This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows [1][2].
As the "t" variable is a pointer to "struct journal_seq_blacklist_table"
and this structure 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() function.
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 <[email protected]>
---
fs/bcachefs/journal_seq_blacklist.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/fs/bcachefs/journal_seq_blacklist.c
b/fs/bcachefs/journal_seq_blacklist.c
index 024c9b1b323f..2c2490aa15fe 100644
--- a/fs/bcachefs/journal_seq_blacklist.c
+++ b/fs/bcachefs/journal_seq_blacklist.c
@@ -165,8 +165,7 @@ 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;
--
2.25.1
