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authorMichael Ellerman <mpe@ellerman.id.au>2017-04-20 15:35:09 +1000
committerHerbert Xu <herbert@gondor.apana.org.au>2017-04-21 20:30:51 +0800
commit0f89f6e188fa929b6de49c00c73f5731a6bd6bac (patch)
tree10a4965ef59f1878b873f8ddbbdf017a64b72dc7 /arch
parenta9943a0ad19f4a23bb5c4217df0fb37feb7ac339 (diff)
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/crypto/crct10dif-vpmsum_glue.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/powerpc/crypto/crct10dif-vpmsum_glue.c b/arch/powerpc/crypto/crct10dif-vpmsum_glue.c
index bebfc329f746..02ea277863d1 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;
}