The following changes since commit 8f3d9f354286745c751374f5f1fcafee6b3f3136:
Linux 5.7-rc1 (2020-04-12 12:35:55 -0700)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git tags/flexible-array-member-5.7-rc2
for you to fetch changes up to 43951585e1308b322c8ee31a4aafd08213f5c5d7:
xattr.h: Replace zero-length array with flexible-array member (2020-04-18 15:44:56 -0500)
----------------------------------------------------------------
flexible-array member convertion patches for 5.7-rc2
Hi Linus,
Please, pull the following patches that replace zero-length arrays with
flexible-array members.
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member convertions) will also
help to get completely rid of those sorts of issues.
Notice that all of these patches have been baking in linux-next for
quite a while now and, 238 more of these patches have already been
merged into 5.7-rc1.
There are a couple hundred more of these issues waiting to be addressed
in the whole codebase.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Thanks
----------------------------------------------------------------
Gustavo A. R. Silva (28):
bio: Replace zero-length array with flexible-array member
blk-mq: Replace zero-length array with flexible-array member
blk_types: Replace zero-length array with flexible-array member
can: dev: peak_canfd.h: Replace zero-length array with flexible-array member
digsig.h: Replace zero-length array with flexible-array member
dirent.h: Replace zero-length array with flexible-array member
enclosure.h: Replace zero-length array with flexible-array member
energy_model.h: Replace zero-length array with flexible-array member
ethtool.h: Replace zero-length array with flexible-array member
genalloc.h: Replace zero-length array with flexible-array member
igmp.h: Replace zero-length array with flexible-array member
ihex.h: Replace zero-length array with flexible-array member
irq.h: Replace zero-length array with flexible-array member
lib: cpu_rmap: Replace zero-length array with flexible-array member
list_lru.h: Replace zero-length array with flexible-array member
memcontrol.h: Replace zero-length array with flexible-array member
platform_data: wilco-ec.h: Replace zero-length array with flexible-array member
posix_acl.h: Replace zero-length array with flexible-array member
rio.h: Replace zero-length array with flexible-array member
rslib.h: Replace zero-length array with flexible-array member
sched: topology.h: Replace zero-length array with flexible-array member
skbuff.h: Replace zero-length array with flexible-array member
swap.h: Replace zero-length array with flexible-array member
ti_wilink_st.h: Replace zero-length array with flexible-array member
tpm_eventlog.h: Replace zero-length array with flexible-array member
uapi: linux: dlm_device.h: Replace zero-length array with flexible-array member
uapi: linux: fiemap.h: Replace zero-length array with flexible-array member
xattr.h: Replace zero-length array with flexible-array member
include/linux/bio.h | 2 +-
include/linux/blk-mq.h | 2 +-
include/linux/blk_types.h | 2 +-
include/linux/can/dev/peak_canfd.h | 4 ++--
include/linux/cpu_rmap.h | 2 +-
include/linux/digsig.h | 4 ++--
include/linux/dirent.h | 2 +-
include/linux/enclosure.h | 2 +-
include/linux/energy_model.h | 2 +-
include/linux/ethtool.h | 4 ++--
include/linux/genalloc.h | 2 +-
include/linux/igmp.h | 2 +-
include/linux/ihex.h | 2 +-
include/linux/irq.h | 4 ++--
include/linux/list_lru.h | 2 +-
include/linux/memcontrol.h | 4 ++--
include/linux/platform_data/wilco-ec.h | 2 +-
include/linux/posix_acl.h | 2 +-
include/linux/rio.h | 4 ++--
include/linux/rslib.h | 2 +-
include/linux/sched/topology.h | 2 +-
include/linux/skbuff.h | 2 +-
include/linux/swap.h | 2 +-
include/linux/ti_wilink_st.h | 6 +++---
include/linux/tpm_eventlog.h | 6 +++---
include/linux/xattr.h | 2 +-
include/uapi/linux/dlm_device.h | 4 ++--
include/uapi/linux/fiemap.h | 2 +-
28 files changed, 39 insertions(+), 39 deletions(-)
The pull request you sent on Sat, 18 Apr 2020 16:38:28 -0500:
> git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git tags/flexible-array-member-5.7-rc2
has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/13402837414070492004cd0a9c80b5fcebbd1a9e
Thank you!
--
Deet-doot-dot, I am a bot.
https://korg.wiki.kernel.org/userdoc/prtracker
Hi Gustavo,
On Sat, 18 Apr 2020 16:38:28 -0500 "Gustavo A. R. Silva" <[email protected]> wrote:
>
> Notice that all of these patches have been baking in linux-next for
> quite a while now and, 238 more of these patches have already been
> merged into 5.7-rc1.
Except that you rebased these just yesterday :-(
I understand why you did that (because there are still three earlier
patches in the linux-next version of this tree), but please try to
avoid this in the future.
Also, please clean up your linux-next included branch to avoid
conflicts in the future, thanks.
--
Cheers,
Stephen Rothwell
Hi Stephen,
On 4/19/20 20:12, Stephen Rothwell wrote:
> Hi Gustavo,
>
> On Sat, 18 Apr 2020 16:38:28 -0500 "Gustavo A. R. Silva" <[email protected]> wrote:
>>
>> Notice that all of these patches have been baking in linux-next for
>> quite a while now and, 238 more of these patches have already been
>> merged into 5.7-rc1.
>
> Except that you rebased these just yesterday :-(
>
> I understand why you did that (because there are still three earlier
> patches in the linux-next version of this tree), but please try to
> avoid this in the future.
>
That's correct. I'm sorry for any trouble that may have caused you.
I will try to avoid doing that in the future.
> Also, please clean up your linux-next included branch to avoid
> conflicts in the future, thanks.
>
Done! :)
Thanks
--
Gustavo