal/aead.h:20:15: warning: nested flexible arrays
     36 ./include/crypto/internal/aead.h:18:8: warning: nested flexible arrays
     35 arch/x86/events/intel/../perf_event.h:199:8: warning: nested flexible arrays
     34 net/wireless/core.h:150:8: warning: nested flexible arrays
     30 net/mac80211/ieee80211_i.h:836:8: warning: nested flexible arrays
     26 drivers/net/wireless/ath/ath10k/htt.h:1811:15: warning: nested flexible arrays
     26 ./include/net/xfrm.h:661:8: warning: nested flexible arrays
     26 ./include/net/sctp/structs.h:1548:8: warning: nested flexible arrays
     26 ./include/linux/sctp.h:275:8: warning: nested flexible arrays
     24 net/mac80211/ieee80211_i.h:797:8: warning: nested flexible arrays
     24 drivers/md/bcache/journal.h:128:8: warning: nested flexible arrays
     24 drivers/md/bcache/bcache.h:407:8: warning: nested flexible arrays
     24 ./include/net/mac80211.h:2572:8: warning: nested flexible arrays
     24 ./include/linux/hyperv.h:725:8: warning: nested flexible arrays
     24 ./include/linux/hyperv.h:685:8: warning: nested flexible arrays
     24 ./include/linux/errqueue.h:15:15: warning: nested flexible arrays
     24 ./include/linux/errqueue.h:14:8: warning: nested flexible arrays
     24 ./include/linux/cgroup-defs.h:494:8: warning: nested flexible arrays
     24 ./include/acpi/actypes.h:1156:8: warning: nested flexible arrays
     23 ./include/crypto/internal/skcipher.h:22:24: warning: nested flexible arrays
     23 ./include/crypto/internal/skcipher.h:21:15: warning: nested flexible arrays
     23 ./include/crypto/internal/skcipher.h:19:8: warning: nested flexible arrays
     22 drivers/net/wireless/intel/iwlwifi/fw/api/dbg-tlv.h:219:8: warning: nested flexible arrays
     21 ./include/crypto/rng.h:54:8: warning: nested flexible arrays
     21 ./include/crypto/akcipher.h:48:8: warning: nested flexible arrays
     20 fs/ocfs2/ocfs2_fs.h:662:8: warning: nested flexible arrays
     20 ./include/net/xfrm.h:607:8: warning: nested flexible arrays
     20 ./include/net/inet_sock.h:63:8: warning: nested flexible arrays
     19 security/apparmor/include/policy.h:129:8: warning: nested flexible arrays
     19 ./include/net/xfrm.h:629:8: warning: nested flexible arrays
     18 ./include/crypto/internal/hash.h:46:24: warning: nested flexible arrays
     18 ./include/crypto/internal/hash.h:45:15: warning: nested flexible arrays
     18 ./include/crypto/internal/hash.h:43:8: warning: nested flexible arrays
     16 drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_utils.h:235:15: warning: nested flexible arrays
     16 drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_utils.h:232:17: warning: nested flexible arrays
     16 drivers/net/ethernet/aquantia/atlantic/aq_hw.h:173:8: warning: nested flexible arrays
     16 drivers/md/bcache/bcache.h:298:8: warning: nested flexible arrays
     16 ./drivers/net/wireless/intel/iwlwifi/mvm/..//fw/api/dbg-tlv.h:219:8: warning: nested flexible arrays
     15 ./include/crypto/kpp.h:42:8: warning: nested flexible arrays
     14 fs/dlm/dlm_internal.h:518:8: warning: nested flexible arrays
     14 drivers/md/bcache/journal.h:119:9: warning: nested flexible arrays
     14 drivers/md/bcache/journal.h:104:8: warning: nested flexible arrays
     14 drivers/md/bcache/bcache.h:675:9: warning: nested flexible arrays
     14 drivers/md/bcache/bcache.h:227:9: warning: nested flexible arrays
     14 drivers/md/bcache/bcache.h:225:8: warning: nested flexible arrays
     14 ./include/linux/pci.h:297:8: warning: nested flexible arrays
     13 ./include/crypto/internal/scompress.h:15:8: warning: nested flexible arrays
     12 ./include/net/udp.h:40:15: warning: nested flexible arrays
     12 ./include/net/udp.h:39:8: warning: nested flexible arrays
     12 ./include/linux/jbd2.h:1603:16: warning: nested flexible arrays
     11 drivers/nvme/target/nvmet.h:323:24: warning: nested flexible arrays
     11 drivers/nvme/target/nvmet.h:322:15: warning: nested flexible arrays
     11 drivers/nvme/target/nvmet.h:313:8: warning: nested flexible arrays
     11 drivers/net/wireless/marvell/mwifiex/fw.h:2304:8: warning: nested flexible arrays
     11 drivers/net/wireless/marvell/mwifiex/fw.h:1149:8: warning: nested flexible arrays
     11 ./drivers/net/wireless/intel/iwlwifi/dvm/..//fw/api/dbg-tlv.h:219:8: warning: nested flexible arrays
     10 sound/usb/caiaq/device.h:60:8: warning: nested flexible arrays
     10 drivers/net/wireless/ath/carl9170/fwcmd.h:230:15: warning: nested flexible arrays
     10 drivers/net/wireless/ath/carl9170/fwcmd.h:228:8: warning: nested flexible arrays
     10 drivers/net/wireless/ath/carl9170/carl9170.h:375:15: warning: nested flexible arrays
     10 drivers/net/wireless/ath/carl9170/carl9170.h:233:8: warning: nested flexible arrays
     10 drivers/md/bcache/bset.h:157:8: warning: nested flexible arrays
     10 ./include/sound/intel-nhlt.h:66:8: warning: nested flexible arrays
     10 ./include/pcmcia/cistpl.h:533:15: warning: nested flexible arrays
      9 drivers/md/bcache/btree.h:122:9: warning: nested flexible arrays
      9 drivers/md/bcache/btree.h:117:8: warning: nested flexible arrays
      9 ./include/linux/crypto.h:643:8: warning: nested flexible arrays
      9 ./include/crypto/acompress.h:47:8: warning: nested flexible arrays
      8 net/dccp/dccp.h:339:15: warning: nested flexible arrays
      8 net/dccp/dccp.h:338:8: warning: nested flexible arrays
      8 fs/ocfs2/ocfs2_fs.h:968:15: warning: nested flexible arrays
      8 fs/ocfs2/ocfs2_fs.h:898:24: warning: nested flexible arrays
      8 fs/ocfs2/ocfs2_fs.h:896:15: warning: nested flexible arrays
      8 fs/ocfs2/ocfs2_fs.h:878:8: warning: nested flexible arrays
      8 drivers/scsi/hisi_sas/hisi_sas.h:565:15: warning: nested flexible arrays
      8 drivers/net/wireless/intel/iwlegacy/common.h:549:8: warning: nested flexible arrays
      8 drivers/net/wireless/intel/iwlegacy/commands.h:3335:8: warning: nested flexible arrays
      8 drivers/net/wireless/intel/iwlegacy/commands.h:1195:8: warning: nested flexible arrays
      8 drivers/md/dm-rq.h:27:8: warning: nested flexible arrays
      8 drivers/md/bcache/bcache.h:738:8: warning: nested flexible arrays
      8 drivers/infiniband/hw/i40iw/i40iw_cm.h:354:15: warning: nested flexible arrays
      8 crypto/gcm.c:71:15: warning: nested flexible arrays
      8 crypto/ccm.c:46:15: warning: nested flexible arrays
      8 ./include/rdma/ib_verbs.h:2020:8: warning: nested flexible arrays
      8 ./include/rdma/ib_verbs.h:2007:8: warning: nested flexible arrays
      8 ./include/rdma/ib_verbs.h:1992:8: warning: nested flexible arrays
      8 ./include/rdma/ib_verbs.h:1978:8: warning: nested flexible arrays
      8 ./include/rdma/ib_verbs.h:1963:8: warning: nested flexible arrays
      8 ./include/rdma/ib_verbs.h:1949:8: warning: nested flexible arrays
      8 ./include/rdma/ib_verbs.h:1931:8: warning: nested flexible arrays
      8 ./include/rdma/ib_verbs.h:1906:8: warning: nested flexible arrays
      8 ./include/rdma/ib_verbs.h:1892:8: warning: nested flexible arrays
      8 ./include/net/cfg80211.h:2830:8: warning: nested flexible arrays
      8 ./include/crypto/internal/akcipher.h:16:24: warning: nested flexible arrays
      8 ./include/crypto/internal/akcipher.h:15:15: warning: nested flexible arrays
      8 ./include/crypto/internal/akcipher.h:13:8: warning: nested flexible arrays
      7 fs/btrfs/volumes.h:289:8: warning: nested flexible arrays
      7 drivers/net/wireless/ti/wl1251/acx.h:16:8: warning: nested flexible arrays
      7 drivers/clk/samsung/clk.h:22:8: warning: nested flexible arrays
      7 ./include/linux/mlx5/mlx5_ifc.h:3363:8: warning: nested flexible arrays
      6 fs/ocfs2/ocfs2_fs.h:844:15: warning: nested flexible arrays
      6 fs/ocfs2/ocfs2_fs.h:505:8: warning: nested flexible arrays
      6 fs/ocfs2/ocfs2_fs.h:1083:15: warning: nested flexible arrays
      6 fs/cifs/cifsglob.h:135:8: warning: nested flexible arrays
      6 drivers/scsi/aic94xx/aic94xx_sas.h:574:15: warning: nested flexible arrays
      6 drivers/scsi/aic94xx/aic94xx_sas.h:572:8: warning: nested flexible arrays
      6 drivers/scsi/aic94xx/aic94xx_sas.h:319:8: warning: nested flexible arrays
      6 drivers/net/wireless/wl3501.h:382:8: warning: nested flexible arrays
      6 drivers/net/wireless/wl3501.h:309:8: warning: nested flexible arrays
      6 drivers/net/wireless/ti/wlcore/acx.h:54:8: warning: nested flexible arrays
      6 drivers/md/raid5.h:249:16: warning: nested flexible arrays
      6 ./include/uapi/linux/bcache.h:345:8: warning: nested flexible arrays
      6 ./include/linux/mlx5/mlx5_ifc.h:7681:8: warning: nested flexible arrays
      6 ./include/linux/mlx5/mlx5_ifc.h:3265:8: warning: nested flexible arrays
      6 ./include/linux/ceph/osdmap.h:144:15: warning: nested flexible arrays
      6 ./include/crypto/if_alg.h:109:15: warning: nested flexible arrays
      5 drivers/scsi/qla2xxx/qla_dbg.h:301:15: warning: nested flexible arrays
      5 drivers/scsi/qla2xxx/qla_dbg.h:276:8: warning: nested flexible arrays
      5 drivers/scsi/isci/request.h:82:8: warning: nested flexible arrays
