On Sat, Oct 26, 2024 at 05:47:04PM +0200, Thorsten Blum wrote: > Add the __counted_by compiler attribute to the flexible array member b > to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and > CONFIG_FORTIFY_SOURCE. > > Use struct_size() to calculate the number of bytes to be allocated. > > Update bucket_gens->nbuckets and bucket_gens->nbuckets_minus_first when > resizing. > > Compile-tested only. > > Signed-off-by: Thorsten Blum <[email protected]>
I can take this patch without it being tested, but please have a look at ktest: https://evilpiepirate.org/git/ktest.git/ that's where all the bcachefs tests live, and it's a nice testing and debugging tool. The CI runs the same tests, and I can give you an account there as well. > --- > fs/bcachefs/buckets.c | 13 ++++++++----- > fs/bcachefs/buckets_types.h | 2 +- > 2 files changed, 9 insertions(+), 6 deletions(-) > > diff --git a/fs/bcachefs/buckets.c b/fs/bcachefs/buckets.c > index ec7d9a59bea9..8bd17667e243 100644 > --- a/fs/bcachefs/buckets.c > +++ b/fs/bcachefs/buckets.c > @@ -1266,8 +1266,9 @@ int bch2_dev_buckets_resize(struct bch_fs *c, struct > bch_dev *ca, u64 nbuckets) > > BUG_ON(resize && ca->buckets_nouse); > > - if (!(bucket_gens = kvmalloc(sizeof(struct bucket_gens) + > nbuckets, > - GFP_KERNEL|__GFP_ZERO))) { > + bucket_gens = kvmalloc(struct_size(bucket_gens, b, nbuckets), > + GFP_KERNEL|__GFP_ZERO); > + if (!bucket_gens) { > ret = -BCH_ERR_ENOMEM_bucket_gens; > goto err; > } > @@ -1285,11 +1286,13 @@ int bch2_dev_buckets_resize(struct bch_fs *c, struct > bch_dev *ca, u64 nbuckets) > old_bucket_gens = rcu_dereference_protected(ca->bucket_gens, 1); > > if (resize) { > - size_t n = min(bucket_gens->nbuckets, > old_bucket_gens->nbuckets); > - > + bucket_gens->nbuckets = min(bucket_gens->nbuckets, > + old_bucket_gens->nbuckets); > + bucket_gens->nbuckets_minus_first = > + bucket_gens->nbuckets - bucket_gens->first_bucket; > memcpy(bucket_gens->b, > old_bucket_gens->b, > - n); > + bucket_gens->nbuckets); > } > > rcu_assign_pointer(ca->bucket_gens, bucket_gens); > diff --git a/fs/bcachefs/buckets_types.h b/fs/bcachefs/buckets_types.h > index 28bd09a253c8..7174047b8e92 100644 > --- a/fs/bcachefs/buckets_types.h > +++ b/fs/bcachefs/buckets_types.h > @@ -24,7 +24,7 @@ struct bucket_gens { > u16 first_bucket; > size_t nbuckets; > size_t nbuckets_minus_first; > - u8 b[]; > + u8 b[] __counted_by(nbuckets); > }; > > struct bch_dev_usage { > -- > 2.47.0 >
