5.10-stable review patch. If anyone has any objections, please let me know.
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From: Kamlesh Gurudasani kamlesh@ti.com
[ Upstream commit 24cc57d8faaa4060fd58adf810b858fcfb71a02f ]
In the case where we are forcing the ps.chunk_size to be at least 1, we are ignoring the caller's alignment.
Move the forcing of ps.chunk_size to be at least 1 before rounding it up to caller's alignment, so that caller's alignment is honored.
While at it, use max() to force the ps.chunk_size to be at least 1 to improve readability.
Fixes: 6d45e1c948a8 ("padata: Fix possible divide-by-0 panic in padata_mt_helper()") Signed-off-by: Kamlesh Gurudasani kamlesh@ti.com Acked-by: Waiman Long longman@redhat.com Acked-by: Daniel Jordan daniel.m.jordan@oracle.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/padata.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/padata.c b/kernel/padata.c index 2a514cf8379b4..41d5bf2fa2ad9 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -516,9 +516,12 @@ void __init padata_do_multithreaded(struct padata_mt_job *job) * thread function. Load balance large jobs between threads by * increasing the number of chunks, guarantee at least the minimum * chunk size from the caller, and honor the caller's alignment. + * Ensure chunk_size is at least 1 to prevent divide-by-0 + * panic in padata_mt_helper(). */ ps.chunk_size = job->size / (ps.nworks * load_balance_factor); ps.chunk_size = max(ps.chunk_size, job->min_chunk); + ps.chunk_size = max(ps.chunk_size, 1ul); ps.chunk_size = roundup(ps.chunk_size, job->align);
/*