      5 drivers/scsi/isci/request.h:137:31: warning: nested flexible arrays
      5 drivers/scsi/isci/request.h:132:24: warning: nested flexible arrays
      5 drivers/scsi/isci/request.h:131:15: warning: nested flexible arrays
      5 drivers/net/wireless/wl3501.h:439:8: warning: nested flexible arrays
      5 drivers/net/wireless/ti/wl1251/acx.h:149:8: warning: nested flexible arrays
      5 drivers/net/wireless/microchip/wilc1000/spi.c:52:15: warning: nested flexible arrays
      5 arch/x86/events/zhaoxin/../perf_event.h:199:8: warning: nested flexible arrays
      5 arch/x86/events/perf_event.h:199:8: warning: nested flexible arrays
      5 arch/x86/events/intel/../perf_event.h:794:24: warning: nested flexible arrays
      5 arch/x86/events/intel/../perf_event.h:792:15: warning: nested flexible arrays
      5 arch/x86/events/intel/../perf_event.h:789:8: warning: nested flexible arrays
      5 arch/x86/events/amd/../perf_event.h:199:8: warning: nested flexible arrays
      5 ./include/linux/mlx5/mlx5_ifc.h:7705:8: warning: nested flexible arrays
      5 ./include/linux/mlx5/mlx5_ifc.h:7627:8: warning: nested flexible arrays
      5 ./include/linux/iomap.h:191:8: warning: nested flexible arrays
      5 ./include/linux/ecryptfs.h:93:8: warning: nested flexible arrays
      5 ./include/linux/ecryptfs.h:100:15: warning: nested flexible arrays
      5 ./include/linux/ceph/ceph_fs.h:508:8: warning: nested flexible arrays
      5 ./include/crypto/internal/hash.h:35:24: warning: nested flexible arrays
      5 ./include/crypto/internal/hash.h:34:15: warning: nested flexible arrays
      5 ./include/crypto/internal/hash.h:32:8: warning: nested flexible arrays
      5 ./drivers/net/wireless/intel/iwlwifi/mvm/..//fw/api/scan.h:827:15: warning: nested flexible arrays
      4 sound/core/vmaster.c:47:8: warning: nested flexible arrays
      4 net/xfrm/xfrm_input.c:32:15: warning: nested flexible arrays
      4 net/xfrm/xfrm_input.c:31:8: warning: nested flexible arrays
      4 net/ipv6/esp6.c:42:8: warning: nested flexible arrays
      4 net/ipv6/ah6.c:42:8: warning: nested flexible arrays
      4 net/ipv4/inet_fragment.c:36:15: warning: nested flexible arrays
      4 net/ipv4/inet_fragment.c:35:8: warning: nested flexible arrays
      4 net/ipv4/icmp.c:100:8: warning: nested flexible arrays
      4 net/ieee802154/core.h:7:8: warning: nested flexible arrays
      4 kernel/trace/trace_uprobe.c:55:8: warning: nested flexible arrays
      4 kernel/trace/trace_kprobe.c:55:8: warning: nested flexible arrays
      4 kernel/bpf/core.c:1857:15: warning: nested flexible arrays
      4 kernel/bpf/core.c:1843:15: warning: nested flexible arrays
      4 fs/squashfs/squashfs_fs.h:395:7: warning: nested flexible arrays
      4 fs/ocfs2/ocfs2_fs.h:942:8: warning: nested flexible arrays
      4 fs/notify/fdinfo.c:43:16: warning: nested flexible arrays
      4 fs/nfs_common/nfsacl.c:43:8: warning: nested flexible arrays
      4 fs/ext4/mballoc.c:2407:16: warning: nested flexible arrays
      4 fs/dlm/dlm_internal.h:455:7: warning: nested flexible arrays
      4 fs/block_dev.c:264:8: warning: nested flexible arrays
      4 drivers/scsi/hisi_sas/hisi_sas.h:587:8: warning: nested flexible arrays
      4 drivers/scsi/hisi_sas/hisi_sas.h:576:7: warning: nested flexible arrays
      4 drivers/scsi/hisi_sas/hisi_sas.h:566:24: warning: nested flexible arrays
      4 drivers/scsi/hisi_sas/hisi_sas.h:563:8: warning: nested flexible arrays
      4 drivers/pcmcia/pcmcia_cis.c:138:8: warning: nested flexible arrays
      4 drivers/net/wireless/ti/wlcore/acx.h:474:8: warning: nested flexible arrays
      4 drivers/net/wireless/intel/iwlegacy/common.h:551:15: warning: nested flexible arrays
      4 drivers/net/wireless/intel/iwlegacy/commands.h:3348:15: warning: nested flexible arrays
      4 drivers/net/ethernet/sfc/vfdi.h:167:15: warning: nested flexible arrays
      4 drivers/net/ethernet/aquantia/atlantic/hw_atl/../hw_atl/hw_atl_utils.h:235:15: warning: nested flexible arrays
      4 drivers/net/ethernet/aquantia/atlantic/hw_atl/../hw_atl/hw_atl_utils.h:232:17: warning: nested flexible arrays
      4 drivers/net/ethernet/aquantia/atlantic/hw_atl/../aq_hw.h:173:8: warning: nested flexible arrays
      4 drivers/md/dm.c:95:8: warning: nested flexible arrays
      4 drivers/md/dm.c:80:8: warning: nested flexible arrays
      4 drivers/md/bcache/bcache.h:740:15: warning: nested flexible arrays
      4 drivers/infiniband/hw/i40iw/i40iw_cm.h:315:8: warning: nested flexible arrays
      4 drivers/infiniband/hw/cxgb4/t4.h:98:7: warning: nested flexible arrays
      4 drivers/gpu/drm/amd/amdgpu/si_dpm.h:799:8: warning: nested flexible arrays
      4 drivers/firmware/efi/libstub/file.c:32:8: warning: nested flexible arrays
      4 drivers/firmware/efi/libstub/efi-stub-helper.c:428:21: warning: nested flexible arrays
      4 crypto/rsa-pkcs1pad.c:100:8: warning: nested flexible arrays
      4 crypto/gcm.c:98:16: warning: nested flexible arrays
      4 crypto/gcm.c:63:8: warning: nested flexible arrays
      4 crypto/gcm.c:53:8: warning: nested flexible arrays
      4 crypto/gcm.c:37:8: warning: nested flexible arrays
      4 crypto/drbg.c:1669:8: warning: nested flexible arrays
      4 crypto/ctr.c:22:8: warning: nested flexible arrays
      4 crypto/ccm.c:39:8: warning: nested flexible arrays
      4 crypto/ccm.c:33:8: warning: nested flexible arrays
      4 crypto/asymmetric_keys/restrict.c:19:15: warning: nested flexible arrays
      4 ./include/scsi/fc_encode.h:27:15: warning: nested flexible arrays
      4 ./include/net/sctp/structs.h:1117:15: warning: nested flexible arrays
      4 ./include/net/sctp/structs.h:1116:8: warning: nested flexible arrays
      4 ./include/net/nsh.h:213:15: warning: nested flexible arrays
      4 ./include/net/nsh.h:208:8: warning: nested flexible arrays
      4 ./include/linux/sctp.h:724:8: warning: nested flexible arrays
      4 ./include/linux/mlx5/mlx5_ifc.h:6331:8: warning: nested flexible arrays
      4 ./include/linux/mlx5/mlx5_ifc.h:6224:8: warning: nested flexible arrays
      3 sound/usb/6fire/comm.h:19:8: warning: nested flexible arrays
      3 net/netfilter/x_tables.c:796:8: warning: nested flexible arrays
      3 net/netfilter/x_tables.c:791:8: warning: nested flexible arrays
      3 fs/overlayfs/overlayfs.h:102:15: warning: nested flexible arrays
      3 fs/overlayfs/overlayfs.h:100:8: warning: nested flexible arrays
      3 fs/ocfs2/ocfs2_fs.h:815:8: warning: nested flexible arrays
      3 fs/ocfs2/ocfs2_fs.h:1066:8: warning: nested flexible arrays
      3 fs/ocfs2/ocfs2_fs.h:1046:8: warning: nested flexible arrays
      3 fs/ocfs2/ocfs2_fs.h:1033:8: warning: nested flexible arrays
      3 fs/f2fs/f2fs.h:1701:16: warning: nested flexible arrays
      3 drivers/tty/hvc/hvc_console.h:35:8: warning: nested flexible arrays
      3 drivers/staging/wlan-ng/hfa384x.h:1229:8: warning: nested flexible arrays
      3 drivers/staging/rtl8192u/ieee80211/ieee80211.h:977:8: warning: nested flexible arrays
      3 drivers/nvdimm/nd.h:163:8: warning: nested flexible arrays
      3 drivers/net/wireless/ti/wl18xx/../wlcore/acx.h:54:8: warning: nested flexible arrays
      3 drivers/net/wireless/ti/wl12xx/../wlcore/acx.h:54:8: warning: nested flexible arrays
      3 drivers/net/wireless/ath/ath10k/htt.h:1793:15: warning: nested flexible arrays
      3 drivers/net/ethernet/intel/ice/ice_adminq_cmd.h:664:15: warning: nested flexible arrays
      3 drivers/infiniband/hw/cxgb4/t4fw_ri_api.h:646:8: warning: nested flexible arrays
      3 drivers/infiniband/hw/cxgb4/t4.h:113:7: warning: nested flexible arrays
      3 drivers/gpu/drm/nouveau/nvif/notify.c:169:16: warning: nested flexible arrays
      3 drivers/gpu/drm/nouveau/nouveau_svm.c:73:8: warning: nested flexible arrays
      3 drivers/crypto/ccp/ccp-crypto.h:112:8: warning: nested flexible arrays
      3 drivers/clk/x86/clk-cgu.h:79:8: warning: nested flexible arrays
      3 ./include/uapi/linux/bcache.h:355:9: warning: nested flexible arrays
      3 ./include/uapi/linux/bcache.h:354:9: warning: nested flexible arrays
      3 ./include/scsi/scsi_bsg_iscsi.h:69:15: warning: nested flexible arrays
      3 ./include/scsi/scsi_bsg_iscsi.h:67:8: warning: nested flexible arrays
      3 ./include/linux/sctp.h:664:8: warning: nested flexible arrays
      3 ./include/linux/sctp.h:227:8: warning: nested flexible arrays
      3 ./include/linux/mlx5/mlx5_ifc.h:6297:8: warning: nested flexible arrays
      3 ./include/linux/mlx5/mlx5_ifc.h:4789:8: warning: nested flexible arrays
      3 ./include/linux/mlx5/mlx5_ifc.h:4227:8: warning: nested flexible arrays
      3 ./include/crypto/if_alg.h:95:8: warning: nested flexible arrays
      2 sound/usb/6fire/midi.h:15:8: warning: nested flexible arrays
      2 security/integrity/evm/evm.h:46:8: warning: nested flexible arrays
      2 net/nfc/hci/hci.h:21:8: warning: nested flexible arrays
      2 net/netfilter/nft_set_pipapo.h:175:8: warning: nested flexible arrays
      2 net/dccp/ccids/lib/../../dccp.h:339:15: warning: nested flexible arrays
      2 net/dccp/ccids/lib/../../dccp.h:338:8: warning: nested flexible arrays
