crypto: crct10dif-vpmsum - Fix missing preempt_disable()
authorMichael Ellerman <mpe@ellerman.id.au>
Thu, 20 Apr 2017 05:35:09 +0000 (15:35 +1000)
committerHerbert Xu <herbert@gondor.apana.org.au>
Fri, 21 Apr 2017 12:30:51 +0000 (20:30 +0800)
commit0f89f6e188fa929b6de49c00c73f5731a6bd6bac
tree10a4965ef59f1878b873f8ddbbdf017a64b72dc7
parenta9943a0ad19f4a23bb5c4217df0fb37feb7ac339
crypto: crct10dif-vpmsum - Fix missing preempt_disable()

In crct10dif_vpmsum() we call enable_kernel_altivec() without first
disabling preemption, which is not allowed.

It used to be sufficient just to call pagefault_disable(), because that
also disabled preemption. But the two were decoupled in commit 8222dbe21e79
("sched/preempt, mm/fault: Decouple preemption from the page fault
logic") in mid 2015.

The crct10dif-vpmsum code inherited this bug from the crc32c-vpmsum code
on which it was modelled.

So add the missing preempt_disable/enable(). We should also call
disable_kernel_fp(), although it does nothing by default, there is a
debug switch to make it active and all enables should be paired with
disables.

Fixes: b01df1c16c9a ("crypto: powerpc - Add CRC-T10DIF acceleration")
Acked-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
arch/powerpc/crypto/crct10dif-vpmsum_glue.c