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| author | Gustavo A. R. Silva <gustavoars@kernel.org> | 2023-12-18 18:24:53 -0600 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2024-01-01 11:47:41 -0500 |
| commit | 4c26dea1c096138b6e7c49c4886e68fbf6013217 (patch) | |
| tree | 6e8bc558043d4fec2bb09c3cdd8a8b4cd21082c2 /fs | |
| parent | ac19c4c3d02e19b365209d2cee409671e1fb66bb (diff) | |
bcachefs: Replace zero-length array with flex-array member and use __counted_by
Fake flexible arrays (zero-length and one-element arrays) are
deprecated, and should be replaced by flexible-array members.
So, replace zero-length array with a flexible-array member in
`struct bch_ioctl_fsck_offline`.
Also annotate array `devs` with `__counted_by()` to prepare for the
coming implementation by GCC and Clang of the `__counted_by` attribute.
Flexible array members annotated with `__counted_by` can have their
accesses bounds-checked at run-time via `CONFIG_UBSAN_BOUNDS` (for
array indexing) and `CONFIG_FORTIFY_SOURCE` (for strcpy/memcpy-family
functions).
This fixes the following -Warray-bounds warnings:
fs/bcachefs/chardev.c: In function 'bch2_ioctl_fsck_offline':
fs/bcachefs/chardev.c:363:34: warning: array subscript 0 is outside array bounds of '__u64[0]' {aka 'long long unsigned int[]'} [-Warray-bounds=]
363 | if (copy_from_user(devs, &user_arg->devs[0], sizeof(user_arg->devs[0]) * arg.nr_devs)) {
| ^~~~~~~~~~~~~~~~~~
In file included from fs/bcachefs/chardev.c:5:
fs/bcachefs/bcachefs_ioctl.h:400:33: note: while referencing 'devs'
400 | __u64 devs[0];
This results in no differences in binary output.
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/bcachefs/bcachefs_ioctl.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/bcachefs/bcachefs_ioctl.h b/fs/bcachefs/bcachefs_ioctl.h index 21f81b16f24e..4b8fba754b1c 100644 --- a/fs/bcachefs/bcachefs_ioctl.h +++ b/fs/bcachefs/bcachefs_ioctl.h @@ -397,7 +397,7 @@ struct bch_ioctl_fsck_offline { __u64 flags; __u64 opts; /* string */ __u64 nr_devs; - __u64 devs[0]; + __u64 devs[] __counted_by(nr_devs); }; /* |