      2 net/dccp/ccids/../dccp.h:339:15: warning: nested flexible arrays
      2 net/dccp/ccids/../dccp.h:338:8: warning: nested flexible arrays
      2 fs/xfs/xfs_rmap_item.h:46:8: warning: nested flexible arrays
      2 fs/xfs/xfs_refcount_item.h:45:8: warning: nested flexible arrays
      2 fs/xfs/xfs_log_priv.h:195:16: warning: nested flexible arrays
      2 fs/xfs/xfs_bmap_item.h:43:8: warning: nested flexible arrays
      2 fs/ocfs2/ocfs2_fs.h:858:8: warning: nested flexible arrays
      2 fs/notify/fanotify/fanotify.h:169:8: warning: nested flexible arrays
      2 fs/notify/fanotify/fanotify.h:155:8: warning: nested flexible arrays
      2 fs/ecryptfs/ecryptfs_kernel.h:364:8: warning: nested flexible arrays
      2 fs/cifs/smb2inode.c:50:8: warning: nested flexible arrays
      2 drivers/staging/rtl8192u/ieee80211/ieee80211.h:1008:8: warning: nested flexible arrays
      2 drivers/staging/rtl8192e/rtllib.h:824:8: warning: nested flexible arrays
      2 drivers/scsi/isci/task.h:88:15: warning: nested flexible arrays
      2 drivers/scsi/isci/task.h:84:8: warning: nested flexible arrays
      2 drivers/scsi/hisi_sas/hisi_sas.h:593:8: warning: nested flexible arrays
      2 drivers/net/wireless/wl3501.h:575:8: warning: nested flexible arrays
      2 drivers/net/wireless/ti/wlcore/wl12xx_80211.h:109:8: warning: nested flexible arrays
      2 drivers/net/wireless/ti/wl18xx/acx.h:266:8: warning: nested flexible arrays
      2 drivers/net/wireless/ti/wl12xx/acx.h:241:8: warning: nested flexible arrays
      2 drivers/net/wireless/ti/wl1251/wl12xx_80211.h:120:8: warning: nested flexible arrays
      2 drivers/net/wireless/ti/wl1251/acx.h:1060:8: warning: nested flexible arrays
      2 drivers/net/wireless/quantenna/qtnfmac/qlink.h:1645:8: warning: nested flexible arrays
      2 drivers/net/wireless/quantenna/qtnfmac/qlink.h:1569:8: warning: nested flexible arrays
      2 drivers/net/wireless/intel/iwlwifi/mvm/sta.h:351:8: warning: nested flexible arrays
      2 drivers/net/wireless/intel/iwlwifi/fw/api/dbg-tlv.h:246:8: warning: nested flexible arrays
      2 drivers/net/wireless/intel/iwlwifi/fw/api/dbg-tlv.h:203:8: warning: nested flexible arrays
      2 drivers/net/wireless/intel/iwlwifi/fw/api/dbg-tlv.h:178:8: warning: nested flexible arrays
      2 drivers/net/wireless/intel/iwlegacy/commands.h:2662:8: warning: nested flexible arrays
      2 drivers/net/wireless/intel/iwlegacy/3945.h:126:15: warning: nested flexible arrays
      2 drivers/net/wireless/intel/iwlegacy/3945.h:125:8: warning: nested flexible arrays
      2 drivers/net/wireless/intel/ipw2x00/libipw.h:477:8: warning: nested flexible arrays
      2 drivers/net/wireless/intel/ipw2x00/libipw.h:448:8: warning: nested flexible arrays
      2 drivers/net/wireless/ath/ath10k/htt.h:1809:8: warning: nested flexible arrays
      2 drivers/net/ethernet/mellanox/mlx5/core/en_accel/tls.h:59:8: warning: nested flexible arrays
      2 drivers/media/platform/xilinx/xilinx-dma.h:73:8: warning: nested flexible arrays
      2 drivers/md/bcache/request.h:5:8: warning: nested flexible arrays
      2 drivers/md/bcache/request.h:33:9: warning: nested flexible arrays
      2 drivers/md/bcache/request.c:463:8: warning: nested flexible arrays
      2 drivers/md/bcache/movinggc.c:15:8: warning: nested flexible arrays
      2 drivers/md/bcache/journal.h:83:8: warning: nested flexible arrays
      2 drivers/infiniband/sw/rdmavt/mr.h:53:8: warning: nested flexible arrays
      2 drivers/infiniband/hw/mlx5/fs.c:1058:23: warning: nested flexible arrays
      2 drivers/infiniband/hw/cxgb4/t4fw_ri_api.h:611:15: warning: nested flexible arrays
      2 drivers/infiniband/hw/cxgb4/t4fw_ri_api.h:598:8: warning: nested flexible arrays
      2 drivers/infiniband/hw/cxgb4/t4.h:392:8: warning: nested flexible arrays
      2 drivers/infiniband/core/uverbs_ioctl.c:43:8: warning: nested flexible arrays
      2 drivers/gpu/drm/nouveau/nvif/object.c:61:16: warning: nested flexible arrays
      2 drivers/gpu/drm/nouveau/nvif/object.c:266:16: warning: nested flexible arrays
      2 drivers/gpu/drm/nouveau/nvif/object.c:185:16: warning: nested flexible arrays
      2 drivers/gpu/drm/nouveau/nvif/object.c:142:16: warning: nested flexible arrays
      2 drivers/gpu/drm/amd/amdgpu/amdgpu_ucode.h:293:7: warning: nested flexible arrays
      2 drivers/crypto/qce/cipher.h:34:8: warning: nested flexible arrays
      2 drivers/crypto/allwinner/sun8i-ss/sun8i-ss.h:151:8: warning: nested flexible arrays
      2 drivers/block/rnbd/rnbd-srv-dev.h:22:8: warning: nested flexible arrays
      2 crypto/chacha20poly1305.c:64:15: warning: nested flexible arrays
      2 crypto/adiantum.c:101:15: warning: nested flexible arrays
      2 ./include/sound/intel-nhlt.h:56:8: warning: nested flexible arrays
      2 ./include/scsi/fc_encode.h:25:8: warning: nested flexible arrays
      2 ./include/net/sctp/structs.h:334:8: warning: nested flexible arrays
      2 ./include/net/nfc/nci.h:518:8: warning: nested flexible arrays
      2 ./include/linux/sctp.h:390:8: warning: nested flexible arrays
      2 ./include/linux/mlx5/mlx5_ifc.h:7729:8: warning: nested flexible arrays
      2 ./include/linux/mlx5/mlx5_ifc.h:7494:8: warning: nested flexible arrays
      2 ./include/linux/mlx5/mlx5_ifc.h:6414:8: warning: nested flexible arrays
      2 ./include/linux/mlx5/mlx5_ifc.h:6367:8: warning: nested flexible arrays
      2 ./include/linux/mlx5/mlx5_ifc.h:5680:8: warning: nested flexible arrays
      2 ./include/linux/mlx5/mlx5_ifc.h:3863:8: warning: nested flexible arrays
      2 ./include/linux/mlx5/mlx5_ifc.h:3403:8: warning: nested flexible arrays
      2 ./include/linux/mlx5/mlx5_ifc.h:10373:8: warning: nested flexible arrays
      2 ./include/linux/hyperv.h:1055:8: warning: nested flexible arrays
      2 ./include/linux/efi.h:923:15: warning: nested flexible arrays
      2 ./include/linux/efi.h:922:8: warning: nested flexible arrays
      2 ./include/linux/ceph/osdmap.h:140:8: warning: nested flexible arrays
      2 ./include/crypto/cryptd.h:52:8: warning: nested flexible arrays
      2 ./include/crypto/cryptd.h:33:8: warning: nested flexible arrays
      2 ./include/crypto/cryptd.h:21:8: warning: nested flexible arrays
      2 ./include/asm-generic/hyperv-tlfs.h:403:8: warning: nested flexible arrays
      2 ./include/asm-generic/hyperv-tlfs.h:352:8: warning: nested flexible arrays
      2 ./drivers/net/wireless/intel/iwlwifi/mvm/..//fw/dbg.h:83:8: warning: nested flexible arrays
      1 sound/usb/misc/ua101.c:112:24: warning: nested flexible arrays
      1 sound/usb/hiface/pcm.c:24:8: warning: nested flexible arrays
      1 sound/usb/6fire/pcm.h:24:8: warning: nested flexible arrays
      1 sound/soc/intel/skylake/skl-i2s.h:80:8: warning: nested flexible arrays
      1 security/keys/trusted-keys/trusted_tpm1.c:37:8: warning: nested flexible arrays
      1 security/keys/dh.c:82:8: warning: nested flexible arrays
      1 security/integrity/ima/ima_template_lib.c:269:16: warning: nested flexible arrays
      1 security/integrity/ima/ima_main.c:752:16: warning: nested flexible arrays
      1 security/integrity/ima/ima_init.c:50:16: warning: nested flexible arrays
      1 security/integrity/ima/ima_api.c:220:16: warning: nested flexible arrays
      1 security/integrity/evm/../integrity.h:89:8: warning: nested flexible arrays
      1 net/sched/sch_taprio.c:84:8: warning: nested flexible arrays
      1 net/sched/sch_atm.c:64:8: warning: nested flexible arrays
      1 net/rxrpc/key.c:968:16: warning: nested flexible arrays
      1 net/nfc/nci/hci.c:53:8: warning: nested flexible arrays
      1 net/netfilter/nft_set_rbtree.c:25:8: warning: nested flexible arrays
      1 net/netfilter/nft_set_hash.c:417:8: warning: nested flexible arrays
      1 net/netfilter/nft_set_hash.c:29:8: warning: nested flexible arrays
      1 net/netfilter/nft_set_bitmap.c:15:8: warning: nested flexible arrays
      1 net/ipv4/esp4.c:26:8: warning: nested flexible arrays
      1 net/ipv4/ah4.c:18:8: warning: nested flexible arrays
      1 net/core/bpf_sk_storage.c:67:8: warning: nested flexible arrays
      1 net/ceph/auth_x_protocol.h:63:8: warning: nested flexible arrays
      1 net/bluetooth/rfcomm/tty.c:46:8: warning: nested flexible arrays
      1 net/bluetooth/mgmt_config.c:29:16: warning: nested flexible arrays
      1 net/bluetooth/l2cap_core.c:7985:16: warning: nested flexible arrays
      1 net/bluetooth/l2cap_core.c:5915:16: warning: nested flexible arrays
      1 net/bluetooth/l2cap_core.c:3930:16: warning: nested flexible arrays
      1 net/bluetooth/l2cap_core.c:1383:16: warning: nested flexible arrays
      1 net/bluetooth/l2cap_core.c:1382:8: warning: nested flexible arrays
      1 lib/crc-t10dif.c:65:16: warning: nested flexible arrays
      1 lib/bch.c:112:8: warning: nested flexible arrays
      1 kernel/events/core.c:7809:8: warning: nested flexible arrays
      1 kernel/bpf/bpf_struct_ops.c:29:8: warning: nested flexible arrays
      1 fs/ubifs/commit.c:497:8: warning: nested flexible arrays
      1 fs/ocfs2/xattr.c:53:8: warning: nested flexible arrays
      1 fs/jffs2/summary.h:140:7: warning: nested flexible arrays
