On 8/10/24 00:05, Herbert Xu wrote:
Waiman Long <longman@xxxxxxxxxx> wrote:diff --git a/kernel/padata.c b/kernel/padata.c index 53f4bc912712..0fa6c2895460 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -517,6 +517,13 @@ void __init padata_do_multithreaded(struct padata_mt_job *job) ps.chunk_size = max(ps.chunk_size, job->min_chunk); ps.chunk_size = roundup(ps.chunk_size, job->align); + /* + * chunk_size can be 0 if the caller sets min_chunk to 0. So force it + * to at least 1 to prevent divide-by-0 panic in padata_mt_helper().` + */ + if (!ps.chunk_size) + ps.chunk_size = 1U;Perhaps change the first ps.chunk_size assignment to use DIV_ROUND_UP instead?
I think DIV_ROUND_UP() will exactly the same problem that if chunk_size is 0, you still got a 0 result. round_up() only if the 2nd argument is a power of 2 while with DIV_ROUND_UP(), the second argument can be any number except 0.
Cheers, Longman
