diff options
| author | Erick Archer <erick.archer@gmx.com> | 2024-03-10 12:02:26 +0100 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2024-03-13 21:22:26 -0400 |
| commit | 3e48999816b1d1dba3ca40b1d7dbc324adb72fe2 (patch) | |
| tree | 7bfd6a22e34df4278a861a3ab052ac24924bb6d9 | |
| parent | 1fdb9685ed8b7b871632a3d348a948e1b53a17e5 (diff) | |
| download | vfs-3e48999816b1d1dba3ca40b1d7dbc324adb72fe2.tar.gz | |
bcachefs: Prefer struct_size over open coded arithmetic
This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows [1][2].
As the "op" variable is a pointer to "struct promote_op" and this
structure ends in a flexible array:
struct promote_op {
[...]
struct bio_vec bi_inline_vecs[];
};
and the "t" variable is a pointer to "struct journal_seq_blacklist_table"
and this structure also ends in a flexible array:
struct journal_seq_blacklist_table {
[...]
struct journal_seq_blacklist_table_entry {
u64 start;
u64 end;
bool dirty;
} entries[];
};
the preferred way in the kernel is to use the struct_size() helper to
do the arithmetic instead of the argument "size + size * count" in the
kzalloc() functions.
This way, the code is more readable and safer.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
Link: https://github.com/KSPP/linux/issues/160 [2]
Signed-off-by: Erick Archer <erick.archer@gmx.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
| -rw-r--r-- | fs/bcachefs/io_read.c | 2 | ||||
| -rw-r--r-- | fs/bcachefs/journal_seq_blacklist.c | 3 |
2 files changed, 2 insertions, 3 deletions
diff --git a/fs/bcachefs/io_read.c b/fs/bcachefs/io_read.c index 3c574d8873a1e..8a556e6d1ab6f 100644 --- a/fs/bcachefs/io_read.c +++ b/fs/bcachefs/io_read.c @@ -174,7 +174,7 @@ static struct promote_op *__promote_alloc(struct btree_trans *trans, if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_promote)) return ERR_PTR(-BCH_ERR_nopromote_no_writes); - op = kzalloc(sizeof(*op) + sizeof(struct bio_vec) * pages, GFP_KERNEL); + op = kzalloc(struct_size(op, bi_inline_vecs, pages), GFP_KERNEL); if (!op) { ret = -BCH_ERR_nopromote_enomem; goto err; diff --git a/fs/bcachefs/journal_seq_blacklist.c b/fs/bcachefs/journal_seq_blacklist.c index 5acc1276675c1..b5303874fc35b 100644 --- a/fs/bcachefs/journal_seq_blacklist.c +++ b/fs/bcachefs/journal_seq_blacklist.c @@ -141,8 +141,7 @@ int bch2_blacklist_table_initialize(struct bch_fs *c) if (!bl) return 0; - t = kzalloc(sizeof(*t) + sizeof(t->entries[0]) * nr, - GFP_KERNEL); + t = kzalloc(struct_size(t, entries, nr), GFP_KERNEL); if (!t) return -BCH_ERR_ENOMEM_blacklist_table_init; |