      1 fs/dlm/user.c:58:16: warning: nested flexible arrays
      1 fs/dlm/user.c:52:8: warning: nested flexible arrays
      1 fs/dlm/requestqueue.c:18:8: warning: nested flexible arrays
      1 fs/dlm/midcomms.c:59:15: warning: nested flexible arrays
      1 fs/cifs/smb2pdu.h:899:8: warning: nested flexible arrays
      1 fs/cifs/smb2pdu.h:894:8: warning: nested flexible arrays
      1 fs/cifs/smb2pdu.h:886:8: warning: nested flexible arrays
      1 fs/cifs/smb2pdu.h:878:8: warning: nested flexible arrays
      1 fs/cifs/smb2pdu.h:864:8: warning: nested flexible arrays
      1 fs/cifs/smb2pdu.h:847:8: warning: nested flexible arrays
      1 fs/cifs/smb2pdu.h:830:8: warning: nested flexible arrays
      1 fs/cifs/smb2pdu.h:818:8: warning: nested flexible arrays
      1 fs/cifs/smb2pdu.h:811:8: warning: nested flexible arrays
      1 fs/cifs/smb2pdu.h:805:8: warning: nested flexible arrays
      1 fs/btrfs/send.c:44:15: warning: nested flexible arrays
      1 fs/btrfs/send.c:43:8: warning: nested flexible arrays
      1 drivers/w1/w1_netlink.c:216:16: warning: nested flexible arrays
      1 drivers/w1/w1_netlink.c:195:16: warning: nested flexible arrays
      1 drivers/usb/host/xhci-dbgcap.h:100:8: warning: nested flexible arrays
      1 drivers/usb/host/oxu210hp-hcd.c:396:8: warning: nested flexible arrays
      1 drivers/usb/host/ehci-fsl.c:419:8: warning: nested flexible arrays
      1 drivers/usb/gadget/function/uvc_configfs.c:858:8: warning: nested flexible arrays
      1 drivers/usb/gadget/function/u_serial.c:98:8: warning: nested flexible arrays
      1 drivers/usb/class/cdc-acm.h:83:8: warning: nested flexible arrays
      1 drivers/tty/synclinkmp.c:151:16: warning: nested flexible arrays
      1 drivers/tty/synclink_gt.c:238:8: warning: nested flexible arrays
      1 drivers/tty/synclink.c:178:8: warning: nested flexible arrays
      1 drivers/tty/serial/kgdb_nmi.c:90:8: warning: nested flexible arrays
      1 drivers/tty/serial/ifx6x60.h:56:8: warning: nested flexible arrays
      1 drivers/tty/rocket_int.h:1127:8: warning: nested flexible arrays
      1 drivers/tty/nozomi.c:318:8: warning: nested flexible arrays
      1 drivers/tty/n_gsm.c:125:8: warning: nested flexible arrays
      1 drivers/tty/mxser.c:220:8: warning: nested flexible arrays
      1 drivers/tty/moxa.c:129:8: warning: nested flexible arrays
      1 drivers/tty/isicom.c:198:9: warning: nested flexible arrays
      1 drivers/tty/ipwireless/tty.c:46:8: warning: nested flexible arrays
      1 drivers/tty/goldfish.c:36:8: warning: nested flexible arrays
      1 drivers/staging/rtl8192u/ieee80211/ieee80211.h:991:8: warning: nested flexible arrays
      1 drivers/staging/rtl8192u/ieee80211/ieee80211.h:971:8: warning: nested flexible arrays
      1 drivers/staging/rtl8192u/ieee80211/ieee80211.h:966:8: warning: nested flexible arrays
      1 drivers/staging/rtl8192u/ieee80211/ieee80211.h:957:8: warning: nested flexible arrays
      1 drivers/staging/rtl8192e/rtllib.h:846:8: warning: nested flexible arrays
      1 drivers/staging/rtl8192e/rtllib.h:838:8: warning: nested flexible arrays
      1 drivers/staging/rtl8192e/rtllib.h:818:8: warning: nested flexible arrays
      1 drivers/staging/rtl8192e/rtllib.h:813:8: warning: nested flexible arrays
      1 drivers/staging/rtl8192e/rtllib.h:808:8: warning: nested flexible arrays
      1 drivers/staging/rtl8192e/rtllib.h:799:8: warning: nested flexible arrays
      1 drivers/staging/rtl8192e/rtl8192e/../rtllib.h:846:8: warning: nested flexible arrays
      1 drivers/staging/rtl8192e/rtl8192e/../rtllib.h:824:8: warning: nested flexible arrays
      1 drivers/staging/ks7010/ks_hostif.h:211:8: warning: nested flexible arrays
      1 drivers/staging/greybus/uart.c:43:8: warning: nested flexible arrays
      1 drivers/staging/greybus/audio_apbridgea.h:99:8: warning: nested flexible arrays
      1 drivers/staging/greybus/audio_apbridgea.h:95:8: warning: nested flexible arrays
      1 drivers/staging/greybus/audio_apbridgea.h:90:8: warning: nested flexible arrays
      1 drivers/staging/greybus/audio_apbridgea.h:84:8: warning: nested flexible arrays
      1 drivers/staging/greybus/audio_apbridgea.h:78:8: warning: nested flexible arrays
      1 drivers/staging/greybus/audio_apbridgea.h:71:8: warning: nested flexible arrays
      1 drivers/staging/greybus/audio_apbridgea.h:129:8: warning: nested flexible arrays
      1 drivers/staging/greybus/audio_apbridgea.h:125:8: warning: nested flexible arrays
      1 drivers/staging/greybus/audio_apbridgea.h:121:8: warning: nested flexible arrays
      1 drivers/staging/greybus/audio_apbridgea.h:117:8: warning: nested flexible arrays
      1 drivers/staging/greybus/audio_apbridgea.h:112:8: warning: nested flexible arrays
      1 drivers/staging/greybus/audio_apbridgea.h:108:8: warning: nested flexible arrays
      1 drivers/staging/greybus/audio_apbridgea.h:104:8: warning: nested flexible arrays
      1 drivers/staging/gdm724x/gdm_tty.h:25:8: warning: nested flexible arrays
      1 drivers/staging/fwserial/fwserial.h:238:8: warning: nested flexible arrays
      1 drivers/staging/comedi/drivers/jr3_pci.c:93:7: warning: nested flexible arrays
      1 drivers/scsi/qla2xxx/qla_tmpl.h:76:24: warning: nested flexible arrays
      1 drivers/scsi/qla2xxx/qla_tmpl.h:66:17: warning: nested flexible arrays
      1 drivers/scsi/pmcraid.h:658:8: warning: nested flexible arrays
      1 drivers/scsi/pmcraid.h:630:8: warning: nested flexible arrays
      1 drivers/scsi/pm8001/pm80xx_hwi.h:556:8: warning: nested flexible arrays
      1 drivers/scsi/pm8001/pm8001_hwi.h:337:8: warning: nested flexible arrays
      1 drivers/scsi/ipr.h:1465:8: warning: nested flexible arrays
      1 drivers/rpmsg/qcom_glink_native.c:911:16: warning: nested flexible arrays
      1 drivers/rpmsg/qcom_glink_native.c:790:16: warning: nested flexible arrays
      1 drivers/rpmsg/qcom_glink_native.c:48:8: warning: nested flexible arrays
      1 drivers/rpmsg/qcom_glink_native.c:408:16: warning: nested flexible arrays
      1 drivers/rpmsg/qcom_glink_native.c:1266:16: warning: nested flexible arrays
      1 drivers/pci/controller/pci-hyperv.c:948:16: warning: nested flexible arrays
      1 drivers/pci/controller/pci-hyperv.c:451:8: warning: nested flexible arrays
      1 drivers/pci/controller/pci-hyperv.c:3237:16: warning: nested flexible arrays
      1 drivers/pci/controller/pci-hyperv.c:2294:16: warning: nested flexible arrays
      1 drivers/pci/controller/pci-hyperv.c:1930:16: warning: nested flexible arrays
      1 drivers/pci/controller/pci-hyperv.c:1370:16: warning: nested flexible arrays
      1 drivers/pci/controller/pci-hyperv.c:1117:16: warning: nested flexible arrays
      1 drivers/pci/controller/pci-hyperv.c:1028:16: warning: nested flexible arrays
      1 drivers/nvme/target/tcp.c:93:8: warning: nested flexible arrays
      1 drivers/nvme/target/tcp.c:55:8: warning: nested flexible arrays
      1 drivers/nvme/target/rdma.c:56:8: warning: nested flexible arrays
      1 drivers/nvme/target/loop.c:29:8: warning: nested flexible arrays
      1 drivers/nvme/target/loop.c:18:8: warning: nested flexible arrays
      1 drivers/nvme/target/fc.c:70:8: warning: nested flexible arrays
      1 drivers/nfc/pn533/usb.c:259:8: warning: nested flexible arrays
      1 drivers/nfc/pn533/usb.c:252:8: warning: nested flexible arrays
      1 drivers/net/wireless/wl3501.h:426:8: warning: nested flexible arrays
      1 drivers/net/wireless/wl3501.h:266:8: warning: nested flexible arrays
      1 drivers/net/wireless/wl3501.h:258:8: warning: nested flexible arrays
      1 drivers/net/wireless/wl3501.h:253:8: warning: nested flexible arrays
      1 drivers/net/wireless/wl3501.h:248:8: warning: nested flexible arrays
      1 drivers/net/wireless/wl3501.h:237:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/wl12xx_80211.h:133:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/scan.h:125:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:696:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:685:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:681:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:677:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:656:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:647:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:634:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:599:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:583:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:563:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:554:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:539:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:464:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:431:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:395:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:386:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:378:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:288:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:265:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:257:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/cmd.h:217:