releases/4.4.98/crypto-vmx-disable-preemption-to-enable-vsx-in-aes_ctr.c.patch

   1 From foo@baz Thu Nov  9 18:22:51 CET 2017
   2 From: Li Zhong <zhong@linux.vnet.ibm.com>
   3 Date: Fri, 20 Jan 2017 16:35:33 +0800
   4 Subject: crypto: vmx - disable preemption to enable vsx in aes_ctr.c
   5
   6 From: Li Zhong <zhong@linux.vnet.ibm.com>
   7
   8
   9 [ Upstream commit 7dede913fc2ab9c0d3bff3a49e26fa9e858b0c13 ]
  10
  11 Some preemptible check warnings were reported from enable_kernel_vsx(). This
  12 patch disables preemption in aes_ctr.c before enabling vsx, and they are now
  13 consistent with other files in the same directory.
  14
  15 Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
  16 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  17 Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
  18 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  19 ---
  20  drivers/crypto/vmx/aes_ctr.c |    6 ++++++
  21  1 file changed, 6 insertions(+)
  22
  23 --- a/drivers/crypto/vmx/aes_ctr.c
  24 +++ b/drivers/crypto/vmx/aes_ctr.c
  25 @@ -80,11 +80,13 @@ static int p8_aes_ctr_setkey(struct cryp
  26         int ret;
  27         struct p8_aes_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
  28
  29 +       preempt_disable();
  30         pagefault_disable();
  31         enable_kernel_altivec();
  32         enable_kernel_vsx();
  33         ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
  34         pagefault_enable();
  35 +       preempt_enable();
  36
  37         ret += crypto_blkcipher_setkey(ctx->fallback, key, keylen);
  38         return ret;
  39 @@ -99,11 +101,13 @@ static void p8_aes_ctr_final(struct p8_a
  40         u8 *dst = walk->dst.virt.addr;
  41         unsigned int nbytes = walk->nbytes;
  42
  43 +       preempt_disable();
  44         pagefault_disable();
  45         enable_kernel_altivec();
  46         enable_kernel_vsx();
  47         aes_p8_encrypt(ctrblk, keystream, &ctx->enc_key);
  48         pagefault_enable();
  49 +       preempt_enable();
  50
  51         crypto_xor(keystream, src, nbytes);
  52         memcpy(dst, keystream, nbytes);
  53 @@ -132,6 +136,7 @@ static int p8_aes_ctr_crypt(struct blkci
  54                 blkcipher_walk_init(&walk, dst, src, nbytes);
  55                 ret = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
  56                 while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
  57 +                       preempt_disable();
  58                         pagefault_disable();
  59                         enable_kernel_altivec();
  60                         enable_kernel_vsx();
  61 @@ -143,6 +148,7 @@ static int p8_aes_ctr_crypt(struct blkci
  62                                                     &ctx->enc_key,
  63                                                     walk.iv);
  64                         pagefault_enable();
  65 +                       preempt_enable();
  66
  67                         /* We need to update IV mostly for last bytes/round */
  68                         inc = (nbytes & AES_BLOCK_MASK) / AES_BLOCK_SIZE;