riscv: mm: Unconditionally sfence.vma for spurious fault

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Svvptc does not guarantee that it's safe to just return here. Since we
have already cleared our bit, if, theoretically, the bounded timeframe
for the accessed page to become valid still hasn't happened after sret,
we could fault again and actually crash.

Hopefully, these spurious faults should be rare enough that this is an
acceptable slowdown.

Cc: stable@vger.kernel.org
Fixes: 503638e0ba ("riscv: Stop emitting preventive sfence.vma for new vmalloc mappings")
Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn>
Link: https://patch.msgid.link/20260303-handle-kfence-protect-spurious-fault-v2-5-f80d8354d79d@iscas.ac.cn
Signed-off-by: Paul Walmsley <pjw@kernel.org>

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Vivian Wang 2026-03-03 13:29:49 +08:00 • committed by Paul Walmsley

parent 26c171fc48

commit 1b2c6b56a9

1 changed files with 5 additions and 2 deletions

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