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:944:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:930:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:919:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:901:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:878:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:822:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:810:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:801:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:788:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:773:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:760:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:741:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:718:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:689:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:664:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:644:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:629:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:584:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:566:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:558:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:546:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:529:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:518:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:458:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:452:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:446:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:434:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:424:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:417:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:402:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:385:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:369:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:360:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:352:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:343:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:327:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:312:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:303:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:295:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:287:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:280:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:271:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:262:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:213:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:205:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:195:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:185:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:172:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:153:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wlcore/acx.h:115:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/scan.h:97:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/scan.h:34:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/cmd.h:63:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/cmd.h:55:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/cmd.h:48:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/cmd.h:40:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/cmd.h:34:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/cmd.h:14:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/acx.h:73:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/acx.h:48:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/acx.h:382:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/acx.h:373:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/acx.h:349:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/acx.h:344:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/acx.h:335:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/acx.h:307:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/acx.h:294:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl18xx/acx.h:285:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl12xx/scan.h:67:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl12xx/scan.h:56:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl12xx/scan.h:110:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl12xx/scan.h:102:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl12xx/cmd.h:92:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl12xx/cmd.h:82:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl12xx/cmd.h:63:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl12xx/cmd.h:47:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl12xx/cmd.h:32:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl12xx/cmd.h:17:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl12xx/acx.h:29:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl12xx/../wlcore/scan.h:53:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl12xx/../wlcore/acx.h:474:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/wl12xx_80211.h:144:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/wl12xx_80211.h:136:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/wl12xx_80211.h:131:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/wl12xx_80211.h:108:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/cmd.h:96:9: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/cmd.h:377:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/cmd.h:328:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/cmd.h:312:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/cmd.h:300:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/cmd.h:280:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/cmd.h:271:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/cmd.h:234:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/cmd.h:216:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/cmd.h:138:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:89:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:848:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:832:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:817:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:809:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:790:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:783:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:776:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:769:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:762:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:752:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:711:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:697:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:683:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:555:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:510:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:49:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:496:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:485:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:431:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:402:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:381:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:359:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:342:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:330:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:314:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:301:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:267:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:176:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:1292:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:1235:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:122:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:1224:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:1201:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:1180:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:1145:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:1137:8: warning: nested flexible arrays
      1 drivers/net/wireless/ti/wl1251/acx.h:1088:8: warning: nested flexible arrays
      1 drivers/net/wireless/rndis_wlan.c:209:15: warning: nested flexible arrays
      1 drivers/net/wireless/rndis_wlan.c:207:8: warning: nested flexible arrays
      1 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h:1405:8: warning: nested flexible arrays
      1 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h:1399:8: warning: nested flexible arrays
      1 drivers/net/wireless/quantenna/qtnfmac/qlink.h:1680:8: warning: nested flexible arrays
      1 drivers/net/wireless/quantenna/qtnfmac/qlink.h:1659:8: warning: nested flexible arrays
      1 drivers/net/wireless/quantenna/qtnfmac/qlink.h:1620:8: warning: nested flexible arrays
      1 drivers/net/wireless/quantenna/qtnfmac/qlink.h:1608:8: warning: nested flexible arrays
