There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2].
Refactor the code according to the use of a flexible-array member in struct stack_record, instead of a one-element array, and use the struct_size() helper to calculate the size for the allocation. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays Build-tested-by: kernel test robot <l...@intel.com> Link: https://lore.kernel.org/lkml/5f75876b.x9zdn10esic0qlhv%25...@intel.com/ Signed-off-by: Gustavo A. R. Silva <gustavo...@kernel.org> --- lib/stackdepot.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 2caffc64e4c8..c6106cfb7950 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -62,7 +62,7 @@ struct stack_record { u32 hash; /* Hash in the hastable */ u32 size; /* Number of frames in the stack */ union handle_parts handle; - unsigned long entries[1]; /* Variable-sized array of entries. */ + unsigned long entries[]; /* Variable-sized array of entries. */ }; static void *stack_slabs[STACK_ALLOC_MAX_SLABS]; @@ -104,9 +104,8 @@ static bool init_stack_slab(void **prealloc) static struct stack_record *depot_alloc_stack(unsigned long *entries, int size, u32 hash, void **prealloc, gfp_t alloc_flags) { - int required_size = offsetof(struct stack_record, entries) + - sizeof(unsigned long) * size; struct stack_record *stack; + size_t required_size = struct_size(stack, entries, size); required_size = ALIGN(required_size, 1 << STACK_ALLOC_ALIGN); -- 2.27.0
