Re: [PATCH 01/25] xor: assert that xor_blocks is not called from interrupt context
From: Peter Zijlstra <peterz@infradead.org>
Date: 2026-02-27 14:25:33
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linux-alpha, linux-arch, linux-btrfs, linux-crypto, linux-raid, linux-riscv, linux-s390, linux-um, lkml, loongarch, sparclinux
On Thu, Feb 26, 2026 at 07:10:13AM -0800, Christoph Hellwig wrote:
quoted hunk ↗ jump to hunk
Most of the optimized xor_blocks versions require FPU/vector registers, which generally are not supported in interrupt context. Both callers already are in user context, so enforce this at the highest level. Signed-off-by: Christoph Hellwig <hch@lst.de> --- crypto/xor.c | 2 ++ 1 file changed, 2 insertions(+)diff --git a/crypto/xor.c b/crypto/xor.c index f39621a57bb3..864f3604e867 100644 --- a/crypto/xor.c +++ b/crypto/xor.c@@ -28,6 +28,8 @@ xor_blocks(unsigned int src_count, unsigned int bytes, void *dest, void **srcs) { unsigned long *p1, *p2, *p3, *p4; + WARN_ON_ONCE(in_interrupt());
Your changelog makes it sound like you want: WARN_ON_ONCE(!in_task()); But perhaps something like so: lockdep_assert_preempt_enabled(); Would do? That ensures we are in preemptible context, which is much the same. That also ensures the cost of this assertion is only paid on debug kernels.
p1 = (unsigned long *) srcs[0];
if (src_count == 1) {
active_template->do_2(bytes, dest, p1);
--
2.47.3