      1 drivers/net/wireless/microchip/wilc1000/spi.c:50:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:4499:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:4213:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:4203:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:4067:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3957:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3862:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3782:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3753:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3668:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3644:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3603:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3561:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3530:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3499:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3414:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3385:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3355:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3316:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3280:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3208:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3139:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3051:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:3010:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:2985:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:2955:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:2922:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:2863:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:2829:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:2768:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:2726:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:2667:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:2590:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:2496:8: warning: nested flexible arrays
      1 drivers/net/wireless/marvell/mwl8k.c:2347:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/iwlwifi/mvm/d3.c:1465:24: warning: nested flexible arrays
      1 drivers/net/wireless/intel/iwlwifi/fw/dbg.h:83:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/iwlwifi/fw/api/dbg-tlv.h:270:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/iwlwifi/dvm/commands.h:2473:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/iwlwifi/dvm/commands.h:2344:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/iwlegacy/common.h:521:15: warning: nested flexible arrays
      1 drivers/net/wireless/intel/iwlegacy/common.h:520:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/iwlegacy/commands.h:2670:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/iwlegacy/commands.h:2526:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/iwlegacy/commands.h:2482:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/ipw2x00/libipw.h:469:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/ipw2x00/libipw.h:442:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/ipw2x00/libipw.h:434:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/ipw2x00/libipw.h:420:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/ipw2x00/libipw.h:403:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/ipw2x00/ipw2200.h:690:15: warning: nested flexible arrays
      1 drivers/net/wireless/intel/ipw2x00/ipw2200.h:688:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/ipw2x00/ipw2200.h:505:15: warning: nested flexible arrays
      1 drivers/net/wireless/intel/ipw2x00/ipw2200.h:503:8: warning: nested flexible arrays
      1 drivers/net/wireless/intel/ipw2x00/ipw2100.h:786:15: warning: nested flexible arrays
      1 drivers/net/wireless/intel/ipw2x00/ipw2100.h:785:8: warning: nested flexible arrays
      1 drivers/net/wireless/ath/wil6210/wmi.c:4024:16: warning: nested flexible arrays
      1 drivers/net/wireless/ath/wil6210/wmi.c:2761:16: warning: nested flexible arrays
      1 drivers/net/wireless/ath/wil6210/main.c:467:16: warning: nested flexible arrays
      1 drivers/net/wireless/ath/wil6210/cfg80211.c:871:16: warning: nested flexible arrays
      1 drivers/net/wireless/ath/ath10k/htt.h:1791:8: warning: nested flexible arrays
      1 drivers/net/usb/hso.c:195:8: warning: nested flexible arrays
      1 drivers/net/ethernet/sfc/vfdi.h:162:8: warning: nested flexible arrays
      1 drivers/net/ethernet/netronome/nfp/nfp_net_debugdump.c:91:8: warning: nested flexible arrays
      1 drivers/net/ethernet/netronome/nfp/nfp_net_debugdump.c:86:8: warning: nested flexible arrays
      1 drivers/net/ethernet/netronome/nfp/nfp_net_debugdump.c:77:8: warning: nested flexible arrays
      1 drivers/net/ethernet/netronome/nfp/nfp_net_debugdump.c:69:8: warning: nested flexible arrays
      1 drivers/net/ethernet/netronome/nfp/nfp_net_debugdump.c:63:8: warning: nested flexible arrays
      1 drivers/net/ethernet/netronome/nfp/nfp_net_debugdump.c:57:8: warning: nested flexible arrays
      1 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c:23:8: warning: nested flexible arrays
      1 drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.c:133:8: warning: nested flexible arrays
      1 drivers/net/ethernet/mellanox/mlx5/core/en_accel/tls.h:75:8: warning: nested flexible arrays
      1 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h:246:15: warning: nested flexible arrays
      1 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h:244:8: warning: nested flexible arrays
      1 drivers/net/ethernet/intel/ice/ice_adminq_cmd.h:654:8: warning: nested flexible arrays
      1 drivers/mmc/host/vub300.c:296:8: warning: nested flexible arrays
      1 drivers/mmc/host/vub300.c:153:7: warning: nested flexible arrays
      1 drivers/mmc/core/sdio_uart.c:63:8: warning: nested flexible arrays
      1 drivers/media/usb/siano/smsusb.c:38:8: warning: nested flexible arrays
      1 drivers/md/raid5-ppl.c:135:8: warning: nested flexible arrays
      1 drivers/md/raid5-cache.c:82:8: warning: nested flexible arrays
      1 drivers/md/md-multipath.h:25:8: warning: nested flexible arrays
      1 drivers/md/dm-writecache.c:195:8: warning: nested flexible arrays
      1 drivers/md/dm-thin.c:229:8: warning: nested flexible arrays
      1 drivers/md/dm-clone-target.c:69:8: warning: nested flexible arrays
      1 drivers/md/bcache/writeback.c:761:8: warning: nested flexible arrays
      1 drivers/md/bcache/writeback.c:245:8: warning: nested flexible arrays
      1 drivers/md/bcache/super.c:481:9: warning: nested flexible arrays
      1 drivers/md/bcache/extents.c:427:33: warning: nested flexible arrays
      1 drivers/md/bcache/debug.c:159:8: warning: nested flexible arrays
      1 drivers/md/bcache/btree.c:340:9: warning: nested flexible arrays
      1 drivers/md/bcache/btree.c:2175:25: warning: nested flexible arrays
      1 drivers/md/bcache/btree.c:1089:9: warning: nested flexible arrays
      1 drivers/md/bcache/bset.c:1196:9: warning: nested flexible arrays
      1 drivers/md/bcache/alloc.c:621:9: warning: nested flexible arrays
      1 drivers/md/bcache/alloc.c:544:9: warning: nested flexible arrays
      1 drivers/md/bcache/alloc.c:540:8: warning: nested flexible arrays
      1 drivers/isdn/capi/capi.c:82:8: warning: nested flexible arrays
      1 drivers/ipack/devices/ipoctal.c:30:8: warning: nested flexible arrays
      1 drivers/input/keyboard/applespi.c:296:15: warning: nested flexible arrays
      1 drivers/input/keyboard/applespi.c:290:8: warning: nested flexible arrays
      1 drivers/infiniband/hw/mlx5/devx.c:42:8: warning: nested flexible arrays
      1 drivers/infiniband/hw/mlx5/devx.c:32:8: warning: nested flexible arrays
      1 drivers/infiniband/hw/hfi1/mad.c:63:8: warning: nested flexible arrays
      1 drivers/infiniband/hw/hfi1/firmware.c:149:8: warning: nested flexible arrays
      1 drivers/infiniband/core/uverbs_std_types_flow_action.c:218:8: warning: nested flexible arrays
      1 drivers/infiniband/core/cm.c:238:8: warning: nested flexible arrays
      1 drivers/hwspinlock/stm32_hwspinlock.c:23:8: warning: nested flexible arrays
      1 drivers/hwspinlock/sprd_hwspinlock.c:35:8: warning: nested flexible arrays
      1 drivers/hwspinlock/sirf_hwspinlock.c:21:8: warning: nested flexible arrays
      1 drivers/hv/vmbus_drv.c:1023:8: warning: nested flexible arrays
