From 3e48999816b1d1dba3ca40b1d7dbc324adb72fe2 Mon Sep 17 00:00:00 2001 From: Erick Archer Date: Sun, 10 Mar 2024 12:02:26 +0100 Subject: 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 Signed-off-by: Kent Overstreet --- fs/bcachefs/io_read.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/bcachefs/io_read.c') diff --git a/fs/bcachefs/io_read.c b/fs/bcachefs/io_read.c index 3c574d8873a1..8a556e6d1ab6 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; -- cgit