From c2d81c24123361e5092c88e67d790097308c5b95 Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Sun, 1 Oct 2023 09:13:54 +0200 Subject: [PATCH] bcachefs: Use struct_size() Use struct_size() instead of hand writing it. This is less verbose and more robust. While at it, 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 checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). Signed-off-by: Christophe JAILLET Signed-off-by: Kent Overstreet --- fs/bcachefs/disk_groups.c | 3 +-- fs/bcachefs/super_types.h | 2 +- 2 files changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/bcachefs/disk_groups.c b/fs/bcachefs/disk_groups.c index 43aad8ba8cc9..3c8aa69b67ea 100644 --- a/fs/bcachefs/disk_groups.c +++ b/fs/bcachefs/disk_groups.c @@ -163,8 +163,7 @@ int bch2_sb_disk_groups_to_cpu(struct bch_fs *c) if (!groups) return 0; - cpu_g = kzalloc(sizeof(*cpu_g) + - sizeof(cpu_g->entries[0]) * nr_groups, GFP_KERNEL); + cpu_g = kzalloc(struct_size(cpu_g, entries, nr_groups), GFP_KERNEL); if (!cpu_g) return -BCH_ERR_ENOMEM_disk_groups_to_cpu; diff --git a/fs/bcachefs/super_types.h b/fs/bcachefs/super_types.h index 597a8db73585..78d6138db62d 100644 --- a/fs/bcachefs/super_types.h +++ b/fs/bcachefs/super_types.h @@ -46,7 +46,7 @@ struct bch_disk_group_cpu { struct bch_disk_groups_cpu { struct rcu_head rcu; unsigned nr; - struct bch_disk_group_cpu entries[]; + struct bch_disk_group_cpu entries[] __counted_by(nr); }; #endif /* _BCACHEFS_SUPER_TYPES_H */