      1 drivers/gpu/drm/xlnx/zynqmp_disp.c:120:8: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/subdev/mmu/uvmm.c:78:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/subdev/mmu/uvmm.c:377:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/subdev/mmu/uvmm.c:155:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/subdev/mmu/ummu.c:109:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/subdev/mmu/umem.c:147:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/engine/disp/rootnv50.c:136:23: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/engine/device/user.c:109:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/core/ioctl.c:86:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/core/ioctl.c:53:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/core/ioctl.c:433:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/core/ioctl.c:300:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/core/ioctl.c:257:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/core/ioctl.c:168:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/core/client.c:76:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/core/client.c:71:8: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/core/client.c:194:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvkm/core/client.c:133:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvif/object.c:34:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvif/object.c:247:16: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvif/object.c:171:16: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvif/object.c:124:16: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvif/object.c:105:16: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvif/notify.c:67:16: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvif/notify.c:36:16: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvif/notify.c:148:16: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvif/notify.c:115:21: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvif/fifo.c:74:16: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvif/fifo.c:28:16: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nvif/client.c:66:16: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nouveau_usif.c:76:21: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nouveau_usif.c:35:8: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nouveau_usif.c:300:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nouveau_usif.c:268:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nouveau_usif.c:129:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nouveau_usif.c:126:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nouveau_svm.c:625:16: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nouveau_nvif.c:77:21: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nouveau_chan.c:550:16: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/nouveau_abi16.c:370:15: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/dispnv50/disp.c:676:24: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/dispnv50/disp.c:675:25: warning: nested flexible arrays
      1 drivers/gpu/drm/nouveau/dispnv50/disp.c:646:16: warning: nested flexible arrays
      1 drivers/gpu/drm/i915/gvt/opregion.c:116:8: warning: nested flexible arrays
      1 drivers/gpu/drm/amd/amdgpu/si_dpm.h:958:8: warning: nested flexible arrays
      1 drivers/gpu/drm/amd/amdgpu/si_dpm.h:818:8: warning: nested flexible arrays
      1 drivers/crypto/sa2ul.h:326:8: warning: nested flexible arrays
      1 drivers/crypto/picoxcell_crypto.c:79:8: warning: nested flexible arrays
      1 drivers/crypto/padlock-sha.c:23:8: warning: nested flexible arrays
      1 drivers/crypto/marvell/octeontx/otx_cptvf_algs.h:165:8: warning: nested flexible arrays
      1 drivers/crypto/img-hash.c:82:8: warning: nested flexible arrays
      1 drivers/crypto/chelsio/chtls/chtls_io.c:162:16: warning: nested flexible arrays
      1 drivers/crypto/chelsio/chcr_ktls.h:67:8: warning: nested flexible arrays
      1 drivers/crypto/chelsio/chcr_crypto.h:293:8: warning: nested flexible arrays
      1 drivers/crypto/chelsio/chcr_core.h:172:8: warning: nested flexible arrays
      1 drivers/crypto/chelsio/chcr_core.h:165:8: warning: nested flexible arrays
      1 drivers/crypto/chelsio/chcr_core.h:137:8: warning: nested flexible arrays
      1 drivers/crypto/atmel-aes.c:161:8: warning: nested flexible arrays
      1 drivers/crypto/amlogic/amlogic-gxl.h:109:8: warning: nested flexible arrays
      1 drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h:188:8: warning: nested flexible arrays
      1 drivers/clk/sifive/fu540-prci.c:145:8: warning: nested flexible arrays
      1 drivers/clk/samsung/clk-exynos5433.c:5499:8: warning: nested flexible arrays
      1 drivers/clk/clk-bm1880.c:62:8: warning: nested flexible arrays
      1 drivers/clk/bcm/clk-bcm63xx-gate.c:23:8: warning: nested flexible arrays
      1 drivers/clk/bcm/clk-bcm2835.c:313:8: warning: nested flexible arrays
      1 drivers/char/ttyprintk.c:20:8: warning: nested flexible arrays
      1 drivers/char/pcmcia/synclink_cs.c:137:16: warning: nested flexible arrays
      1 drivers/char/../tty/hvc/hvc_console.h:35:8: warning: nested flexible arrays
      1 drivers/acpi/nfit/intel.c:719:16: warning: nested flexible arrays
      1 drivers/acpi/nfit/intel.c:613:16: warning: nested flexible arrays
      1 drivers/acpi/nfit/intel.c:57:16: warning: nested flexible arrays
      1 drivers/acpi/nfit/intel.c:549:16: warning: nested flexible arrays
      1 drivers/acpi/nfit/intel.c:438:16: warning: nested flexible arrays
      1 drivers/acpi/nfit/intel.c:367:16: warning: nested flexible arrays
      1 drivers/acpi/nfit/intel.c:329:16: warning: nested flexible arrays
      1 drivers/acpi/nfit/intel.c:284:16: warning: nested flexible arrays
      1 drivers/acpi/nfit/intel.c:241:16: warning: nested flexible arrays
      1 drivers/acpi/nfit/intel.c:199:16: warning: nested flexible arrays
      1 drivers/acpi/nfit/intel.c:155:16: warning: nested flexible arrays
      1 drivers/acpi/nfit/intel.c:122:16: warning: nested flexible arrays
      1 crypto/xts.c:33:8: warning: nested flexible arrays
      1 crypto/lrw.c:52:8: warning: nested flexible arrays
      1 crypto/essiv.c:59:8: warning: nested flexible arrays
      1 crypto/cts.c:59:8: warning: nested flexible arrays
      1 crypto/cryptd.c:79:8: warning: nested flexible arrays
      1 crypto/chacha20poly1305.c:51:8: warning: nested flexible arrays
      1 crypto/chacha20poly1305.c:45:8: warning: nested flexible arrays
      1 crypto/chacha20poly1305.c:33:8: warning: nested flexible arrays
      1 crypto/algif_hash.c:19:8: warning: nested flexible arrays
      1 crypto/adiantum.c:76:8: warning: nested flexible arrays
      1 crypto/adiantum.c:120:16: warning: nested flexible arrays
      1 ./include/uapi/linux/wmi.h:40:8: warning: nested flexible arrays
      1 ./include/uapi/linux/sctp.h:633:7: warning: nested flexible arrays
      1 ./include/uapi/linux/fuse.h:817:8: warning: nested flexible arrays
      1 ./include/sound/sof/ext_manifest.h:82:8: warning: nested flexible arrays
      1 ./include/rdma/ib_verbs.h:2121:8: warning: nested flexible arrays
      1 ./include/net/tls.h:99:8: warning: nested flexible arrays
      1 ./include/net/netfilter/nf_conntrack_timeout.h:20:8: warning: nested flexible arrays
      1 ./include/linux/sctp.h:617:8: warning: nested flexible arrays
      1 ./include/linux/sctp.h:600:8: warning: nested flexible arrays
      1 ./include/linux/sctp.h:442:8: warning: nested flexible arrays
      1 ./include/linux/sctp.h:345:8: warning: nested flexible arrays
      1 ./include/linux/mlx5/mlx5_ifc.h:5049:8: warning: nested flexible arrays
      1 ./include/linux/mlx5/mlx5_ifc.h:4838:8: warning: nested flexible arrays
      1 ./include/linux/mlx5/mlx5_ifc.h:4683:8: warning: nested flexible arrays
      1 ./include/linux/mlx5/mlx5_ifc.h:4352:8: warning: nested flexible arrays
      1 ./include/linux/mlx5/mlx5_ifc.h:1980:8: warning: nested flexible arrays
      1 ./include/linux/greybus/greybus_protocols.h:2018:8: warning: nested flexible arrays
      1 ./include/linux/greybus/greybus_protocols.h:2002:15: warning: nested flexible arrays
      1 ./include/linux/greybus/greybus_protocols.h:1999:8: warning: nested flexible arrays
      1 ./include/linux/cyclades.h:119:8: warning: nested flexible arrays
      1 ./include/asm-generic/hyperv-tlfs.h:440:8: warning: nested flexible arrays
      1 ./include/asm-generic/hyperv-tlfs.h:434:15: warning: nested flexible arrays
      1 ./include/asm-generic/hyperv-tlfs.h:431:8: warning: nested flexible arrays
      1 ./drivers/net/wireless/intel/iwlwifi/mvm/..//fw/api/tx.h:801:8: warning: nested flexible arrays
      1 ./drivers/net/wireless/intel/iwlwifi/mvm/..//fw/api/tx.h:782:8: warning: nested flexible arrays
      1 ./drivers/net/wireless/intel/iwlwifi/mvm/..//fw/api/tdls.h:184:8: warning: nested flexible arrays
      1 ./drivers/net/wireless/intel/iwlwifi/mvm/..//fw/api/tdls.h:137:8: warning: nested flexible arrays
      1 ./drivers/net/wireless/intel/iwlwifi/mvm/..//fw/api/tdls.h:121:8: warning: nested flexible arrays
      1 ./drivers/net/wireless/intel/iwlwifi/mvm/..//fw/api/tdls.h:109:8: warning: nested flexible arrays
      1 ./drivers/net/wireless/intel/iwlwifi/mvm/..//fw/api/scan.h:820:8: warning: nested flexible arrays
Luc Van Oostenryck Oct. 1, 2020, 7:51 p.m. UTC | #5 
On Thu, Oct 01, 2020 at 09:41:21PM +0200, Luc Van Oostenryck wrote:
> On Thu, Oct 01, 2020 at 12:27:56PM -0700, Linus Torvalds wrote:
> > On Thu, Oct 1, 2020 at 12:17 PM Luc Van Oostenryck
> > <luc.vanoostenryck@gmail.com> wrote:
> > >
> > > > So in the kernel, we would
> > > >
> > > >  - start warning about 'sizeof(flex_struct)'
> > >
> > > Adding this warning by default annoys me slightly because it will
> > > add 5700+ warnings to the 18000 already present and I think sparse
> > > is already underused because it is very/too noisy. But I guess that
> > > most occurrences come from a few macros and thus should be easy to
> > > get rid off.
> > 
> > Hopefully. I'll try to take a look. Do you have the sparse changes in
> > a git branch already so that I can just try that directly?
