From 0f89f6e188fa929b6de49c00c73f5731a6bd6bac Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Thu, 20 Apr 2017 15:35:09 +1000 Subject: [PATCH] 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 Signed-off-by: Michael Ellerman Signed-off-by: Herbert Xu --- arch/powerpc/crypto/crct10dif-vpmsum_glue.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/powerpc/crypto/crct10dif-vpmsum_glue.c b/arch/powerpc/crypto/crct10dif-vpmsum_glue.c index bebfc329..02ea277 100644 --- a/arch/powerpc/crypto/crct10dif-vpmsum_glue.c +++ b/arch/powerpc/crypto/crct10dif-vpmsum_glue.c @@ -44,10 +44,13 @@ static u16 crct10dif_vpmsum(u16 crci, unsigned char const *p, size_t len) if (len & ~VMX_ALIGN_MASK) { crc <<= 16; + preempt_disable(); pagefault_disable(); enable_kernel_altivec(); crc = __crct10dif_vpmsum(crc, p, len & ~VMX_ALIGN_MASK); + disable_kernel_altivec(); pagefault_enable(); + preempt_enable(); crc >>= 16; } -- 2.7.4