[PATCH RFC 13/15] powerpc: enable_kernel_altivec() requires disabled preemption

From: David Hildenbrand
Date: Wed May 06 2015 - 13:51:41 EST

enable_kernel_altivec() has to be called with disabled preemption.
Let's make this explicit, to prepare for pagefault_disable() not
touching preemption anymore.

Signed-off-by: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/lib/vmx-helper.c | 11 ++++++-----
drivers/crypto/vmx/aes.c | 8 +++++++-
drivers/crypto/vmx/aes_cbc.c | 6 ++++++
drivers/crypto/vmx/ghash.c | 8 ++++++++
4 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/lib/vmx-helper.c b/arch/powerpc/lib/vmx-helper.c
index 3cf529c..ac93a3b 100644
--- a/arch/powerpc/lib/vmx-helper.c
+++ b/arch/powerpc/lib/vmx-helper.c
@@ -27,11 +27,11 @@ int enter_vmx_usercopy(void)
if (in_interrupt())
return 0;

- /* This acts as preempt_disable() as well and will make
- * enable_kernel_altivec(). We need to disable page faults
- * as they can call schedule and thus make us lose the VMX
- * context. So on page faults, we just fail which will cause
- * a fallback to the normal non-vmx copy.
+ preempt_disable();
+ /*
+ * We need to disable page faults as they can call schedule and
+ * thus make us lose the VMX context. So on page faults, we just
+ * fail which will cause a fallback to the normal non-vmx copy.
*/
pagefault_disable();

@@ -47,6 +47,7 @@ int enter_vmx_usercopy(void)
int exit_vmx_usercopy(void)
{
pagefault_enable();
+ preempt_enable();
return 0;
}

diff --git a/drivers/crypto/vmx/aes.c b/drivers/crypto/vmx/aes.c
index ab300ea..a9064e3 100644
--- a/drivers/crypto/vmx/aes.c
+++ b/drivers/crypto/vmx/aes.c
@@ -78,12 +78,14 @@ static int p8_aes_setkey(struct crypto_tfm *tfm, const u8 *key,
int ret;
struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);

+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
pagefault_enable();
-
+ preempt_enable();
+
ret += crypto_cipher_setkey(ctx->fallback, key, keylen);
return ret;
}
@@ -95,10 +97,12 @@ static void p8_aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
if (in_interrupt()) {
crypto_cipher_encrypt_one(ctx->fallback, dst, src);
} else {
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
aes_p8_encrypt(src, dst, &ctx->enc_key);
pagefault_enable();
+ preempt_enable();
}
}

@@ -109,10 +113,12 @@ static void p8_aes_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
if (in_interrupt()) {
crypto_cipher_decrypt_one(ctx->fallback, dst, src);
} else {
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
aes_p8_decrypt(src, dst, &ctx->dec_key);
pagefault_enable();
+ preempt_enable();
}
}

diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
index 1a559b7..477284a 100644
--- a/drivers/crypto/vmx/aes_cbc.c
+++ b/drivers/crypto/vmx/aes_cbc.c
@@ -79,11 +79,13 @@ static int p8_aes_cbc_setkey(struct crypto_tfm *tfm, const u8 *key,
int ret;
struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);

+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
pagefault_enable();
+ preempt_enable();

ret += crypto_blkcipher_setkey(ctx->fallback, key, keylen);
return ret;
@@ -106,6 +108,7 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
if (in_interrupt()) {
ret = crypto_blkcipher_encrypt(&fallback_desc, dst, src, nbytes);
} else {
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();

@@ -119,6 +122,7 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
}

pagefault_enable();
+ preempt_enable();
}

return ret;
@@ -141,6 +145,7 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
if (in_interrupt()) {
ret = crypto_blkcipher_decrypt(&fallback_desc, dst, src, nbytes);
} else {
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();

@@ -154,6 +159,7 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
}

pagefault_enable();
+ preempt_enable();
}

return ret;
diff --git a/drivers/crypto/vmx/ghash.c b/drivers/crypto/vmx/ghash.c
index d0ffe27..f255ec4 100644
--- a/drivers/crypto/vmx/ghash.c
+++ b/drivers/crypto/vmx/ghash.c
@@ -114,11 +114,13 @@ static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key,
if (keylen != GHASH_KEY_LEN)
return -EINVAL;

+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
enable_kernel_fp();
gcm_init_p8(ctx->htable, (const u64 *) key);
pagefault_enable();
+ preempt_enable();
return crypto_shash_setkey(ctx->fallback, key, keylen);
}

@@ -140,23 +142,27 @@ static int p8_ghash_update(struct shash_desc *desc,
}
memcpy(dctx->buffer + dctx->bytes, src,
GHASH_DIGEST_SIZE - dctx->bytes);
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
enable_kernel_fp();
gcm_ghash_p8(dctx->shash, ctx->htable, dctx->buffer,
GHASH_DIGEST_SIZE);
pagefault_enable();
+ preempt_enable();
src += GHASH_DIGEST_SIZE - dctx->bytes;
srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
dctx->bytes = 0;
}
len = srclen & ~(GHASH_DIGEST_SIZE - 1);
if (len) {
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
enable_kernel_fp();
gcm_ghash_p8(dctx->shash, ctx->htable, src, len);
pagefault_enable();
+ preempt_enable();
src += len;
srclen -= len;
}
@@ -180,12 +186,14 @@ static int p8_ghash_final(struct shash_desc *desc, u8 *out)
if (dctx->bytes) {
for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
dctx->buffer[i] = 0;
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
enable_kernel_fp();
gcm_ghash_p8(dctx->shash, ctx->htable, dctx->buffer,
GHASH_DIGEST_SIZE);
pagefault_enable();
+ preempt_enable();
dctx->bytes = 0;
}
memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
--
2.1.4

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