> 
> What I posted yesterday is on
> 	git://git.kernel.org/pub/scm/devel/sparse/sparse-dev.git flex-array
> 
> > Or if you send me a couple of examples, maybe it's just the same
> > pattern over and over,..
> 
> Well, the 888 occurences I see are already 'unique' occurences
> (in the sense that the warning is from a distinct file+position).
> I'm adding in attachment the extract of my test logs (but it is
> on v5.9-rc1 so it's maybe not much usefull). I ddn't investigated
> anything, just checked a few case to see that it was a genuine
> occurrence.

Sorry, I was thinking about the nested ones and sent the wrong.
Here are the top entries for sizeof():
     66 ./include/linux/filter.h:752:16: warning: using sizeof on a flexible structure
     48 crypto/gcm.c:547:17: warning: using sizeof on a flexible structure
     48 crypto/authencesn.c:357:17: warning: using sizeof on a flexible structure
     48 crypto/authenc.c:339:17: warning: using sizeof on a flexible structure
     44 ./include/linux/ihex.h:26:38: warning: using sizeof on a flexible structure
     30 drivers/crypto/chelsio/chcr_algo.c:793:32: warning: using sizeof on a flexible structure
     29 ./include/crypto/skcipher.h:518:31: warning: using sizeof on a flexible structure
     27 ./include/linux/can/dev.h:100:13: warning: using sizeof on a flexible structure
     24 net/mac80211/tdls.c:874:32: warning: using sizeof on a flexible structure
     24 net/ipv6/ndisc.c:1662:18: warning: using sizeof on a flexible structure
     24 drivers/tty/tty_buffer.c:352:28: warning: using sizeof on a flexible structure
     24 drivers/tty/tty_buffer.c:316:28: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:972:25: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:968:32: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:961:29: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:905:25: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:897:29: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:760:49: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:756:55: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:747:62: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:738:49: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:729:53: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:577:33: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:559:39: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:554:41: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:404:29: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:1134:33: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:1118:55: warning: using sizeof on a flexible structure
     23 net/netfilter/ipset/ip_set_hash_gen.h:1114:51: warning: using sizeof on a flexible structure
     20 fs/proc/inode.c:110:9: warning: using sizeof on a flexible structure
     20 fs/proc/inode.c:109:17: warning: using sizeof on a flexible structure
     20 fs/proc/generic.c:425:29: warning: using sizeof on a flexible structure
     18 net/ipv4/tcp_output.c:1241:28: warning: using sizeof on a flexible structure
     18 net/core/net-sysfs.c:769:23: warning: using sizeof on a flexible structure
     17 ./include/linux/ihex.h:52:50: warning: using sizeof on a flexible structure
     16 fs/proc/inode.c:107:35: warning: using sizeof on a flexible structure
     16 ./include/crypto/skcipher.h:496:23: warning: using sizeof on a flexible structure
     15 mm/percpu.c:2259:21: warning: using sizeof on a flexible structure
     14 drivers/net/ethernet/chelsio/cxgb4/cudbg_lib.h:281:27: warning: using sizeof on a flexible structure
     13 drivers/net/wireguard/messages.h:117:34: warning: using sizeof on a flexible structure
     13 ./include/crypto/hash.h:594:23: warning: using sizeof on a flexible structure
     12 net/netfilter/x_tables.c:780:21: warning: using sizeof on a flexible structure
     12 net/netfilter/x_tables.c:1157:21: warning: using sizeof on a flexible structure
     12 net/netfilter/ipset/ip_set_hash_gen.h:143:51: warning: using sizeof on a flexible structure
     12 net/netfilter/ipset/ip_set_hash_gen.h:139:29: warning: using sizeof on a flexible structure
     12 net/mac80211/iface.c:1829:28: warning: using sizeof on a flexible structure
     12 net/core/skbuff.c:6188:26: warning: using sizeof on a flexible structure
     12 net/core/skbuff.c:6146:39: warning: using sizeof on a flexible structure
     12 net/core/skbuff.c:4214:16: warning: using sizeof on a flexible structure
     12 net/core/bpf_sk_storage.c:666:32: warning: using sizeof on a flexible structure
     12 net/core/bpf_sk_storage.c:1081:9: warning: using sizeof on a flexible structure
     12 kernel/module.c:1601:19: warning: using sizeof on a flexible structure
     12 kernel/bpf/core.c:881:16: warning: using sizeof on a flexible structure
     12 drivers/staging/greybus/sdio.c:136:20: warning: using sizeof on a flexible structure
     12 drivers/infiniband/hw/cxgb4/provider.c:278:31: warning: using sizeof on a flexible structure
     12 drivers/gpu/drm/drm_managed.c:92:13: warning: using sizeof on a flexible structure
     12 drivers/crypto/picoxcell_crypto.c:711:17: warning: using sizeof on a flexible structure
     12 crypto/cmac.c:271:17: warning: using sizeof on a flexible structure
     12 crypto/cmac.c:266:17: warning: using sizeof on a flexible structure
     12 crypto/chacha20poly1305.c:528:17: warning: using sizeof on a flexible structure
     12 crypto/adiantum.c:429:23: warning: using sizeof on a flexible structure
     11 ./include/uapi/linux/bcache.h:101:17: warning: using sizeof on a flexible structure
     11 ./include/crypto/aead.h:414:23: warning: using sizeof on a flexible structure
     10 drivers/infiniband/sw/rxe/rxe.h:76:9: warning: using sizeof on a flexible structure
     10 drivers/base/devres.c:95:13: warning: using sizeof on a flexible structure
     10 ./include/rdma/rdmavt_qp.h:535:39: warning: using sizeof on a flexible structure
     10 ./include/rdma/ib_verbs.h:583:25: warning: using sizeof on a flexible structure
     10 ./include/crypto/hash.h:990:26: warning: using sizeof on a flexible structure
     10 ./include/crypto/akcipher.h:196:23: warning: using sizeof on a flexible structure

Less frequent ones removed. There is a lot with a single occurence
mostly in drivers/.


-- Luc
diff mbox series

Patch

diff --git a/options.c b/options.c
index b46900b973a6..92d64e6ab64e 100644
--- a/options.c
+++ b/options.c
@@ -102,6 +102,7 @@  int Wenum_mismatch = 1;
 int Wexternal_function_has_definition = 1;
 int Wflexible_array_array = 1;
 int Wflexible_array_nested = 0;
+int Wflexible_array_padding = 0;
 int Wflexible_array_sizeof = 0;
 int Wimplicit_int = 1;
 int Winit_cstring = 0;
@@ -845,6 +846,7 @@  static const struct flag warnings[] = {
 	{ "external-function-has-definition", &Wexternal_function_has_definition },
 	{ "flexible-array-array", &Wflexible_array_array },
 	{ "flexible-array-nested", &Wflexible_array_nested },
+	{ "flexible-array-padding", &Wflexible_array_padding },
 	{ "flexible-array-sizeof", &Wflexible_array_sizeof },
 	{ "implicit-int", &Wimplicit_int },
 	{ "init-cstring", &Winit_cstring },
diff --git a/options.h b/options.h
index d23ed472eaac..31d9c5859977 100644
--- a/options.h
+++ b/options.h
@@ -101,6 +101,7 @@  extern int Wenum_mismatch;
 extern int Wexternal_function_has_definition;
 extern int Wflexible_array_array;
 extern int Wflexible_array_nested;
+extern int Wflexible_array_padding;
 extern int Wflexible_array_sizeof;
 extern int Wimplicit_int;
 extern int Winit_cstring;
diff --git a/sparse.1 b/sparse.1
index 9b1a59c6b9d4..8c61e869dc57 100644
--- a/sparse.1
+++ b/sparse.1
@@ -268,6 +268,12 @@  Sparse issues these warnings by default. To turn them off, use
 Warn about structures containing a flexible array being contained into
 another structure, union or array.
 
+Sparse does not issue these warnings by default.
+.
+.TP
+.B -Wflexible-array-padding
+Warn about padding alignments caused by the presence of a flexible array member.
+
 Sparse does not issue these warnings by default.
 .
 .TP
diff --git a/symbol.c b/symbol.c
index a9f646eb053f..eabb2226651f 100644
--- a/symbol.c
+++ b/symbol.c
@@ -213,6 +213,8 @@  static struct symbol * examine_struct_union_type(struct symbol *sym, int advance
 	}
 	if (info.flex_array) {
 		info.has_flex_array = 1;
+		if (sym->offset != bits_to_bytes(bit_size) && Wflexible_array_padding)
+			warning(info.flex_array->pos, "flexible array member has padding");
 	}
 	if (info.has_flex_array)
 		sym->has_flex_array = 1;
diff --git a/validation/flex-array-padding.c b/validation/flex-array-padding.c
index 2ba77971266e..95b349e1199a 100644
--- a/validation/flex-array-padding.c
+++ b/validation/flex-array-padding.c
@@ -12,7 +12,6 @@  static int foo(struct s *s)
 /*
  * check-name: flex-array-padding
  * check-command: test-linearize -Wflexible-array-padding $file
- * check-known-to-fail
  *
  * check-output-ignore
  *