4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 6ab7d47bcbf0144a8cb81536c2cead4cde18acfe ]
From Michael Cree:
"Bisection lead to commit b38d08f3181c ("percpu: restructure locking") as being the cause of lockups at initial boot on the kernel built for generic Alpha.
On a suggestion by Tejun Heo that:
So, the only thing I can think of is that it's calling spin_unlock_irq() while irq handling isn't set up yet. Can you please try the followings?
1. Convert all spin_[un]lock_irq() to spin_lock_irqsave/unlock_irqrestore()."
Fixes: b38d08f3181c ("percpu: restructure locking") Reported-and-tested-by: Michael Cree mcree@orcon.net.nz Acked-by: Tejun Heo tj@kernel.org Signed-off-by: Dennis Zhou dennis@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- mm/percpu-km.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/mm/percpu-km.c b/mm/percpu-km.c index 38de70ab1a0d..0f643dc2dc65 100644 --- a/mm/percpu-km.c +++ b/mm/percpu-km.c @@ -50,6 +50,7 @@ static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp) const int nr_pages = pcpu_group_sizes[0] >> PAGE_SHIFT; struct pcpu_chunk *chunk; struct page *pages; + unsigned long flags; int i;
chunk = pcpu_alloc_chunk(gfp); @@ -68,9 +69,9 @@ static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp) chunk->data = pages; chunk->base_addr = page_address(pages) - pcpu_group_offsets[0];
- spin_lock_irq(&pcpu_lock); + spin_lock_irqsave(&pcpu_lock, flags); pcpu_chunk_populated(chunk, 0, nr_pages, false); - spin_unlock_irq(&pcpu_lock); + spin_unlock_irqrestore(&pcpu_lock, flags);
pcpu_stats_chunk_alloc(); trace_percpu_create_chunk(chunk->base_addr);