diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-04-19 19:34:30 +0200 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-04-19 19:34:30 +0200 |
commit | 13402837414070492004cd0a9c80b5fcebbd1a9e (patch) | |
tree | 28b9e34473ebb996455d572f55e8d6ffe72a3cb1 /include/uapi | |
parent | Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/... (diff) | |
parent | xattr.h: Replace zero-length array with flexible-array member (diff) | |
download | linux-13402837414070492004cd0a9c80b5fcebbd1a9e.tar.xz linux-13402837414070492004cd0a9c80b5fcebbd1a9e.zip |
Merge tag 'flexible-array-member-5.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux
Pull flexible-array member conversion from Gustavo Silva:
"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")
* tag 'flexible-array-member-5.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (28 commits)
xattr.h: Replace zero-length array with flexible-array member
uapi: linux: fiemap.h: Replace zero-length array with flexible-array member
uapi: linux: dlm_device.h: Replace zero-length array with flexible-array member
tpm_eventlog.h: Replace zero-length array with flexible-array member
ti_wilink_st.h: Replace zero-length array with flexible-array member
swap.h: Replace zero-length array with flexible-array member
skbuff.h: Replace zero-length array with flexible-array member
sched: topology.h: Replace zero-length array with flexible-array member
rslib.h: Replace zero-length array with flexible-array member
rio.h: Replace zero-length array with flexible-array member
posix_acl.h: Replace zero-length array with flexible-array member
platform_data: wilco-ec.h: Replace zero-length array with flexible-array member
memcontrol.h: Replace zero-length array with flexible-array member
list_lru.h: Replace zero-length array with flexible-array member
lib: cpu_rmap: Replace zero-length array with flexible-array member
irq.h: Replace zero-length array with flexible-array member
ihex.h: Replace zero-length array with flexible-array member
igmp.h: Replace zero-length array with flexible-array member
genalloc.h: Replace zero-length array with flexible-array member
ethtool.h: Replace zero-length array with flexible-array member
...
Diffstat (limited to 'include/uapi')
-rw-r--r-- | include/uapi/linux/dlm_device.h | 4 | ||||
-rw-r--r-- | include/uapi/linux/fiemap.h | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/include/uapi/linux/dlm_device.h b/include/uapi/linux/dlm_device.h index f880d2831160..e83954c69fff 100644 --- a/include/uapi/linux/dlm_device.h +++ b/include/uapi/linux/dlm_device.h @@ -45,13 +45,13 @@ struct dlm_lock_params { void __user *bastaddr; struct dlm_lksb __user *lksb; char lvb[DLM_USER_LVB_LEN]; - char name[0]; + char name[]; }; struct dlm_lspace_params { __u32 flags; __u32 minor; - char name[0]; + char name[]; }; struct dlm_purge_params { diff --git a/include/uapi/linux/fiemap.h b/include/uapi/linux/fiemap.h index 8c0bc24d5d95..7a900b2377b6 100644 --- a/include/uapi/linux/fiemap.h +++ b/include/uapi/linux/fiemap.h @@ -34,7 +34,7 @@ struct fiemap { __u32 fm_mapped_extents;/* number of extents that were mapped (out) */ __u32 fm_extent_count; /* size of fm_extents array (in) */ __u32 fm_reserved; - struct fiemap_extent fm_extents[0]; /* array of mapped extents (out) */ + struct fiemap_extent fm_extents[]; /* array of mapped extents (out) */ }; #define FIEMAP_MAX_OFFSET (~0ULL) |